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Daniel Wilson
Daniel Wilson,
Category: Medium and Heavy Trucks
Satisfied Customers: 4373
Experience:  Owner at DJ Wilson
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My fan comes on with check engine light and engine brake

Customer Question

My fan comes on with check engine light and engine brake quits working 09 Pete 387 425 ISX.
Submitted: 3 months ago.
Category: Medium and Heavy Trucks
Expert:  Daniel Wilson replied 3 months ago.

Hi Christopher, My name is***** will be glad to help. What are the complete code numbers you are getting?

Customer: replied 3 months ago.
Is there any way to pull codes without a computer
Expert:  Daniel Wilson replied 3 months ago.

Try cruise off key on and hold set/resume until the check engine light begins flashing the 3 digit code. Short pauses between each digit and a longer pause between each code. It will repeat. Let me know

Customer: replied 3 months ago.
Key turned to on truck off cruise switch off and held resume and set both ways and get nothing.
Customer: replied 3 months ago.
It seems like when the coolant temp drops below 185 deg the engine brake stops working after it gets back above that it starts working again
Expert:  Daniel Wilson replied 3 months ago.

Click on this link for the flash code procedure. If it does not work a scan tool would need to be connected.

Flash codes

Expert:  Daniel Wilson replied 3 months ago.

That is odd. Possible unrelated but could be temperature related. Do you have access to a scan tool that reads live data or Cummins Insite to be able to check the ECM parameters and historical faults logged?

Customer: replied 3 months ago.
I don't I just bought the truck 3 weeks ago so don't have the money for that yet I have talked to peterbilt and they haven't heard of it either. I do know it was hooked up at home and it had 360 hits on something to do with the crankshaft but that's all I know. Are the fan and engine brake tied together in any way?
Expert:  Daniel Wilson replied 3 months ago.

Are you losing speedo or tach at all indicating a loss of engine speed signal or vehicle speed signal to the ECM?

Customer: replied 3 months ago.
No
Expert:  Daniel Wilson replied 3 months ago.

The only common link between the fan and engine brake is the ECM but the two circuits are unrelated.

Expert:  Daniel Wilson replied 3 months ago.

Click this link for some troubleshooting help for the engine brake. The rest will need to be accessed with Cummins Insite to monitor switch status, etc.

Troubleshooting

Customer: replied 3 months ago.
Could this be and ecm issue how do I know if software is up to date
Expert:  Daniel Wilson replied 3 months ago.

any Cummins authorized dealer can look this up by your engine serial number. Records of all updates go into a main system for all Cummins authorized service centers to access. Yes it is possible this could be ECM related.