SureTrack Community Fix: Canyon Rats

Real Fixes from the SureTrackĀ® expert information resource are documented issues from actual shop repair orders and community discussions. Read on to see how SureTrack can help you correct issues that are not easily diagnosed using OEM information alone. SureTrack is currently available free with the purchase of a current Snap-onĀ® diagnostic software version.

Rodent damage to a vehicle’s wiring harness can be frustrating because you can never be sure you’ve fixed everything they’ve chewed on. SureTrack community member boysshop had a GMC Canyon in the shop that would not start after replacing the wiring harness. They posed the question to the community, and with the help of fellow community member dmckemie12 and others, they were able to resolve the issue quickly.

The following Community Fix summarizes the interaction between members of the community that led to the solution.

2017 GMC Canyon SLE 2.5L

No start, no communication, repaired open in serial data gateway module.

Vehicle had rodent damage and now won’t start after repairs.

Diagnostic Steps Performed/Parts Replaced
Vehicle came in with wires chewed by rodent. Replaced with OEM wire harness from ECM. Can communicate with BCM, Power steering, EBCM, Telematics, Serial Data, Human Interface, Passenger presence, airbag, HVAC and climate control modules. Cannot communicate with Engine, Transmission, radio, chassis control, frontview camera, IPC and amplifier modules. Battery disconnected. DLC pin 6 & 14 = 133 ohms. Pin 6 & 16 = OL, Pin 14 & 16 = OL, Pin 6 & 4 = OL, Pin 14 & 4 = OL. Battery connected KOEO. Voltage @ pin 6 & 14 = .57V. Voltage @ pin 6 = 3V. Voltage @ pin 14 = 2.5V. Voltage @ pin 6 & grnd = 3.1V. Voltage @ pin 14 & grnd = 2.5V. Given the above. Please advise what I can check. Thank you form your help!

Best Answer from Community Member dmckemie12
The resistance on pins 6 and 14 should be around 60 ohms, you have an open on the ECM side of the high speed data line. Looking at what you can communicate with and what you can’t, it looks like you may have a problem around the Serial Data Gateway Module. I have had a few with pin fitment issues at that module, see if you can wiggle the connector at the module and recheck.

Found open at the serial data gateway module.

Repaired open at the serial data gateway module, vehicle now starts and communicates as it should.

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About the Author

Nick Taylor

Nick Taylor is the SureTrack Community Administrator and a Senior Applications Specialist at Mitchell 1 with over 25 years of experience with electronic repair data systems. Nick previously worked in the automotive dismantling and engine rebuilding industries.