Jeep GC 95 Climate Control Code Problem
Guest
Posts: n/a
Jeep GC 95 Climate Control Code Problem
Hi folks - hope someone can help...
I've searched the web high and low to see the cause of this problem,
but whilst I see a few people have suffered the same plight - I don't
see any description of the problem and what can be done to cure it.
I have a 1995 JGC that has been a wonder, since it's still looking
great and going strong with 240K on the clock. There are issues popping
up here and there, most which I can live with or fix.
But now with summer coming to CA I have one I must fix.
The fan of the climate control system no longer pumps any air through
unless on the high setting - so unless it is on high, the fan is not
working at all (regardless of a/c setting). When turned to something
other than high the code ER appears in the LED where the temp would
normally be.
Cannot find anything in the book - and I've check fuses etc...
This was an intermittent problem for a while - now it's a full time
one.
I don't want to go to a dealer and have them try and sell me a new back
axle...
Anyone any ideas?
Any help most highly appreciated - I want this car to keep on going,
she's not ready for retirement yet!
Thanks.
I've searched the web high and low to see the cause of this problem,
but whilst I see a few people have suffered the same plight - I don't
see any description of the problem and what can be done to cure it.
I have a 1995 JGC that has been a wonder, since it's still looking
great and going strong with 240K on the clock. There are issues popping
up here and there, most which I can live with or fix.
But now with summer coming to CA I have one I must fix.
The fan of the climate control system no longer pumps any air through
unless on the high setting - so unless it is on high, the fan is not
working at all (regardless of a/c setting). When turned to something
other than high the code ER appears in the LED where the temp would
normally be.
Cannot find anything in the book - and I've check fuses etc...
This was an intermittent problem for a while - now it's a full time
one.
I don't want to go to a dealer and have them try and sell me a new back
axle...
Anyone any ideas?
Any help most highly appreciated - I want this car to keep on going,
she's not ready for retirement yet!
Thanks.
Guest
Posts: n/a
Re: Jeep GC 95 Climate Control Code Problem
dmccall did pass the time by typing:
> The fan of the climate control system no longer pumps any air through
> unless on the high setting - so unless it is on high, the fan is not
> working at all (regardless of a/c setting). When turned to something
> other than high the code ER appears in the LED where the temp would
> normally be.
ER=error, the AC system has thrown an error code.
On the manual version that is caused by a blown resistor pack, but on
the automatic system it's a power module and relay combination that is
located by the blower motor. (don't remember exactly where, but if
you follow the blower wires you will find it.)
The power module controls lower speeds and the relay runs the high
speed. So if it's on high then your relay is ok, but the power module
is probably toast.
When the ER pops up, press either A/C or Recirc and the codes should
scroll by.
I've got some data on the earlier system but nothing specific for your
year. 93 should be the same as 95 for the ATC system.
--
DougW
> The fan of the climate control system no longer pumps any air through
> unless on the high setting - so unless it is on high, the fan is not
> working at all (regardless of a/c setting). When turned to something
> other than high the code ER appears in the LED where the temp would
> normally be.
ER=error, the AC system has thrown an error code.
On the manual version that is caused by a blown resistor pack, but on
the automatic system it's a power module and relay combination that is
located by the blower motor. (don't remember exactly where, but if
you follow the blower wires you will find it.)
The power module controls lower speeds and the relay runs the high
speed. So if it's on high then your relay is ok, but the power module
is probably toast.
When the ER pops up, press either A/C or Recirc and the codes should
scroll by.
I've got some data on the earlier system but nothing specific for your
year. 93 should be the same as 95 for the ATC system.
--
DougW
Guest
Posts: n/a
Re: Jeep GC 95 Climate Control Code Problem
dmccall did pass the time by typing:
> The fan of the climate control system no longer pumps any air through
> unless on the high setting - so unless it is on high, the fan is not
> working at all (regardless of a/c setting). When turned to something
> other than high the code ER appears in the LED where the temp would
> normally be.
ER=error, the AC system has thrown an error code.
On the manual version that is caused by a blown resistor pack, but on
the automatic system it's a power module and relay combination that is
located by the blower motor. (don't remember exactly where, but if
you follow the blower wires you will find it.)
The power module controls lower speeds and the relay runs the high
speed. So if it's on high then your relay is ok, but the power module
is probably toast.
When the ER pops up, press either A/C or Recirc and the codes should
scroll by.
I've got some data on the earlier system but nothing specific for your
year. 93 should be the same as 95 for the ATC system.
--
DougW
> The fan of the climate control system no longer pumps any air through
> unless on the high setting - so unless it is on high, the fan is not
> working at all (regardless of a/c setting). When turned to something
> other than high the code ER appears in the LED where the temp would
> normally be.
ER=error, the AC system has thrown an error code.
On the manual version that is caused by a blown resistor pack, but on
the automatic system it's a power module and relay combination that is
located by the blower motor. (don't remember exactly where, but if
you follow the blower wires you will find it.)
The power module controls lower speeds and the relay runs the high
speed. So if it's on high then your relay is ok, but the power module
is probably toast.
When the ER pops up, press either A/C or Recirc and the codes should
scroll by.
I've got some data on the earlier system but nothing specific for your
year. 93 should be the same as 95 for the ATC system.
--
DougW
Guest
Posts: n/a
Re: Jeep GC 95 Climate Control Code Problem
dmccall did pass the time by typing:
> The fan of the climate control system no longer pumps any air through
> unless on the high setting - so unless it is on high, the fan is not
> working at all (regardless of a/c setting). When turned to something
> other than high the code ER appears in the LED where the temp would
> normally be.
ER=error, the AC system has thrown an error code.
On the manual version that is caused by a blown resistor pack, but on
the automatic system it's a power module and relay combination that is
located by the blower motor. (don't remember exactly where, but if
you follow the blower wires you will find it.)
The power module controls lower speeds and the relay runs the high
speed. So if it's on high then your relay is ok, but the power module
is probably toast.
When the ER pops up, press either A/C or Recirc and the codes should
scroll by.
I've got some data on the earlier system but nothing specific for your
year. 93 should be the same as 95 for the ATC system.
--
DougW
> The fan of the climate control system no longer pumps any air through
> unless on the high setting - so unless it is on high, the fan is not
> working at all (regardless of a/c setting). When turned to something
> other than high the code ER appears in the LED where the temp would
> normally be.
ER=error, the AC system has thrown an error code.
On the manual version that is caused by a blown resistor pack, but on
the automatic system it's a power module and relay combination that is
located by the blower motor. (don't remember exactly where, but if
you follow the blower wires you will find it.)
The power module controls lower speeds and the relay runs the high
speed. So if it's on high then your relay is ok, but the power module
is probably toast.
When the ER pops up, press either A/C or Recirc and the codes should
scroll by.
I've got some data on the earlier system but nothing specific for your
year. 93 should be the same as 95 for the ATC system.
--
DougW
Guest
Posts: n/a
Re: Jeep GC 95 Climate Control Code Problem
DougW proclaimed:
> dmccall did pass the time by typing:
>
>
>>The fan of the climate control system no longer pumps any air through
>>unless on the high setting - so unless it is on high, the fan is not
>>working at all (regardless of a/c setting). When turned to something
>>other than high the code ER appears in the LED where the temp would
>>normally be.
>
>
> ER=error, the AC system has thrown an error code.
>
> On the manual version that is caused by a blown resistor pack, but on
> the automatic system it's a power module and relay combination that is
> located by the blower motor. (don't remember exactly where, but if
> you follow the blower wires you will find it.)
> The power module controls lower speeds and the relay runs the high
> speed. So if it's on high then your relay is ok, but the power module
> is probably toast.
>
> When the ER pops up, press either A/C or Recirc and the codes should
> scroll by.
>
> I've got some data on the earlier system but nothing specific for your
> year. 93 should be the same as 95 for the ATC system.
>
On the '95
If you don't see codes by pressing either A/C or RECIRC, [you will also
see the little stickman if that works] go to diag mode.
Press both A/C and RECIRC and hold down. Turn the ATC **** one click
clockwise. All the segments in the display come on.
Let go of A/C and RECIRC and you should see 00 in the display with no
stickman.
Push either A/C or RECIRC once. You should see the stickman again.
Write down the fault codes you see at this point. 25 or 29 means the
ATC module is toast and the rest of the codes may be gibberish.
From there, you can check a few of the major circuits. Just turn the
ATC **** until you see a number, then push the A/C button and record the
value displayed. Caution, the tests are mixed with read input value and
test output circuit all jumbled together.
Test I/O Subsystem Values
01 In Blower A/D OC, SC, or 00-255 or ?
02 In Blower Feedback ? or 00-255
03 Out 00-255 sets blower speed
04 Out Blower High 00=off 01= set blower high relay on.
Those would be the main ones. My guess is similar to Doug's, the blower
control is toast. The relay is enough to get high speed only. If you
ever smelled magic smoke, the controller probably shorted out, otherwise
is either open or the input from the ATC panel isn't getting to it.
> dmccall did pass the time by typing:
>
>
>>The fan of the climate control system no longer pumps any air through
>>unless on the high setting - so unless it is on high, the fan is not
>>working at all (regardless of a/c setting). When turned to something
>>other than high the code ER appears in the LED where the temp would
>>normally be.
>
>
> ER=error, the AC system has thrown an error code.
>
> On the manual version that is caused by a blown resistor pack, but on
> the automatic system it's a power module and relay combination that is
> located by the blower motor. (don't remember exactly where, but if
> you follow the blower wires you will find it.)
> The power module controls lower speeds and the relay runs the high
> speed. So if it's on high then your relay is ok, but the power module
> is probably toast.
>
> When the ER pops up, press either A/C or Recirc and the codes should
> scroll by.
>
> I've got some data on the earlier system but nothing specific for your
> year. 93 should be the same as 95 for the ATC system.
>
On the '95
If you don't see codes by pressing either A/C or RECIRC, [you will also
see the little stickman if that works] go to diag mode.
Press both A/C and RECIRC and hold down. Turn the ATC **** one click
clockwise. All the segments in the display come on.
Let go of A/C and RECIRC and you should see 00 in the display with no
stickman.
Push either A/C or RECIRC once. You should see the stickman again.
Write down the fault codes you see at this point. 25 or 29 means the
ATC module is toast and the rest of the codes may be gibberish.
From there, you can check a few of the major circuits. Just turn the
ATC **** until you see a number, then push the A/C button and record the
value displayed. Caution, the tests are mixed with read input value and
test output circuit all jumbled together.
Test I/O Subsystem Values
01 In Blower A/D OC, SC, or 00-255 or ?
02 In Blower Feedback ? or 00-255
03 Out 00-255 sets blower speed
04 Out Blower High 00=off 01= set blower high relay on.
Those would be the main ones. My guess is similar to Doug's, the blower
control is toast. The relay is enough to get high speed only. If you
ever smelled magic smoke, the controller probably shorted out, otherwise
is either open or the input from the ATC panel isn't getting to it.
Guest
Posts: n/a
Re: Jeep GC 95 Climate Control Code Problem
DougW proclaimed:
> dmccall did pass the time by typing:
>
>
>>The fan of the climate control system no longer pumps any air through
>>unless on the high setting - so unless it is on high, the fan is not
>>working at all (regardless of a/c setting). When turned to something
>>other than high the code ER appears in the LED where the temp would
>>normally be.
>
>
> ER=error, the AC system has thrown an error code.
>
> On the manual version that is caused by a blown resistor pack, but on
> the automatic system it's a power module and relay combination that is
> located by the blower motor. (don't remember exactly where, but if
> you follow the blower wires you will find it.)
> The power module controls lower speeds and the relay runs the high
> speed. So if it's on high then your relay is ok, but the power module
> is probably toast.
>
> When the ER pops up, press either A/C or Recirc and the codes should
> scroll by.
>
> I've got some data on the earlier system but nothing specific for your
> year. 93 should be the same as 95 for the ATC system.
>
On the '95
If you don't see codes by pressing either A/C or RECIRC, [you will also
see the little stickman if that works] go to diag mode.
Press both A/C and RECIRC and hold down. Turn the ATC **** one click
clockwise. All the segments in the display come on.
Let go of A/C and RECIRC and you should see 00 in the display with no
stickman.
Push either A/C or RECIRC once. You should see the stickman again.
Write down the fault codes you see at this point. 25 or 29 means the
ATC module is toast and the rest of the codes may be gibberish.
From there, you can check a few of the major circuits. Just turn the
ATC **** until you see a number, then push the A/C button and record the
value displayed. Caution, the tests are mixed with read input value and
test output circuit all jumbled together.
Test I/O Subsystem Values
01 In Blower A/D OC, SC, or 00-255 or ?
02 In Blower Feedback ? or 00-255
03 Out 00-255 sets blower speed
04 Out Blower High 00=off 01= set blower high relay on.
Those would be the main ones. My guess is similar to Doug's, the blower
control is toast. The relay is enough to get high speed only. If you
ever smelled magic smoke, the controller probably shorted out, otherwise
is either open or the input from the ATC panel isn't getting to it.
> dmccall did pass the time by typing:
>
>
>>The fan of the climate control system no longer pumps any air through
>>unless on the high setting - so unless it is on high, the fan is not
>>working at all (regardless of a/c setting). When turned to something
>>other than high the code ER appears in the LED where the temp would
>>normally be.
>
>
> ER=error, the AC system has thrown an error code.
>
> On the manual version that is caused by a blown resistor pack, but on
> the automatic system it's a power module and relay combination that is
> located by the blower motor. (don't remember exactly where, but if
> you follow the blower wires you will find it.)
> The power module controls lower speeds and the relay runs the high
> speed. So if it's on high then your relay is ok, but the power module
> is probably toast.
>
> When the ER pops up, press either A/C or Recirc and the codes should
> scroll by.
>
> I've got some data on the earlier system but nothing specific for your
> year. 93 should be the same as 95 for the ATC system.
>
On the '95
If you don't see codes by pressing either A/C or RECIRC, [you will also
see the little stickman if that works] go to diag mode.
Press both A/C and RECIRC and hold down. Turn the ATC **** one click
clockwise. All the segments in the display come on.
Let go of A/C and RECIRC and you should see 00 in the display with no
stickman.
Push either A/C or RECIRC once. You should see the stickman again.
Write down the fault codes you see at this point. 25 or 29 means the
ATC module is toast and the rest of the codes may be gibberish.
From there, you can check a few of the major circuits. Just turn the
ATC **** until you see a number, then push the A/C button and record the
value displayed. Caution, the tests are mixed with read input value and
test output circuit all jumbled together.
Test I/O Subsystem Values
01 In Blower A/D OC, SC, or 00-255 or ?
02 In Blower Feedback ? or 00-255
03 Out 00-255 sets blower speed
04 Out Blower High 00=off 01= set blower high relay on.
Those would be the main ones. My guess is similar to Doug's, the blower
control is toast. The relay is enough to get high speed only. If you
ever smelled magic smoke, the controller probably shorted out, otherwise
is either open or the input from the ATC panel isn't getting to it.
Guest
Posts: n/a
Re: Jeep GC 95 Climate Control Code Problem
DougW proclaimed:
> dmccall did pass the time by typing:
>
>
>>The fan of the climate control system no longer pumps any air through
>>unless on the high setting - so unless it is on high, the fan is not
>>working at all (regardless of a/c setting). When turned to something
>>other than high the code ER appears in the LED where the temp would
>>normally be.
>
>
> ER=error, the AC system has thrown an error code.
>
> On the manual version that is caused by a blown resistor pack, but on
> the automatic system it's a power module and relay combination that is
> located by the blower motor. (don't remember exactly where, but if
> you follow the blower wires you will find it.)
> The power module controls lower speeds and the relay runs the high
> speed. So if it's on high then your relay is ok, but the power module
> is probably toast.
>
> When the ER pops up, press either A/C or Recirc and the codes should
> scroll by.
>
> I've got some data on the earlier system but nothing specific for your
> year. 93 should be the same as 95 for the ATC system.
>
On the '95
If you don't see codes by pressing either A/C or RECIRC, [you will also
see the little stickman if that works] go to diag mode.
Press both A/C and RECIRC and hold down. Turn the ATC **** one click
clockwise. All the segments in the display come on.
Let go of A/C and RECIRC and you should see 00 in the display with no
stickman.
Push either A/C or RECIRC once. You should see the stickman again.
Write down the fault codes you see at this point. 25 or 29 means the
ATC module is toast and the rest of the codes may be gibberish.
From there, you can check a few of the major circuits. Just turn the
ATC **** until you see a number, then push the A/C button and record the
value displayed. Caution, the tests are mixed with read input value and
test output circuit all jumbled together.
Test I/O Subsystem Values
01 In Blower A/D OC, SC, or 00-255 or ?
02 In Blower Feedback ? or 00-255
03 Out 00-255 sets blower speed
04 Out Blower High 00=off 01= set blower high relay on.
Those would be the main ones. My guess is similar to Doug's, the blower
control is toast. The relay is enough to get high speed only. If you
ever smelled magic smoke, the controller probably shorted out, otherwise
is either open or the input from the ATC panel isn't getting to it.
> dmccall did pass the time by typing:
>
>
>>The fan of the climate control system no longer pumps any air through
>>unless on the high setting - so unless it is on high, the fan is not
>>working at all (regardless of a/c setting). When turned to something
>>other than high the code ER appears in the LED where the temp would
>>normally be.
>
>
> ER=error, the AC system has thrown an error code.
>
> On the manual version that is caused by a blown resistor pack, but on
> the automatic system it's a power module and relay combination that is
> located by the blower motor. (don't remember exactly where, but if
> you follow the blower wires you will find it.)
> The power module controls lower speeds and the relay runs the high
> speed. So if it's on high then your relay is ok, but the power module
> is probably toast.
>
> When the ER pops up, press either A/C or Recirc and the codes should
> scroll by.
>
> I've got some data on the earlier system but nothing specific for your
> year. 93 should be the same as 95 for the ATC system.
>
On the '95
If you don't see codes by pressing either A/C or RECIRC, [you will also
see the little stickman if that works] go to diag mode.
Press both A/C and RECIRC and hold down. Turn the ATC **** one click
clockwise. All the segments in the display come on.
Let go of A/C and RECIRC and you should see 00 in the display with no
stickman.
Push either A/C or RECIRC once. You should see the stickman again.
Write down the fault codes you see at this point. 25 or 29 means the
ATC module is toast and the rest of the codes may be gibberish.
From there, you can check a few of the major circuits. Just turn the
ATC **** until you see a number, then push the A/C button and record the
value displayed. Caution, the tests are mixed with read input value and
test output circuit all jumbled together.
Test I/O Subsystem Values
01 In Blower A/D OC, SC, or 00-255 or ?
02 In Blower Feedback ? or 00-255
03 Out 00-255 sets blower speed
04 Out Blower High 00=off 01= set blower high relay on.
Those would be the main ones. My guess is similar to Doug's, the blower
control is toast. The relay is enough to get high speed only. If you
ever smelled magic smoke, the controller probably shorted out, otherwise
is either open or the input from the ATC panel isn't getting to it.
Guest
Posts: n/a
Re: Jeep GC 95 Climate Control Code Problem
Lon did pass the time by typing:
> On the '95
> If you don't see codes by pressing either A/C or RECIRC, [you will also
> see the little stickman if that works] go to diag mode.
>
> Press both A/C and RECIRC and hold down. Turn the ATC **** one click
> clockwise. All the segments in the display come on.
>
> Let go of A/C and RECIRC and you should see 00 in the display with no
> stickman.
>
> Push either A/C or RECIRC once. You should see the stickman again.
> Write down the fault codes you see at this point. 25 or 29 means the
> ATC module is toast and the rest of the codes may be gibberish.
>
> From there, you can check a few of the major circuits. Just turn the
> ATC **** until you see a number, then push the A/C button and record the
> value displayed. Caution, the tests are mixed with read input value and
> test output circuit all jumbled together.
>
> Test I/O Subsystem Values
>
> 01 In Blower A/D OC, SC, or 00-255 or ?
> 02 In Blower Feedback ? or 00-255
> 03 Out 00-255 sets blower speed
> 04 Out Blower High 00=off 01= set blower high relay on.
Interesting, that is the same procedure in my book for the 93
Guess the system didn't change much till 96.
--
DougW
> On the '95
> If you don't see codes by pressing either A/C or RECIRC, [you will also
> see the little stickman if that works] go to diag mode.
>
> Press both A/C and RECIRC and hold down. Turn the ATC **** one click
> clockwise. All the segments in the display come on.
>
> Let go of A/C and RECIRC and you should see 00 in the display with no
> stickman.
>
> Push either A/C or RECIRC once. You should see the stickman again.
> Write down the fault codes you see at this point. 25 or 29 means the
> ATC module is toast and the rest of the codes may be gibberish.
>
> From there, you can check a few of the major circuits. Just turn the
> ATC **** until you see a number, then push the A/C button and record the
> value displayed. Caution, the tests are mixed with read input value and
> test output circuit all jumbled together.
>
> Test I/O Subsystem Values
>
> 01 In Blower A/D OC, SC, or 00-255 or ?
> 02 In Blower Feedback ? or 00-255
> 03 Out 00-255 sets blower speed
> 04 Out Blower High 00=off 01= set blower high relay on.
Interesting, that is the same procedure in my book for the 93
Guess the system didn't change much till 96.
--
DougW
Guest
Posts: n/a
Re: Jeep GC 95 Climate Control Code Problem
Lon did pass the time by typing:
> On the '95
> If you don't see codes by pressing either A/C or RECIRC, [you will also
> see the little stickman if that works] go to diag mode.
>
> Press both A/C and RECIRC and hold down. Turn the ATC **** one click
> clockwise. All the segments in the display come on.
>
> Let go of A/C and RECIRC and you should see 00 in the display with no
> stickman.
>
> Push either A/C or RECIRC once. You should see the stickman again.
> Write down the fault codes you see at this point. 25 or 29 means the
> ATC module is toast and the rest of the codes may be gibberish.
>
> From there, you can check a few of the major circuits. Just turn the
> ATC **** until you see a number, then push the A/C button and record the
> value displayed. Caution, the tests are mixed with read input value and
> test output circuit all jumbled together.
>
> Test I/O Subsystem Values
>
> 01 In Blower A/D OC, SC, or 00-255 or ?
> 02 In Blower Feedback ? or 00-255
> 03 Out 00-255 sets blower speed
> 04 Out Blower High 00=off 01= set blower high relay on.
Interesting, that is the same procedure in my book for the 93
Guess the system didn't change much till 96.
--
DougW
> On the '95
> If you don't see codes by pressing either A/C or RECIRC, [you will also
> see the little stickman if that works] go to diag mode.
>
> Press both A/C and RECIRC and hold down. Turn the ATC **** one click
> clockwise. All the segments in the display come on.
>
> Let go of A/C and RECIRC and you should see 00 in the display with no
> stickman.
>
> Push either A/C or RECIRC once. You should see the stickman again.
> Write down the fault codes you see at this point. 25 or 29 means the
> ATC module is toast and the rest of the codes may be gibberish.
>
> From there, you can check a few of the major circuits. Just turn the
> ATC **** until you see a number, then push the A/C button and record the
> value displayed. Caution, the tests are mixed with read input value and
> test output circuit all jumbled together.
>
> Test I/O Subsystem Values
>
> 01 In Blower A/D OC, SC, or 00-255 or ?
> 02 In Blower Feedback ? or 00-255
> 03 Out 00-255 sets blower speed
> 04 Out Blower High 00=off 01= set blower high relay on.
Interesting, that is the same procedure in my book for the 93
Guess the system didn't change much till 96.
--
DougW
Guest
Posts: n/a
Re: Jeep GC 95 Climate Control Code Problem
Lon did pass the time by typing:
> On the '95
> If you don't see codes by pressing either A/C or RECIRC, [you will also
> see the little stickman if that works] go to diag mode.
>
> Press both A/C and RECIRC and hold down. Turn the ATC **** one click
> clockwise. All the segments in the display come on.
>
> Let go of A/C and RECIRC and you should see 00 in the display with no
> stickman.
>
> Push either A/C or RECIRC once. You should see the stickman again.
> Write down the fault codes you see at this point. 25 or 29 means the
> ATC module is toast and the rest of the codes may be gibberish.
>
> From there, you can check a few of the major circuits. Just turn the
> ATC **** until you see a number, then push the A/C button and record the
> value displayed. Caution, the tests are mixed with read input value and
> test output circuit all jumbled together.
>
> Test I/O Subsystem Values
>
> 01 In Blower A/D OC, SC, or 00-255 or ?
> 02 In Blower Feedback ? or 00-255
> 03 Out 00-255 sets blower speed
> 04 Out Blower High 00=off 01= set blower high relay on.
Interesting, that is the same procedure in my book for the 93
Guess the system didn't change much till 96.
--
DougW
> On the '95
> If you don't see codes by pressing either A/C or RECIRC, [you will also
> see the little stickman if that works] go to diag mode.
>
> Press both A/C and RECIRC and hold down. Turn the ATC **** one click
> clockwise. All the segments in the display come on.
>
> Let go of A/C and RECIRC and you should see 00 in the display with no
> stickman.
>
> Push either A/C or RECIRC once. You should see the stickman again.
> Write down the fault codes you see at this point. 25 or 29 means the
> ATC module is toast and the rest of the codes may be gibberish.
>
> From there, you can check a few of the major circuits. Just turn the
> ATC **** until you see a number, then push the A/C button and record the
> value displayed. Caution, the tests are mixed with read input value and
> test output circuit all jumbled together.
>
> Test I/O Subsystem Values
>
> 01 In Blower A/D OC, SC, or 00-255 or ?
> 02 In Blower Feedback ? or 00-255
> 03 Out 00-255 sets blower speed
> 04 Out Blower High 00=off 01= set blower high relay on.
Interesting, that is the same procedure in my book for the 93
Guess the system didn't change much till 96.
--
DougW