A few weeks ago I had an issue with starting. The engine would hesitate a moment before coming up to normal idle RPM. Around the same time, it started misbehaving in other ways. Engine had reduced power. Accelerated very slowly, especially up hills. Felt like I was taking off in 2nd gear. Transmission indicator light went out, cruise control disabled, and some other things. DIC is flashing "Service airbags / traction control / stabilitrak". When I release the brake, I hear a click somewhere inside the instrument panel. System voltage with the engine running is normal.

I assumed it was a bad battery, but I didn't have time to deal with it. In the meantime, temperatures rose, and now the van starts perfectly every morning. But the reduced power + DIC messages persist. Finally today, I went to a battery dealer. He tested my battery and it was in great shape (ACDelco Professional Gold, ~3 yrs old). So now I'm stumped.

I read that the DIC messages were a common problem for GM pickups, caused by a faulty ground on the frame wiring harness, directly below the driver. When I got home I sanded the ground mating surfaces clean and reconnected, but no change. Has anyone else experienced this issue?

2013 Savana 5.3L

 

I had the reduced power and service airbag message last spring. I reset the codes and it started and ran fine. The next day it did the same thing. I replaced relays 15 and 39 and the problem hasn't shown back up. However, this is an RV and it is driven only about 5k miles per year.

Gary

 

what did the relays do?

 

One was labeled "Crank" and the other "Run/Start". No idea why they helped! To test, I replaced the run'start one with the AC relay. It started without any messages or codes. Having said all this, Friday I'm replacing the starter due to a no crank issue that seems to pop up when the unit idles for an extended time. I can hear the solenoid "click" so, I'm hopeful it is just the starter.
Gary

 

Any code stored ?

Any similarities ? : https://chevroletforum.com/forum/tah...l-45015/page9/

 

none that my Scanguage can read

 

Hi, this happened to me in 2016, might be similar to yours.

https://chevroletforum.com/forum/exp...17/#post323139

 

Thank you for sharing. Do you remember where exactly the fault lay?

I took the van to a general mechanic today, where they ran a diagnostic scan. The transmission control module isn't responding. There's a problem with the module, or the wiring.
They sent me to a transmission specialist. The transmission guy said it was an electrical problem, and referred me to a auto electrical specialist. I have an appointment there next week.

If anybody has pin-outs or diagrams for the tranny & TCM on a 2013 1500 that would be most helpful. This weekend I'll get out the multi meter and start checking for power, ground, and continuity on the other circuits. I'm starting to sweat a bit because I'm moving to the next province (1,100km through the mountains, towing a trailer) in about a week.

 

U0101 Lost communications with Transmission Control Module (TCM)

 

Unless you think you're able to trace the fault to the TCM, might also do like we did with my electrical short. I don't know if you have removed the doghouse, but it has to be removed, along with the passenger seat. Then plug in your scanner, key on the engine off, start giggling the bundles of wires in the engine harness, looking for rubbing wires on brackets on top of the engine. The scanner will react when a break in a wire touches again, then narrow it down to a certain bundle and find the break. Like in the third picture, good luck.