ECU for Jeep Cherokee
#31
Guest
Posts: n/a
Re: ECU for Jeep Cherokee
It is an automatic transmission. What is the wiper return voltage? The other
voltage I can measure on the TPS besides the ~200mV to ~4V?
I check the message with an OBD Reader. P0123 I think is the number or
P0124, don't remember right now. Are you referring to the Check Engine Light
flashing when you mension a 24 and a 15?
"Stephen Cowell" <scowell@sbcglobal.net> wrote in message
news:22pre.430$kX4.116@newssvr30.news.prodigy.com. ..
"reigelser" <reigelser@sbcglobal.net> wrote in message
news:m7ore.757$aa2.19@newssvr17.news.prodigy.com.. .
> I need the ECU eventually because of a persistent TPS error. My mechanic
> troubleshooted it and thinks its probably the ECU. But he thinks there has
> to be some reprogramming to be done, because I tried one from the junk
> yard
> before he looked into it and nothing changed (same TPS error, same
> mileage).
> It's a 97 inline 6 Cherokee. It works, but it doesn't start at first try
> and
> it is not very smooth if you want to accelerate from 65 to 75 without a
> kickdown.
So it only throws a 24 code? Do you have a manual
or automatic transmission? Any aftermarket parts
on the engine? It's never thrown a 15 (VSS)? That
causes kickdown problems too...
With the TPS, you can actually patch a digital
voltmeter in and watch the voltage as you drive...
won't hurt a thing. If the computer's bad, then
you'd expect the +V to the TPS to fluctuate...
if the TPS is bad, you'd expect the wiper return
voltage to be wrong for the rpm, gear, etc.
That's what I'd do next...
__
Steve
..
voltage I can measure on the TPS besides the ~200mV to ~4V?
I check the message with an OBD Reader. P0123 I think is the number or
P0124, don't remember right now. Are you referring to the Check Engine Light
flashing when you mension a 24 and a 15?
"Stephen Cowell" <scowell@sbcglobal.net> wrote in message
news:22pre.430$kX4.116@newssvr30.news.prodigy.com. ..
"reigelser" <reigelser@sbcglobal.net> wrote in message
news:m7ore.757$aa2.19@newssvr17.news.prodigy.com.. .
> I need the ECU eventually because of a persistent TPS error. My mechanic
> troubleshooted it and thinks its probably the ECU. But he thinks there has
> to be some reprogramming to be done, because I tried one from the junk
> yard
> before he looked into it and nothing changed (same TPS error, same
> mileage).
> It's a 97 inline 6 Cherokee. It works, but it doesn't start at first try
> and
> it is not very smooth if you want to accelerate from 65 to 75 without a
> kickdown.
So it only throws a 24 code? Do you have a manual
or automatic transmission? Any aftermarket parts
on the engine? It's never thrown a 15 (VSS)? That
causes kickdown problems too...
With the TPS, you can actually patch a digital
voltmeter in and watch the voltage as you drive...
won't hurt a thing. If the computer's bad, then
you'd expect the +V to the TPS to fluctuate...
if the TPS is bad, you'd expect the wiper return
voltage to be wrong for the rpm, gear, etc.
That's what I'd do next...
__
Steve
..
#32
Guest
Posts: n/a
Re: ECU for Jeep Cherokee
It is an automatic transmission. What is the wiper return voltage? The other
voltage I can measure on the TPS besides the ~200mV to ~4V?
I check the message with an OBD Reader. P0123 I think is the number or
P0124, don't remember right now. Are you referring to the Check Engine Light
flashing when you mension a 24 and a 15?
"Stephen Cowell" <scowell@sbcglobal.net> wrote in message
news:22pre.430$kX4.116@newssvr30.news.prodigy.com. ..
"reigelser" <reigelser@sbcglobal.net> wrote in message
news:m7ore.757$aa2.19@newssvr17.news.prodigy.com.. .
> I need the ECU eventually because of a persistent TPS error. My mechanic
> troubleshooted it and thinks its probably the ECU. But he thinks there has
> to be some reprogramming to be done, because I tried one from the junk
> yard
> before he looked into it and nothing changed (same TPS error, same
> mileage).
> It's a 97 inline 6 Cherokee. It works, but it doesn't start at first try
> and
> it is not very smooth if you want to accelerate from 65 to 75 without a
> kickdown.
So it only throws a 24 code? Do you have a manual
or automatic transmission? Any aftermarket parts
on the engine? It's never thrown a 15 (VSS)? That
causes kickdown problems too...
With the TPS, you can actually patch a digital
voltmeter in and watch the voltage as you drive...
won't hurt a thing. If the computer's bad, then
you'd expect the +V to the TPS to fluctuate...
if the TPS is bad, you'd expect the wiper return
voltage to be wrong for the rpm, gear, etc.
That's what I'd do next...
__
Steve
..
voltage I can measure on the TPS besides the ~200mV to ~4V?
I check the message with an OBD Reader. P0123 I think is the number or
P0124, don't remember right now. Are you referring to the Check Engine Light
flashing when you mension a 24 and a 15?
"Stephen Cowell" <scowell@sbcglobal.net> wrote in message
news:22pre.430$kX4.116@newssvr30.news.prodigy.com. ..
"reigelser" <reigelser@sbcglobal.net> wrote in message
news:m7ore.757$aa2.19@newssvr17.news.prodigy.com.. .
> I need the ECU eventually because of a persistent TPS error. My mechanic
> troubleshooted it and thinks its probably the ECU. But he thinks there has
> to be some reprogramming to be done, because I tried one from the junk
> yard
> before he looked into it and nothing changed (same TPS error, same
> mileage).
> It's a 97 inline 6 Cherokee. It works, but it doesn't start at first try
> and
> it is not very smooth if you want to accelerate from 65 to 75 without a
> kickdown.
So it only throws a 24 code? Do you have a manual
or automatic transmission? Any aftermarket parts
on the engine? It's never thrown a 15 (VSS)? That
causes kickdown problems too...
With the TPS, you can actually patch a digital
voltmeter in and watch the voltage as you drive...
won't hurt a thing. If the computer's bad, then
you'd expect the +V to the TPS to fluctuate...
if the TPS is bad, you'd expect the wiper return
voltage to be wrong for the rpm, gear, etc.
That's what I'd do next...
__
Steve
..
#33
Guest
Posts: n/a
Re: ECU for Jeep Cherokee
It is an automatic transmission. What is the wiper return voltage? The other
voltage I can measure on the TPS besides the ~200mV to ~4V?
I check the message with an OBD Reader. P0123 I think is the number or
P0124, don't remember right now. Are you referring to the Check Engine Light
flashing when you mension a 24 and a 15?
"Stephen Cowell" <scowell@sbcglobal.net> wrote in message
news:22pre.430$kX4.116@newssvr30.news.prodigy.com. ..
"reigelser" <reigelser@sbcglobal.net> wrote in message
news:m7ore.757$aa2.19@newssvr17.news.prodigy.com.. .
> I need the ECU eventually because of a persistent TPS error. My mechanic
> troubleshooted it and thinks its probably the ECU. But he thinks there has
> to be some reprogramming to be done, because I tried one from the junk
> yard
> before he looked into it and nothing changed (same TPS error, same
> mileage).
> It's a 97 inline 6 Cherokee. It works, but it doesn't start at first try
> and
> it is not very smooth if you want to accelerate from 65 to 75 without a
> kickdown.
So it only throws a 24 code? Do you have a manual
or automatic transmission? Any aftermarket parts
on the engine? It's never thrown a 15 (VSS)? That
causes kickdown problems too...
With the TPS, you can actually patch a digital
voltmeter in and watch the voltage as you drive...
won't hurt a thing. If the computer's bad, then
you'd expect the +V to the TPS to fluctuate...
if the TPS is bad, you'd expect the wiper return
voltage to be wrong for the rpm, gear, etc.
That's what I'd do next...
__
Steve
..
voltage I can measure on the TPS besides the ~200mV to ~4V?
I check the message with an OBD Reader. P0123 I think is the number or
P0124, don't remember right now. Are you referring to the Check Engine Light
flashing when you mension a 24 and a 15?
"Stephen Cowell" <scowell@sbcglobal.net> wrote in message
news:22pre.430$kX4.116@newssvr30.news.prodigy.com. ..
"reigelser" <reigelser@sbcglobal.net> wrote in message
news:m7ore.757$aa2.19@newssvr17.news.prodigy.com.. .
> I need the ECU eventually because of a persistent TPS error. My mechanic
> troubleshooted it and thinks its probably the ECU. But he thinks there has
> to be some reprogramming to be done, because I tried one from the junk
> yard
> before he looked into it and nothing changed (same TPS error, same
> mileage).
> It's a 97 inline 6 Cherokee. It works, but it doesn't start at first try
> and
> it is not very smooth if you want to accelerate from 65 to 75 without a
> kickdown.
So it only throws a 24 code? Do you have a manual
or automatic transmission? Any aftermarket parts
on the engine? It's never thrown a 15 (VSS)? That
causes kickdown problems too...
With the TPS, you can actually patch a digital
voltmeter in and watch the voltage as you drive...
won't hurt a thing. If the computer's bad, then
you'd expect the +V to the TPS to fluctuate...
if the TPS is bad, you'd expect the wiper return
voltage to be wrong for the rpm, gear, etc.
That's what I'd do next...
__
Steve
..
#34
Guest
Posts: n/a
Re: ECU for Jeep Cherokee
reigelser did pass the time by typing:
> I need the ECU eventually because of a persistent TPS error. My mechanic
> troubleshooted it and thinks its probably the ECU. But he thinks there has
> to be some reprogramming to be done, because I tried one from the junk yard
> before he looked into it and nothing changed (same TPS error, same mileage).
> It's a 97 inline 6 Cherokee. It works, but it doesn't start at first try and
> it is not very smooth if you want to accelerate from 65 to 75 without a
> kickdown.
Clean the connectors at both the TPS and the ECU.
And while you have the plugs off, ohm out the sensor
lines as the TPS shares a common ground link with
other sensors and that link can go wonky.
All I have is the 93 schematic so you need the color codes for
your year.
--
DougW
> I need the ECU eventually because of a persistent TPS error. My mechanic
> troubleshooted it and thinks its probably the ECU. But he thinks there has
> to be some reprogramming to be done, because I tried one from the junk yard
> before he looked into it and nothing changed (same TPS error, same mileage).
> It's a 97 inline 6 Cherokee. It works, but it doesn't start at first try and
> it is not very smooth if you want to accelerate from 65 to 75 without a
> kickdown.
Clean the connectors at both the TPS and the ECU.
And while you have the plugs off, ohm out the sensor
lines as the TPS shares a common ground link with
other sensors and that link can go wonky.
All I have is the 93 schematic so you need the color codes for
your year.
--
DougW
#35
Guest
Posts: n/a
Re: ECU for Jeep Cherokee
reigelser did pass the time by typing:
> I need the ECU eventually because of a persistent TPS error. My mechanic
> troubleshooted it and thinks its probably the ECU. But he thinks there has
> to be some reprogramming to be done, because I tried one from the junk yard
> before he looked into it and nothing changed (same TPS error, same mileage).
> It's a 97 inline 6 Cherokee. It works, but it doesn't start at first try and
> it is not very smooth if you want to accelerate from 65 to 75 without a
> kickdown.
Clean the connectors at both the TPS and the ECU.
And while you have the plugs off, ohm out the sensor
lines as the TPS shares a common ground link with
other sensors and that link can go wonky.
All I have is the 93 schematic so you need the color codes for
your year.
--
DougW
> I need the ECU eventually because of a persistent TPS error. My mechanic
> troubleshooted it and thinks its probably the ECU. But he thinks there has
> to be some reprogramming to be done, because I tried one from the junk yard
> before he looked into it and nothing changed (same TPS error, same mileage).
> It's a 97 inline 6 Cherokee. It works, but it doesn't start at first try and
> it is not very smooth if you want to accelerate from 65 to 75 without a
> kickdown.
Clean the connectors at both the TPS and the ECU.
And while you have the plugs off, ohm out the sensor
lines as the TPS shares a common ground link with
other sensors and that link can go wonky.
All I have is the 93 schematic so you need the color codes for
your year.
--
DougW
#36
Guest
Posts: n/a
Re: ECU for Jeep Cherokee
reigelser did pass the time by typing:
> I need the ECU eventually because of a persistent TPS error. My mechanic
> troubleshooted it and thinks its probably the ECU. But he thinks there has
> to be some reprogramming to be done, because I tried one from the junk yard
> before he looked into it and nothing changed (same TPS error, same mileage).
> It's a 97 inline 6 Cherokee. It works, but it doesn't start at first try and
> it is not very smooth if you want to accelerate from 65 to 75 without a
> kickdown.
Clean the connectors at both the TPS and the ECU.
And while you have the plugs off, ohm out the sensor
lines as the TPS shares a common ground link with
other sensors and that link can go wonky.
All I have is the 93 schematic so you need the color codes for
your year.
--
DougW
> I need the ECU eventually because of a persistent TPS error. My mechanic
> troubleshooted it and thinks its probably the ECU. But he thinks there has
> to be some reprogramming to be done, because I tried one from the junk yard
> before he looked into it and nothing changed (same TPS error, same mileage).
> It's a 97 inline 6 Cherokee. It works, but it doesn't start at first try and
> it is not very smooth if you want to accelerate from 65 to 75 without a
> kickdown.
Clean the connectors at both the TPS and the ECU.
And while you have the plugs off, ohm out the sensor
lines as the TPS shares a common ground link with
other sensors and that link can go wonky.
All I have is the 93 schematic so you need the color codes for
your year.
--
DougW
#37
Guest
Posts: n/a
Re: ECU for Jeep Cherokee
reigelser did pass the time by typing:
> I need the ECU eventually because of a persistent TPS error. My mechanic
> troubleshooted it and thinks its probably the ECU. But he thinks there has
> to be some reprogramming to be done, because I tried one from the junk yard
> before he looked into it and nothing changed (same TPS error, same mileage).
> It's a 97 inline 6 Cherokee. It works, but it doesn't start at first try and
> it is not very smooth if you want to accelerate from 65 to 75 without a
> kickdown.
Clean the connectors at both the TPS and the ECU.
And while you have the plugs off, ohm out the sensor
lines as the TPS shares a common ground link with
other sensors and that link can go wonky.
All I have is the 93 schematic so you need the color codes for
your year.
--
DougW
> I need the ECU eventually because of a persistent TPS error. My mechanic
> troubleshooted it and thinks its probably the ECU. But he thinks there has
> to be some reprogramming to be done, because I tried one from the junk yard
> before he looked into it and nothing changed (same TPS error, same mileage).
> It's a 97 inline 6 Cherokee. It works, but it doesn't start at first try and
> it is not very smooth if you want to accelerate from 65 to 75 without a
> kickdown.
Clean the connectors at both the TPS and the ECU.
And while you have the plugs off, ohm out the sensor
lines as the TPS shares a common ground link with
other sensors and that link can go wonky.
All I have is the 93 schematic so you need the color codes for
your year.
--
DougW
#38
Guest
Posts: n/a
Re: ECU for Jeep Cherokee
"reigelser" <reigelser@sbcglobal.net> wrote in message news:Dipre.429$on5.195@newssvr19.news.prodigy.com. ..
> It is an automatic transmission. What is the wiper return voltage? The other
> voltage I can measure on the TPS besides the ~200mV to ~4V?
> I check the message with an OBD Reader. P0123 I think is the number or
> P0124, don't remember right now. Are you referring to the Check Engine Light
> flashing when you mension a 24 and a 15?
Yes... too cheap to get the OBD. '124' would correspond to
the '24'... TPS.
Start thinking about things like the ground wire
between the engine and the firewall.. this is a
known problem point. Doug has the right
idea... make sure all connections are clean
and tight.
Problem starting... to start an EFI vehicle, you
should keep your foot *off* the gas until the
vehicle has started... no need to touch the
gas until you take off. You're doing this,
right?
Has other maintenance been done recently?
Does the engine run smooth once it starts?
Describe what you have to do to get it
to start (i.e. grind long, grind twice, feather
throttle, etc.).
The TPS is basically a potentiometer, with three
wires going to it... supply, wiper, and ground. The supply
is a regulated voltage, sent by the computer and used
by the computer as a reference. If this is moving around,
the computer may have unfixable problems (blown regulator
pass transistor, etc.) or another sensor or connection may be
screwing up your TPS reading. The wiper voltage is the one that
changes as the throttle plate opens and closes... it should
track the position of the gas pedal steadily. The wiper
carries your 200mV to 4V.
__
Steve
..
#39
Guest
Posts: n/a
Re: ECU for Jeep Cherokee
"reigelser" <reigelser@sbcglobal.net> wrote in message news:Dipre.429$on5.195@newssvr19.news.prodigy.com. ..
> It is an automatic transmission. What is the wiper return voltage? The other
> voltage I can measure on the TPS besides the ~200mV to ~4V?
> I check the message with an OBD Reader. P0123 I think is the number or
> P0124, don't remember right now. Are you referring to the Check Engine Light
> flashing when you mension a 24 and a 15?
Yes... too cheap to get the OBD. '124' would correspond to
the '24'... TPS.
Start thinking about things like the ground wire
between the engine and the firewall.. this is a
known problem point. Doug has the right
idea... make sure all connections are clean
and tight.
Problem starting... to start an EFI vehicle, you
should keep your foot *off* the gas until the
vehicle has started... no need to touch the
gas until you take off. You're doing this,
right?
Has other maintenance been done recently?
Does the engine run smooth once it starts?
Describe what you have to do to get it
to start (i.e. grind long, grind twice, feather
throttle, etc.).
The TPS is basically a potentiometer, with three
wires going to it... supply, wiper, and ground. The supply
is a regulated voltage, sent by the computer and used
by the computer as a reference. If this is moving around,
the computer may have unfixable problems (blown regulator
pass transistor, etc.) or another sensor or connection may be
screwing up your TPS reading. The wiper voltage is the one that
changes as the throttle plate opens and closes... it should
track the position of the gas pedal steadily. The wiper
carries your 200mV to 4V.
__
Steve
..
#40
Guest
Posts: n/a
Re: ECU for Jeep Cherokee
"reigelser" <reigelser@sbcglobal.net> wrote in message news:Dipre.429$on5.195@newssvr19.news.prodigy.com. ..
> It is an automatic transmission. What is the wiper return voltage? The other
> voltage I can measure on the TPS besides the ~200mV to ~4V?
> I check the message with an OBD Reader. P0123 I think is the number or
> P0124, don't remember right now. Are you referring to the Check Engine Light
> flashing when you mension a 24 and a 15?
Yes... too cheap to get the OBD. '124' would correspond to
the '24'... TPS.
Start thinking about things like the ground wire
between the engine and the firewall.. this is a
known problem point. Doug has the right
idea... make sure all connections are clean
and tight.
Problem starting... to start an EFI vehicle, you
should keep your foot *off* the gas until the
vehicle has started... no need to touch the
gas until you take off. You're doing this,
right?
Has other maintenance been done recently?
Does the engine run smooth once it starts?
Describe what you have to do to get it
to start (i.e. grind long, grind twice, feather
throttle, etc.).
The TPS is basically a potentiometer, with three
wires going to it... supply, wiper, and ground. The supply
is a regulated voltage, sent by the computer and used
by the computer as a reference. If this is moving around,
the computer may have unfixable problems (blown regulator
pass transistor, etc.) or another sensor or connection may be
screwing up your TPS reading. The wiper voltage is the one that
changes as the throttle plate opens and closes... it should
track the position of the gas pedal steadily. The wiper
carries your 200mV to 4V.
__
Steve
..