Question about 1994 Jeep Grand Cherokee

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I cant get the pcm to accept my jeeps signal to stay running

  1. i changed the pcm in my 94 grand chrerokee because i was'nt getting a signal to my fuel relay. now i get a signal, but it will shut down as soon as it starts. i don't have an alarm in it from the factory ,but there may be some kind of a security device that it does not recognize. the numbers on the pcm match exactly. is there a way to re-boot the pcm so it will accept my jeeps signals?

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  • jamesldubois Oct 03, 2008

    as it turns out, the automatic shutdown is what was not getting the proper signal. so if i juiced the fuel pump, it would have been the only thing energized in the whole ignition system. i changed the pcm and all is well again. thanks for the input gentlemen . sincerly a broke jeep owner.

  • jamesldubois Oct 03, 2008

    hi yate. i appreciate what you guys do . its a good service for the fix it ourselves kinda people. thanks again. peace dude.

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Hi have you tested to see wheather the live feed is still there when it cuts out if not your engine management module controls all security issues not the pcm if its the same part number then it doesnt need any thing doing to it other than plug it in its a case of two things with it being an older vechicle is it worth spending money on example presuming the pcm good the its a process of elimanation do you want to try the ecm expensive or if this is your only problem by-pass it alltogether by putting a fused live feed from your igntion switch to the relay alot cheaper and won,t make a jot of difference to the preformance yates210456

Posted on Oct 02, 2008

  • paul yates Oct 03, 2008

    hi main thing is your on your way thanks for getting back yates210456

  • paul yates Oct 04, 2008

    my motto is if your prepared to help yourself i am prepared to help best i can its hard enough life without us little people not helping each other best of luck in the future yates210456

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1 Answer

1992 Plymouth Grand Voyager won't start, fuel pump runs for about 1/2 second when you turn on the key


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Which codes (OBDI or II) do I use for my 1994 Jeep Grand cherokee laredo 4.0 2wd


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when you turn on key you need to count check engine light blinks.

here are codes taken from internet.

11* No crank reference signal detected during engine cranking.
12* Direct battery input to PCM was disconnected within the last 50 key-on cycles.
13** No difference recognized between the engine MAP reading and the barometric (atmosphereic) pressure reading at start-up
14** MAP sensor input below minimum acceptable voltage.
or
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15** No vehicle distance (speed) sensor signal detected during road load conditions.
17* Engine coolant temperature remains below normal operating temperatures during vehicle travel (thermostat).
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or
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22** Engine coolant temperature sensor input above maximum acceptable voltage.
or
Engine coolant temperature sensor input below minimum acceptable voltage.
23** Intake manifold air temperature sensor input above maximum acceptable voltage.
or
Intake manifold air temperature sensor input below minimum acceptable voltage.
24** Throttle position sensor input above maximum acceptable voltage.
or
Throttle position sensor input below minimum acceptable voltage.
25** A shorted condition detected in one or more of the idle air control motor circuits.
27* Injector #1 output driver does not respond properly to the control signal.
or
Injector #2 output driver does not respond properly to the control signal.
or
Injector #3 output driver does not respond properly to the control signal.
or
Injector #4 output driver does not respond properly to the control signal.
or
Injector #5 output driver does not respond properly to the control signal.
or
Injector #6 output driver does not respond properly to the control signal.
33* An open or shorted condition detected in the A/C clutch relay circuit.
34* An open or shorted condition detected in the speed control vacuum or vent solenoid circuits.
or
Speed control switch input below the minimum acceptable voltage.
or
Speed control switch input above the maximum acceptable voltage.
35* An open or shorted condition detected in the radiator fan relay circuit.
41* An open or shorted condition detected in the generator field control circuit.
42* An open or shorted condition detected in the auto shutdown relay circuit.
44* An open or shorted condition exists in the engine coolant temperature sensor circuit or a problem exists in the PCM's battery temperature voltage circuit.
46** Battery voltage sense input above target charging voltage during engine operation.
47** Battery voltage sense input below target charging voltage during engine operation. Also, no significant change detected in battery voltage during active test of generator output.
51** Oxygen sensor signal input indicates lean air/fuel ratio condition during engine operation.
52** Oxygen sensor signal input indicates rich air/fuel ratio condition during engine operation.
53* PCM internal fault condition detected.
54* No fuel sync (camshaft signal) detected during engine cranking.
55* Completion of diagnostic trouble code display on the malfunction indicator lamp (check engine lamp).
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63* Unsuccessful attempt to write to an EEPROM location by the PCM.

* - Check engine lamp will not illuminate at all times if this code was recorded. Cycle ignition key as described and observe code flashed by check engine lamp.

** - Check engine lamp will illuminate during engine operation if this code was recorded.

PCM = Powertrain Control Module (the engine computer)
MAP = Manifold Absolute Pressure (the sensor that measures how hard the engine is sucking air through the intake manifold
EEPROM = Electrically Erasable Programmable Read Only Memory (a type of computer chip used inside the PCM)

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1 Answer

Will not stay running like running out of gas i have a 94 jeep cherokee


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Jul 16, 2011 | 1994 Jeep Grand Cherokee

1 Answer

My 94 jeep grand cherokee limited acted as though it was running out of gas then it died however it had plenty. now it starts some of the time and only stay running for a short while.


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1 Answer

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1 Answer

How do u replace the fuel pump on a 1998 jeep grand chrerokee


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3 Answers

Trouble code 52 on Jeep Grand Cherokee Limited 5.2L?.


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