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Cat Man
Cat Man, Cat Engine Expert
Category: Medium and Heavy Trucks
Satisfied Customers: 8414
Experience:  I am ASE Master Truck Certified.
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Cat c15 not acert will not start unless #6 injector unplugged.

Customer Question

cat c15 not acert will not start unless #6 injector unplugged. wiring ohmed good. did replace injector and harness due to burned looking wiring. am sure after all the test except no test ecm it is the #6 ecm injector driver. but this will be second ecm in a month after a overhaul was done with new injectors and exact same fault. worried what could knock out the driver
Submitted: 7 months ago.
Category: Medium and Heavy Trucks
Expert:  Cat Man replied 7 months ago.
Thanks for asking your question. I will try and help you out.
Typically nothing should be able to take out an injector driver. However I have seen low battery voltage to the ECM cause a no start.
The DC voltage to the ECM must not drop below 7.5 volts while cranking. If it does. The ECM can't function. I would check this first.
If the voltage is good. I must suspect the ECM. The good news is if the ECM was replaced a month ago. It should have warranty.
Please reply back if you need more help or have more questions. I am happy to assist.
Customer: replied 7 months ago.
Voltage is fine. Engine cranks fine but will not start, it will start if number 6 injector is unplugged
Expert:  Cat Man replied 7 months ago.
Thanks for the information.
Is there any codes being set? Like injector codes?
Expert:  Cat Man replied 7 months ago.
Hey. I just wanted to see how things were going. Please let me know if you need more help. I am happy to assist. If my information was helpful, please leave a good or higher rating so that I receive credit. Thanks.
Customer: replied 7 months ago.
Had number 6 fault code and if unplugged would run. Did find way from cat to ohm inj for shorted solenoid. Old inj was good. It was the ecm injector driver that failed. He was able to warranty the ecm. Nothing caused ecm failure. Just did. Would not run with number 6 injector plugged in due to number 5 and 6 share the same common , and a cat wont run on 4 cylinders due to the short circuit driver in ecm
Expert:  Cat Man replied 7 months ago.
Thanks for the update. I thought it would end up being the ECM. I'm glad you got it fixed. Please do not forget to leave a positive rating so that I receive credit. Thanks.
Expert:  Cat Man replied 6 months ago.
Hey. I just wanted to see how things were going. Please let me know if you need more help. I am happy to assist. If my information was helpful, please leave a good or higher rating so that I receive credit. Thanks.