Diagnostic Aids

WARNING: This page is about a different car, the 2008 GMC Sierra, 2008 GMC Cab & Chassis Sierra, 2008 Chevrolet Silverado, and 2008 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

IMPORTANT: Due to the TCM logic used to detect and set DTC P0708, this code can remain active even after an IMS switch replacement is complete and the ignition has been cycled. Therefore, always clear all active DTCs from the TCM after servicing the IMS switch.

Inspect the wiring for poor electrical connections at the TCM and powertrain control module (PCM). Inspect for the following conditions:
- A bent terminal
- A backed-out terminal
- A damaged terminal
- Poor terminal tension
- A chafed wire
- A broken wire inside the insulation
When diagnosing for an intermittent short or open, massage the wiring harness while watching the test equipment for a change.
You may have to drive the vehicle in order to experience a condition.
Due to this failure and associated response, DTC P0722 can also set.
When monitoring "TR SW" while moving the selector through ranges, A/B/C/P states may indicate transitional states. Transitional states are the area between ranges.
TR SW A/B/C/P may indicate invalid states when selecting ranges. Invalid states confirm a concern is present.