Diagnostic Procedure
WARNING: This page is about a different car, the 2002 GMC Sierra, 2002 GMC Cab & Chassis Sierra, 2002 Chevrolet Silverado, and 2002 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
- Did you perform the diagnostic system check? If so, go to next step. If not, see DIAGNOSTIC SYSTEM CHECK under SELF-DIAGNOSTIC SYSTEM.
- Inspect the engine cooling system for air flow restrictions, blockage or debris. Inspect the transmission cooling system for air flow restrictions, blockage or debris. Check for damaged cooler lines or hoses, or low transmission fluid cooler flow. See appropriate AUTOMATIC article in TRANSMISSION SERVICING. Did you perform the inspection and correct the conditions if necessary? If so, go to next step. If not, see appropriate AUTOMATIC article in TRANSMISSION SERVICING.
- Check the transmission fluid level. See appropriate AUTOMATIC article in TRANSMISSION SERVICING. Is the transmission fluid level correct? If so, go to next step. If not, see appropriate AUTOMATIC article in TRANSMISSION SERVICING.
- Turn ignition off. Install Breakout Box (J-39700) and Breakout Box Adapter (J-43799) at TCM C2 connector. Turn ignition on, engine off. Using DVOM, check the voltage between TCM connector C2 terminals No. 10 and 20. Is the voltage 4.75-5.25 volts? If so, go to next step. If not, go to step 12.
- Install the scan tool. Turn ignition on, engine off. Record the DTC failure records. Clear the DTC. Select TFT on the scan tool. Record the starting temperature and drive the vehicle. Monitor the sump temperature as it increases. Watch for the following: Does transmission fluid temperature change less than 2.7°F (1.5°C) in 100 seconds? Does transmission fluid temperature change more than 2.7°F (1.5°C) in one second? Did either of these conditions occur? If so, go to next step. If not, see DIAGNOSTIC AIDS .
- Disconnect transmission in-line 20-way connector. Measure the resistance of the TFT sensor between transmission in-line 20-way connector terminals "G" and "H". See COMPONENT RESISTANCE under ELECTRONIC COMPONENT SPECIFICATIONS. Is the resistance correct for the sump fluid temperature observed? If so, go to next step. If not, go to step 9.
- Reconnect the transmission in-line 20-way connector. Disconnect the C2 connector at the TCM. Measure the resistance between TCM connector C2 terminals No. 10 and 20. See COMPONENT RESISTANCE under ELECTRONIC COMPONENT SPECIFICATIONS. Is the resistance correct for the transmission fluid temperature observed? If so, see DIAGNOSTIC AIDS . If not, go to next step.
- Repair the vehicle wiring harness. Is the repair complete? If so, go to step 13.
- Remove the oil pan. See appropriate AUTOMATIC article in TRANSMISSION SERVICING. Disconnect the wiring harness from the pressure switch manifold. Measure the resistance between pressure switch manifold terminals "E" and "F". See COMPONENT RESISTANCE under ELECTRONIC COMPONENT SPECIFICATIONS. Is the resistance correct for the transmission fluid temperature observed? If so, go to next step. If not, go to step 11.
- Replace the internal wiring harness. See TRANSMISSION INTERNAL WIRING HARNESS under REMOVAL & INSTALLATION. Is the replacement complete? If so, go to step 13.
- Replace the pressure switch manifold. See PRESSURE SWITCH MANIFOLD under REMOVAL & INSTALLATION. Is the replacement complete? If so, go to step 13.
- Replace the TCM. See TRANSMISSION CONTROL MODULE under REMOVAL & INSTALLATION. Is the replacement complete? If so, go to next step.
- Perform the following procedure to verify the repair:
- Clear the DTC.
- Using the scan tool, monitor the transmission fluid temperature.
- Drive the vehicle under normal operating conditions.
Look for significant changes in transmission fluid temperature. Did the DTC return? If so, go to step 1. If not, system is okay.
NOTE:
DTC P0711 usually indicates an intermittent open or short at the thermistor or wiring.
NOTE:
If breakout box and breakout box adapter are available, use to perform this operation.
CAUTION:
In most cases, the TCM is not at fault. Investigate thoroughly before replacing the TCM.