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.

Inspect the wiring for poor electrical connections at the TCM. 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 may 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.

Step	Action	Value	Yes	No
Schematic Reference: Automatic Transmission Controls Schematics
1	Did you perform the Diagnostic System Check - Vehicle?	-	Go to Step 2	Go to Diagnostic System Check - Vehicle
2	Inspect the shift linkage for proper adjustment. Refer to Range Selector Lever Cable Adjustment . Is the shift linkage properly adjusted?	-	Go to Step 3	-
3	Install the scan tool. Turn ON the ignition, with the engine OFF. IMPORTANT: Before clearing the DTC, use the scan tool in order to record the Freeze Frame and Failure Records for reference. The Clear Info function will erase the data. Record the DTC Freeze Frame and Failure Records. Clear the DTC. With the scan tool, monitor IMS A/B/C/P status while moving the shift selector through each range. Refer to Transmission Internal Mode Switch Logic . Does each selected transmission range match the scan tool IMS display?	-	Go to Diagnostic Aids	Go to Step 4
4	Turn the ignition OFF. Install the J 39700 breakout box, the J-47275 breakout box adapter and the J 47275-1 magnetic overlay at the TCM. Disconnect the 16-way bypass connector on the J-47275 . Turn ON the ignition, with the engine OFF. In sequence, connect terminal 58 to terminals 14, 34, 53, and 73 to ground. Using the scan tool, monitor IMS A/B/C/P status. Does each IMS signal indicate OFF when grounded and ON when open?	A = terminal 73 B = terminal 53 C = terminal 14 P = terminal 34	Go to Step 5	Go to Step 10
5	Turn the ignition OFF. Connect the 80-way connector to the TCM. Disconnect the transmission AT inline 20-way connector. Additional DTCs may set. Install the J 44152 jumper harness (20 pins) on the engine side of the AT inline 20-way connector. Turn ON the ignition, with the engine OFF. Using the J 35616 GM terminal test kit, connect a fused jumper wire, in sequence, to terminals T, U, V and W to ground. Refer to Inline Harness Connector End Views . Does each IMS signal indicate OFF when grounded and ON when open?	-	Go to Step 6	Go to Step 7
6	Turn the ignition OFF. Connect the transmission AT inline 20-way connector. Remove the transmission oil pan. Refer to Oil Pan Replacement . Remove the AT internal wiring harness at the IMS connector. Turn ON the ignition, with the engine OFF. Using the J 35616 , connect a fused jumper wire, in sequence, to terminals B, D, C and E to ground. Does each IMS signal indicate OFF when grounded and ON when open?	-	Go to Step 9	Go to Step 8
7	Test the IMS circuit between the TCM and AT inline 20-way connector for an open or short to ground condition. Refer to Circuit Testing . Did you find and correct the condition?	-	Go to Step 11	-
8	Replace the internal wiring harness. Refer to Wiring Harness Replacement . Did you complete the replacement?	-	Go to Step 11	-
9	Replace the internal mode switch. Refer to Transmission Internal Mode Switch Replacement . Did you complete the replacement?	-	Go to Step 11	-
10	IMPORTANT: In most cases, the TCM is not at fault. Investigate thoroughly before replacing the TCM. Replace the TCM. Refer to Control Module References for replacement, setup, and programming.Did you complete the replacement?	-	Go to Step 11	-
11	Perform the following procedures in order to verify the repair: Clear the DTC. With the scan tool, monitor IMS A/B/C/P status while moving the shift selector through each range. Select Specific DTC. Enter DTC P0706. Has the test run and passed?	-	Go to Step 12	Go to Step 2
12	With the scan tool, observe the stored information, capture info and DTC info. Does the scan tool display any DTCs that you have not diagnosed?	-	Go to Diagnostic Trouble Code (DTC) List - Vehicle	System OK