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.

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	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. Using the scan tool, measure ignition voltage. Is voltage within the specified value?	9-18 V	Go to Step 3	Go to DTC P0562 for low voltage or DTC P0563 for high voltage
3	Turn the ignition OFF. Disconnect the 80-way connector at the TCM. Install the J 39700 breakout box, the J-47275 breakout box adapter and the J 47275-1 magnetic overlay. Turn ON the ignition, with the engine OFF. Using the DMM, measure the voltage between connector terminal 51 and ground. Using the scan tool, command SS3 to ON. Is the voltage within the specified value when SS3 is commanded ON?	Less than battery voltage	Go to Testing for Intermittent Conditions and Poor Connections	Go to Step 4
4	Turn the ignition OFF. Disconnect the TCM from the J 39700 . Additional DTCs may set. Turn ON the ignition, with the engine OFF. Using the DMM, measure voltage at terminal 51 and ground. Is the voltage greater than the specified value?	0 V	Go to Step 5	Go to Testing for Intermittent Conditions and Poor Connections
5	Turn the ignition OFF. Disconnect the 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 DMM and the J 35616 GM terminal test kit, measure for voltage at terminal C and ground of the J 44152 . Refer to Inline Harness Connector End Views . Is the voltage greater than the specified value?	0 V	Go to Step 8	Go to Step 6
6	Connect the AT inline 20-way connector. Remove the transmission oil pan. Refer to Oil Pan Replacement . Remove the AT internal wiring harness at the SS3 connector. Using the DMM, measure for voltage at terminal B of SS3 and ground. Is the voltage greater than the specified value?	0 V	Go to Step 9	Go to Step 7
7	Disconnect SS3 from the internal wiring harness. Using the DMM, measure SS3 resistance. Is resistance within the specified value?	22.0 Ω at 20°C (68°F)	Go to Testing for Intermittent Conditions and Poor Connections	Go to Step 10
8	Test the SS3 circuit between the TCM and the AT inline 20-way connector for a short to voltage. Refer to Testing for a Short to Voltage . Did you find and correct the condition?	-	Go to Step 11	-
9	Replace the AT internal wiring harness. Refer to Wiring Harness Replacement . Did you complete the replacement?	-	Go to Step 11	-
10	Replace the SS3. Refer to Control Valve Solenoid Replacement (SS1, SS2, SS3, TCC, and MAIN MOD) or Control Valve Solenoid Replacement (PCS1 and PCS2) . Did you complete the replacement?	-	Go to Step 11	-
11	Perform the following procedure in order to verify the repair: Clear the DTC. Drive the vehicle under normal operating conditions. Select Specific DTC. Enter DTC P0980. 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