Chevy Colorado Diesel Forum banner
1 - 1 of 1 Posts

1 Posts
Discussion Starter · #1 ·
Have a 2016 Canyon with 77k. Ever since about 20k I have been getting this code on and off. Hasn't really affected drivability, other than when the Check Engine Light is on the engine brake doesn't work when towing.

The code is "ECM/PCM Power Relay Control Circuit Low" . I've read several posts about how the charging system on these trucks keep the battery at a lower voltage than most other vehicles. In the mornings when I crank it, the voltage on the dash readout is usually 12.0-12.2. I'm wondering if the actual voltage drops when cranking to below the threshold to trigger the code.

I haven't load tested the battery yet. Bought the truck in Nov. 2016, so the battery is 3 years old. But it has been throwing this code since 2017. My fault for not taking it in while it was still under warranty.

I've swapped around relays in the fuse box, but I'm not sure if the actual ECM/PCM relay is there or somewhere else. Internet searches have failed to tell me the exact relay, and I haven't seen any posts with others having the same issue.
1 - 1 of 1 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.