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Cat Man
Cat Man, Cat Engine Expert
Category: Medium and Heavy Trucks
Satisfied Customers: 8674
Experience:  I am ASE Master Truck Certified.
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Have a mbn c-15 and getting a high voltage code 110-03

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Have a mbn c-15 and getting a high voltage code 110-03 trying to figure out which pin off the ECM we should check and any other suggestions... also when we tie the wires together it doesn't change to 110-04 code stays at 03
JA: What's the make/model/year of your truck? Engine type?
Customer: 03 Kenworth w900b
JA: Anything else you want the truck mechanic to know before I connect you?
Customer: Think that is all
Thanks for asking your question. I will try and help you out.
Do you have a 4 or 2 wire sensor?
Customer: replied 3 months ago.
2 and there is 10volts there instead of 4.5
Thanks for the information.
One side goes to pin 26 of the ecm. The other goes to any good ground. It could be grounded at pin 5 of ecm. But can go to any ground. Depends on the truck.
Customer: replied 3 months ago.
I will check pin 26 see what voltage is coming out of the ecm
10-4. Please reply back if you need more help or have more questions. I am happy to assist.
Customer: replied 3 months ago.
There is 21k ohms on that pin and 10volts on that wire doesn't appear to be have a short w any other wire
Thanks for the information.
There should only be about 5 volts on pin 26.
All that circuit has is a coolant level sensor that's basically a resister. A current high code is an open circuit. If you ground pin 26, the code should go to a -4 current low. If it does not. You have a faulty ecm.
Customer: replied 3 months ago.
Ya when we tie the wires together it doesn't change stays at a -3
It may take up to 30 seconds to change. I would ground pin 26 right out of the ecm and run to ground.
Customer: replied 3 months ago.
We just double checked pin 26 to verify that we were working w the right wire and it doesn't appear to be the right pin to that sensor
Are you checking the rear most ecm truck connector?
Customer: replied 3 months ago.
Thanks for the information. It should be pin 26.
Customer: replied 3 months ago.
Stays a -3
If shorting pin 26 does not make it a -4. I must suspect a bad ecm.
Customer: replied 3 months ago.
I called and checked its still under warranty so I will try that
That's good news. Please reply back if you need more help or have more questions. I am happy to assist.
Cat Man and 2 other Medium and Heavy Trucks Specialists are ready to help you
Customer: replied 3 months ago.
We finally changed the ecm same problem still have 9.5 volts can't get it to change to a -4
Thanks for the information.
That is very strange. The only things that can cause this code is a bad sensor, harness or ecm.
Customer: replied 3 months ago.
New sensor and new ecm...
There must be something wrong in the harness. That's all that left.
Customer: replied 3 months ago.
We'll check it again
10-4. Let me know how you make out.
Customer: replied 3 months ago.
Found the problem whoever did the thermostats last didn't plug they weather pack plug back in on the bottom of the housing... they tested the ecm and said it was bad too but we r good now
Thanks for the update. I'm glad you got it fixed. Good job.

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