I turn vehicle on runs for few minutes and then shuts off and throws code u0100.
Mar 24, 2022 at 5:27 PM
Code U0100
2006 JEEP GRAND CHEROKEE
MOLINASRT8
- MEMBER
- 1 POST
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Hello,
U0100 - Lost Communication with Engine Control Module.
I would suggest checking 12V supply to the PCM, at connector C1, using a test light
Please see image below for the ignition and fused 12V inputs.
Also, check that both ground connections have good connectivity and no excessive resistance.
First check that the 12V inputs light up the test light bright using a good chassis or engine ground.
Then, using either ground pin 9+18 at the PCM, repeat the test. Test light should light up bright. Ensure that you test both pins!
Next start the engine and let it idle. Once it stalls leave ignition on and check each 12V supply again using the test light, see if any supply has dropped out.
How to use a test light.
https://www.2carpros.com/articles/how-to-use-a-test-light-circuit-tester
How to test wiring.
https://www.2carpros.com/articles/how-to-check-wiring
Please let us know how you get along.
Cheers, Boris
U0100 - Lost Communication with Engine Control Module.
I would suggest checking 12V supply to the PCM, at connector C1, using a test light
Please see image below for the ignition and fused 12V inputs.
Also, check that both ground connections have good connectivity and no excessive resistance.
First check that the 12V inputs light up the test light bright using a good chassis or engine ground.
Then, using either ground pin 9+18 at the PCM, repeat the test. Test light should light up bright. Ensure that you test both pins!
Next start the engine and let it idle. Once it stalls leave ignition on and check each 12V supply again using the test light, see if any supply has dropped out.
How to use a test light.
https://www.2carpros.com/articles/how-to-use-a-test-light-circuit-tester
How to test wiring.
https://www.2carpros.com/articles/how-to-check-wiring
Please let us know how you get along.
Cheers, Boris
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Mar 24, 2022 at 8:07 PM
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