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Daniel Wilson
Daniel Wilson,
Category: Medium and Heavy Trucks
Satisfied Customers: 5424
Experience:  Owner at DJ Wilson
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I am working a c15 caterpillar in a peterbilt and when

Customer Question

I am working a c15 caterpillar in a peterbilt and when driver should get a check engine light nothing shows up on the dash and we have come to the conclusion the cluster that the lights come through on the dash must be faulty can someone tellme what pin on the ecm is for the check engine light? (yellow)
Submitted: 1 year ago.
Category: Medium and Heavy Trucks
Expert:  Daniel Wilson replied 1 year ago.

Hi my name is ***** ***** will be glad to help. What is the year make and model of the truck this is in and also the first three digits of the engine serial number (Prefix) ?

Customer: replied 1 year ago.
2006 386 Pete and it's a nxs engine
Expert:  Daniel Wilson replied 1 year ago.

Thanks for the update. Click on this link for the Information you requested.

Diagram

Expert:  Daniel Wilson replied 1 year ago.

What symptoms are you having? If the engine wont start and there is no check engine light then check the inline fuse between the batteries and ECM as the ECM has likely lost power. If everything is okay and operation is normal but the check engine light does not come on it could be the bulb itself in the cluster. Let me know

Customer: replied 1 year ago.
The engine runs fine but when the driver is having a issue say overheat or any other codes that pops up the ecm registers it but the drivers is not aware of it so i need to know what pin is sending out signal to the dash for the check engine light as if i unplug a sesnor and my laptop (et) shows a active code the dash does not register it
Expert:  Daniel Wilson replied 1 year ago.

Pin 28 wire 994 YL

Customer: replied 1 year ago.
ok great i will check it is it a ground or a power coming out ? i guess i will find out lol thanks
Expert:  Daniel Wilson replied 1 year ago.

I took a snapshot of that area of the schematic. One lead is from battery and the other from the 994 YL wire

Expert:  Daniel Wilson replied 1 year ago.

Let me know if you need more help and please remember to take a few moments to rate my service as that is how the site credits the experts for their time helping on the site. Pleasure to help.

Customer: replied 1 year ago.
It shows a constant power with no active codes ?
Customer: replied 1 year ago.
I need this info please
Customer: replied 1 year ago.
Customer: replied 1 year ago.
Truck is leaving tonight
Expert:  Daniel Wilson replied 1 year ago.

Hi, I had to go out on a road call. I help on here in between jobs and nights as I am available. The broken dotted lines are ground. The solid line is power and the other gets grounded through the ECM when the ECM commands the light on. Test for ground at that pin 28 through the ECM when you unplug some sensors to throw a code.

Customer: replied 1 year ago.
I first had sensor unplugged verified active code then check pin 28 constant power then I hooked sensor back up then cleared codes still constant power thanks
Expert:  Daniel Wilson replied 1 year ago.

Constant power at pin 28? Try Grounding the 994 YL wire on the ECM side of the light. See if the light comes on. If it does not then check for a faulty bulb. The other side of the circuit shows bat power.

Customer: replied 1 year ago.
It's mounted in a dash module board no bulbs so we either replace a 1200 module or wire in our own bulb system owner wants to go the cheaper route is why I have even reprogrammed dash cluster with Paccar laptop/software
Expert:  Daniel Wilson replied 1 year ago.

Thanks for the update. There is a company that rebuilds those clusters for a fraction of that cost.

http://www.instrumentclusters.com/

Expert:  Daniel Wilson replied 1 year ago.

Hi, Did you get this resolved? If so please take a moment to rate my service to close this out. Pleasure to help.