C15 Acert BXS shuts off-throws no codes HELP!!!!

To bring on the idiot lights in the dash, you are losing power on the keyed switched circuit. The problem is in the dash, not the ECM. The speedometer gauge erratic response is also a sign of the same problem with the engine surging when the ECM is getting an erratic 12 volt keyed signal. The ECM reads the speed sensor signal and forwards it to the gauge in the dash. So if the engine is surging erratically while the speedometer is, then the ECM is losing keyed power. This will not leave any fault codes, because the ECM can't tell the difference between someone turning off the ignition switch versus the 12 volt positive signal being interrupted by a broken or corroded wiring harness in the truck somewhere. If you want to run a test to see if it is the truck you need to run a 12 volt positive signal to pin 70. The problem has to be coming from the ignition key source that supplies the 12 volts positive or from the ignition switch or ignition switch wiring harness used to power up the truck after the switch.

 

Mr. Haney You just explained the problem a buddy of mine has been having with his older truck. It makes sense when a person can see it in print. Many thanks.

 

Hey Did you end up resolving the issues with your truck shutting off having the same issue with my truck. I replaced the ECM with a loaner that peterbilt dealer had and the issue continues to happen!!

 

I am curious also

 

So I googled this and read the entire feed only to find out the outcome was never posted!!! Anyone know what's next?

 

Had the same problem over a year ago when I found this thread. I followed the wire from pin70 and found a short. After fixing the wire haven't had a problem since.

 

Not sure if this will help anyone but we have had several 04/05 bxs and mxs cat engines that would momentarily shut off then right back to power without showing a code. I have seen 2 separate causes, first being rubbed wire coming out of battery box. Next being bad wire at crank sensor (usually couple inches before connection at crank driver side around power steering pump.) Yes this has happened with no codes. Leave truck idle and start moving wires at these areas to see if shuts down.

 

We hava kenworth C15 went down the road en just like that it shut off no codes coming on nothing everything worked perfect till then it’ll only turn over but won’t fire any help on that ?