M Lee

I was driving my 1996 Larado GC 6 cyl in town yesterday when the "Check
Engine Light" came on and the engine suddenly began running very rough
and stalling. I managed to get home but the jeep is hurtin' :(.

Per my Haynes manual I used the on/off on/off on/off ignition key
routine to generate the error code(s) but the resulting multiple error
codes left me scratching my head. Could someone help me interpret the
following?

Code 12 - Problem with battery connection. Direct battery input to
controller disconnected within the last 50 ignition key-ons.

The battery has not been disconnected so this is a mystery.

Code 14 - MAP sensor circuit open or shorted; voltage too low

What and where is the "MAP sensor circuit" and how may I test it?

Code 34 - Speed control vacuum or vent solenoid circuits open or shorted.

Where are the Speed control vacuum and vent solenoid and how may I
test them?

Code 43 - Peak primary coil current not achieved with max dwell time
OR
Cylinder misfire
OR
Problem in power module to logic module interface

This may have simply been generated because the cylinders were
misfiring quite frequently while the car war running.

Code 77 - The Haynes manual does not indicate the meaning of this error
code.

Could anyone tell me what this code means?

Code 55 - According to Haynes this code simply means that the computer
has finished displaying all the codes.


I'm reduced to riding my bicycle in the Florida heat so any help would
be greatly appreciated.


Best Regards,

Marcel

DougW

M Lee did pass the time by typing:
> I was driving my 1996 Larado GC 6 cyl in town yesterday when the "Check
> Engine Light" came on and the engine suddenly began running very rough
> and stalling. I managed to get home but the jeep is hurtin' :(.
>
> Per my Haynes manual I used the on/off on/off on/off ignition key
> routine to generate the error code(s) but the resulting multiple error
> codes left me scratching my head. Could someone help me interpret the
> following?

> Code 77 - The Haynes manual does not indicate the meaning of this error
> code.

77 - Malfunction detected with power feed to speed control servo solenoids.

... before doing anything else ..

check your battery terminals and make sure they arn't loose
and the connections between the battery ground and chassis,
ignition coil and chassis are both good.

... ..

12 is a common fault code, in combination with other fault codes like
you show it's also an indication that the battery terminal connection
is loose.

All those other codes can be thrown by misfire.

Also check the plug wires and the wire to the coil to make
sure nothing has come loose.

Disconnect and reconnect the MAP sensor connector. It's on the firewall
just back of the intake rail.

Sensors and locations here.
http://revbeergoggles.com/Fixes/diagnostics.html

--
DougW

DougW

M Lee did pass the time by typing:
> I was driving my 1996 Larado GC 6 cyl in town yesterday when the "Check
> Engine Light" came on and the engine suddenly began running very rough
> and stalling. I managed to get home but the jeep is hurtin' :(.
>
> Per my Haynes manual I used the on/off on/off on/off ignition key
> routine to generate the error code(s) but the resulting multiple error
> codes left me scratching my head. Could someone help me interpret the
> following?

> Code 77 - The Haynes manual does not indicate the meaning of this error
> code.

77 - Malfunction detected with power feed to speed control servo solenoids.

... before doing anything else ..

check your battery terminals and make sure they arn't loose
and the connections between the battery ground and chassis,
ignition coil and chassis are both good.

... ..

12 is a common fault code, in combination with other fault codes like
you show it's also an indication that the battery terminal connection
is loose.

All those other codes can be thrown by misfire.

Also check the plug wires and the wire to the coil to make
sure nothing has come loose.

Disconnect and reconnect the MAP sensor connector. It's on the firewall
just back of the intake rail.

Sensors and locations here.
http://revbeergoggles.com/Fixes/diagnostics.html

--
DougW

DougW

M Lee did pass the time by typing:
> I was driving my 1996 Larado GC 6 cyl in town yesterday when the "Check
> Engine Light" came on and the engine suddenly began running very rough
> and stalling. I managed to get home but the jeep is hurtin' :(.
>
> Per my Haynes manual I used the on/off on/off on/off ignition key
> routine to generate the error code(s) but the resulting multiple error
> codes left me scratching my head. Could someone help me interpret the
> following?

> Code 77 - The Haynes manual does not indicate the meaning of this error
> code.

77 - Malfunction detected with power feed to speed control servo solenoids.

... before doing anything else ..

check your battery terminals and make sure they arn't loose
and the connections between the battery ground and chassis,
ignition coil and chassis are both good.

... ..

12 is a common fault code, in combination with other fault codes like
you show it's also an indication that the battery terminal connection
is loose.

All those other codes can be thrown by misfire.

Also check the plug wires and the wire to the coil to make
sure nothing has come loose.

Disconnect and reconnect the MAP sensor connector. It's on the firewall
just back of the intake rail.

Sensors and locations here.
http://revbeergoggles.com/Fixes/diagnostics.html

--
DougW

DougW

M Lee did pass the time by typing:
> I was driving my 1996 Larado GC 6 cyl in town yesterday when the "Check
> Engine Light" came on and the engine suddenly began running very rough
> and stalling. I managed to get home but the jeep is hurtin' :(.
>
> Per my Haynes manual I used the on/off on/off on/off ignition key
> routine to generate the error code(s) but the resulting multiple error
> codes left me scratching my head. Could someone help me interpret the
> following?

> Code 77 - The Haynes manual does not indicate the meaning of this error
> code.

77 - Malfunction detected with power feed to speed control servo solenoids.

... before doing anything else ..

check your battery terminals and make sure they arn't loose
and the connections between the battery ground and chassis,
ignition coil and chassis are both good.

... ..

12 is a common fault code, in combination with other fault codes like
you show it's also an indication that the battery terminal connection
is loose.

All those other codes can be thrown by misfire.

Also check the plug wires and the wire to the coil to make
sure nothing has come loose.

Disconnect and reconnect the MAP sensor connector. It's on the firewall
just back of the intake rail.

Sensors and locations here.
http://revbeergoggles.com/Fixes/diagnostics.html

--
DougW

tim bur

77 is fuel system lean and the rest might come from stalling
43 is cylinder misfire on that year jeep might have a melted harness issue based on the first
2 codes wityh voltage high

M Lee wrote:

> I was driving my 1996 Larado GC 6 cyl in town yesterday when the "Check
> Engine Light" came on and the engine suddenly began running very rough
> and stalling. I managed to get home but the jeep is hurtin' :(.
>
> Per my Haynes manual I used the on/off on/off on/off ignition key
> routine to generate the error code(s) but the resulting multiple error
> codes left me scratching my head. Could someone help me interpret the
> following?
>
> Code 12 - Problem with battery connection. Direct battery input to
> controller disconnected within the last 50 ignition key-ons.
>
> The battery has not been disconnected so this is a mystery.
>
> Code 14 - MAP sensor circuit open or shorted; voltage too low
>
> What and where is the "MAP sensor circuit" and how may I test it?
>
> Code 34 - Speed control vacuum or vent solenoid circuits open or shorted.
>
> Where are the Speed control vacuum and vent solenoid and how may I
> test them?
>
> Code 43 - Peak primary coil current not achieved with max dwell time
> OR
> Cylinder misfire
> OR
> Problem in power module to logic module interface
>
> This may have simply been generated because the cylinders were
> misfiring quite frequently while the car war running.
>
> Code 77 - The Haynes manual does not indicate the meaning of this error
> code.
>
> Could anyone tell me what this code means?
>
> Code 55 - According to Haynes this code simply means that the computer
> has finished displaying all the codes.
>
> I'm reduced to riding my bicycle in the Florida heat so any help would
> be greatly appreciated.
>
> Best Regards,
>
> Marcel

tim bur

77 is fuel system lean and the rest might come from stalling
43 is cylinder misfire on that year jeep might have a melted harness issue based on the first
2 codes wityh voltage high

M Lee wrote:

> I was driving my 1996 Larado GC 6 cyl in town yesterday when the "Check
> Engine Light" came on and the engine suddenly began running very rough
> and stalling. I managed to get home but the jeep is hurtin' :(.
>
> Per my Haynes manual I used the on/off on/off on/off ignition key
> routine to generate the error code(s) but the resulting multiple error
> codes left me scratching my head. Could someone help me interpret the
> following?
>
> Code 12 - Problem with battery connection. Direct battery input to
> controller disconnected within the last 50 ignition key-ons.
>
> The battery has not been disconnected so this is a mystery.
>
> Code 14 - MAP sensor circuit open or shorted; voltage too low
>
> What and where is the "MAP sensor circuit" and how may I test it?
>
> Code 34 - Speed control vacuum or vent solenoid circuits open or shorted.
>
> Where are the Speed control vacuum and vent solenoid and how may I
> test them?
>
> Code 43 - Peak primary coil current not achieved with max dwell time
> OR
> Cylinder misfire
> OR
> Problem in power module to logic module interface
>
> This may have simply been generated because the cylinders were
> misfiring quite frequently while the car war running.
>
> Code 77 - The Haynes manual does not indicate the meaning of this error
> code.
>
> Could anyone tell me what this code means?
>
> Code 55 - According to Haynes this code simply means that the computer
> has finished displaying all the codes.
>
> I'm reduced to riding my bicycle in the Florida heat so any help would
> be greatly appreciated.
>
> Best Regards,
>
> Marcel

tim bur

77 is fuel system lean and the rest might come from stalling
43 is cylinder misfire on that year jeep might have a melted harness issue based on the first
2 codes wityh voltage high

M Lee wrote:

> I was driving my 1996 Larado GC 6 cyl in town yesterday when the "Check
> Engine Light" came on and the engine suddenly began running very rough
> and stalling. I managed to get home but the jeep is hurtin' :(.
>
> Per my Haynes manual I used the on/off on/off on/off ignition key
> routine to generate the error code(s) but the resulting multiple error
> codes left me scratching my head. Could someone help me interpret the
> following?
>
> Code 12 - Problem with battery connection. Direct battery input to
> controller disconnected within the last 50 ignition key-ons.
>
> The battery has not been disconnected so this is a mystery.
>
> Code 14 - MAP sensor circuit open or shorted; voltage too low
>
> What and where is the "MAP sensor circuit" and how may I test it?
>
> Code 34 - Speed control vacuum or vent solenoid circuits open or shorted.
>
> Where are the Speed control vacuum and vent solenoid and how may I
> test them?
>
> Code 43 - Peak primary coil current not achieved with max dwell time
> OR
> Cylinder misfire
> OR
> Problem in power module to logic module interface
>
> This may have simply been generated because the cylinders were
> misfiring quite frequently while the car war running.
>
> Code 77 - The Haynes manual does not indicate the meaning of this error
> code.
>
> Could anyone tell me what this code means?
>
> Code 55 - According to Haynes this code simply means that the computer
> has finished displaying all the codes.
>
> I'm reduced to riding my bicycle in the Florida heat so any help would
> be greatly appreciated.
>
> Best Regards,
>
> Marcel

tim bur

77 is fuel system lean and the rest might come from stalling
43 is cylinder misfire on that year jeep might have a melted harness issue based on the first
2 codes wityh voltage high

M Lee wrote:

> I was driving my 1996 Larado GC 6 cyl in town yesterday when the "Check
> Engine Light" came on and the engine suddenly began running very rough
> and stalling. I managed to get home but the jeep is hurtin' :(.
>
> Per my Haynes manual I used the on/off on/off on/off ignition key
> routine to generate the error code(s) but the resulting multiple error
> codes left me scratching my head. Could someone help me interpret the
> following?
>
> Code 12 - Problem with battery connection. Direct battery input to
> controller disconnected within the last 50 ignition key-ons.
>
> The battery has not been disconnected so this is a mystery.
>
> Code 14 - MAP sensor circuit open or shorted; voltage too low
>
> What and where is the "MAP sensor circuit" and how may I test it?
>
> Code 34 - Speed control vacuum or vent solenoid circuits open or shorted.
>
> Where are the Speed control vacuum and vent solenoid and how may I
> test them?
>
> Code 43 - Peak primary coil current not achieved with max dwell time
> OR
> Cylinder misfire
> OR
> Problem in power module to logic module interface
>
> This may have simply been generated because the cylinders were
> misfiring quite frequently while the car war running.
>
> Code 77 - The Haynes manual does not indicate the meaning of this error
> code.
>
> Could anyone tell me what this code means?
>
> Code 55 - According to Haynes this code simply means that the computer
> has finished displaying all the codes.
>
> I'm reduced to riding my bicycle in the Florida heat so any help would
> be greatly appreciated.
>
> Best Regards,
>
> Marcel

M Lee

Thanks for the lightning fast replies!

I reseated the electrical connections as was suggested. The "Check
Engine" went off and the car started and ran smoothly. Cool!

BTW...Over the years, the knowledge and advice gleaned from this
newsgroup has saved this barely competent shade tree mechanic many
hundreds of $$$ in car repair fees.

You guys and gals are awesome and much appreciated!

Best regards,

Marcel