Diagnostic Procedure
WARNING: This page is about a different car, the 2002 GMC Cab & Chassis Sierra 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.
- Perform the transmission fluid checking procedure. See appropriate AUTOMATIC article in TRANSMISSION SERVICING. Was the fluid checking procedure performed? If so, go to next step. If not, see appropriate AUTOMATIC article in TRANSMISSION SERVICING.
- Install a scan tool. Turn ignition on, engine off. Before clearing the DTC, use the scan tool to record the failure records. Using the CLEAR INFO function erases the failure records from the PCM. Record the DTC failure records. Clear the DTC. Does the scan tool display a TFT sensor signal voltage greater than 4.92 volts? If so, go to next step. If not, see DIAGNOSTIC AIDS .
- Does the scan tool display a TFT voltage greater than 5.1 volts? If so, go to step 11 . If not, go to next step.
- Turn ignition off. Disconnect the transmission in-line 20-way connector. Multiple DTCs may set. Install Jumper Harness (J-44152) on the engine side of the transmission in-line 20-way connector. Using a DVOM and the Connector Test Adapter Kit (J-35616-A), measure the voltage between jumper harness terminal "L" and a good ground. Turn ignition on, engine off. Does the voltage measure 4.9-5.0 volts? If so, go to next step. If not, go to step 10 .
- Turn ignition off. Install a fused jumper wire between jumper harness terminals "L" and "M". Turn ignition on, engine off. Does the TFT sensor signal voltage measure less than 0.2 volt? If so, go to next step. If not, go to step 12 .
- Turn ignition off. Install the jumper harness to the transmission side of the transmission in-line 20-way connector. Measure the resistance between jumper harness terminals "L" and "M". Does the resistance measure 16 k/ohms at 50°F (10°C) to 133 ohms at 230°F (110°C)? If so, see DIAGNOSTIC AIDS . If not, see next step.
- Remove the transmission oil pan. See appropriate AUTOMATIC article in TRANSMISSION SERVICING. Test the TFT sensor signal circuit (1227) for an open between the transmission in-line 20-way connector and the TFT sensor. Test the TFT sensor low reference circuit (452) for an open between the transmission in-line 20-way connector and the TFT sensor. Did you find an open condition? If so, go to next step. If not, go to step 14 .
- Replace the transmission internal wiring harness assembly. See TRANSMISSION INTERNAL WIRING HARNESS under REMOVAL & INSTALLATION. Did you complete the replacement? If so, go to step 15 .
- Test the TFT sensor signal circuit (1227) for high resistance or an open between PCM connector C1 terminal C9 and the transmission in-line 20-way connector. Did you find and correct the condition? If so, go to step 15 . If not, go to step 13 .
- Test the TFT sensor signal circuit (1227) for a short to voltage between the PCM connector C1 terminal C9 and the transmission in-line 20-way connector. Did you find and correct the condition? If so, go to step 15 . If not, go to step 13 .
- Test the TFT sensor low reference circuit (452) for high resistance or an open circuit between the PCM connector C2 terminal B12 and the transmission in-line 20-way connector. Did you find and correct the condition? If so, go to step 15 . If not, go to next step.
- Replace the PCM. See POWERTRAIN CONTROL MODULE under REMOVAL & INSTALLATION. Did you complete the replacement? If so, go to step 15 .
- Replace the TFT sensor. See TFT SENSOR under REMOVAL & INSTALLATION. Did you complete the replacement? If so, go to next step.
- Perform the following procedure to verify the repair:
- Select DTC.
- Select CLEAR INFO.
- Operate the vehicle so that the TFT sensor indicates a voltage less than 4.92 volts for 10 seconds.
- Select SPECIFIC DTC.
- Enter DTC P0713.
Has the test run and passed? If so, system is okay. If not, go to step 1 .
NOTE:
High voltage (battery voltage) in the signal circuit may cause an open in the TFT sensor.