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Old 04-03-2019
JeanLuke  JeanLuke is offline
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Default CAN Bus errors

Any hints? I'm thinking the shifter circuit board.

Edit:
If I just clear the codes, they come straight back. If I shift to 4L and back to 4H they clear successfully. I see them once a week or so. The shifting clearing them is what makes me suspect the shifter PCB, but I guess it also could be a dodgy wire/connection.


Last edited by JeanLuke; 04-03-2019 at 08:04 AM.
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Old 05-03-2019
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Limited ideas, it could be a dirty connector somewhere creating a problem, it may also be the shifter circuit board too.

Could be a PITA to diagnose. I'd send the jeepswj.com people an email and ask what they think.

Jason
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Old 05-03-2019
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Yeah, I was thinking of contacting Kaido.

Since posting, I've looked through the manual again. The ECU, ABS and TCM are directly connected to each other on the CAN network. There are terminating resistors at the TCM and the ABS. I have removed the plug on the ABS and cleaned the terminals. I was playing in that area a few weeks ago, working on the EGR solenoid.

Next step will be pulling the TCM apart and putting it under my magnifying lamp for a crack inspection.

Seeing simultaneous errors from the TCM losing comms with the ECU and the ABS smells like a network wiring issue. This is certainly going to be a challenge to find!
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Old 06-03-2019
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Errors returned today. I had an hour of daylight after I got home from work today, so I pulled out the TCM for a check.

See pictures attached. The CAN works on the front terminals of the C2 connector. They are on their own plug that can be separated from the C2. Should there be that white powdery finish on the CAN terminals?
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Old 06-03-2019
FRANKIDOWNUNDER  FRANKIDOWNUNDER is offline
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In a word, No. In my experience dealing with these types of systems the contacts need to be clean and making a firm connection. Clean both the plugs and sockets with a good quality electrical contact cleaner, preferably one which contains a contact lubricant then assemble, cancel all fault codes and see what happens then. you may still have other bad connectors as well. f you do clean them in a similar fashion. CAN bus voltages are very low, some around 2-3 volts so clean contacts are essential.
Hope this is helpful to you.

Denis.
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Old 06-03-2019
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Thanks. I was being tongue in cheek with the question. I have done exactly as you said with Jaycar contact cleaner/lubricant.

Some 18 months ago I resoldered and lacquered the TCM board. Knowing this, I also gave the terminals a light dusting with WD40 today before putting it all back together. I was careful to hold it terminals down to avoid WD40 going into the PCB.

Edit: The errors were the TCM not communicating with the other modules and the ECU not communicating with the TCM. This is a strong hint that the bad connection is at the TCM.

If it was at the ABS or ECU the TCM would not be complaining about both missing - it would have only been one of the two. If it was a network short, the ECU would be complaining about not seeing the ABS - but it hasn't.

Is my logic sound?

Last edited by JeanLuke; 06-03-2019 at 08:14 PM.
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Old 01-04-2019
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Closing the loop here - almost a month gone without errors. I'm calling it "fixed"

Knowing my Jeep, I pro'lly just jinxed it!
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