6HP26 Automatic Transmission
Transmission Drive Cycle TestMaterial:
NOTE: Always drive the vehicle in a safe manner according to driving conditions and obey all traffic laws.
NOTE: The Transmission Drive Cycle Test must be followed exactly. Malfunctions must occur 4 times consecutively for shift error DTC code to be set, and 5 times consecutively for continuous TCC code to set.
NOTE: When carrying out the Transmission Drive Cycle Test refer to the Solenoid Application Chart for correct solenoid operation.
After carrying out the Quick Test, use the Transmission Drive Cycle Test for checking continuous codes.
1. Record and then erase Quick Test codes.
2. Warm engine to normal operating temperature.
3. Make sure transmission fluid level is correct.
4. With transmission in D6, moderately accelerate from stop to 80 km/h (50 mph). This allows the transmission to shift into 6th gear. Hold speed and throttle open steady for a minimum of 15 seconds.
5. With transmission in 6th gear and maintaining steady speed and throttle opening, lightly apply and release brake to operate stop lamps. Then, hold speed and throttle steady for a minimum of 5 seconds.
6. Brake to a stop and remain stopped for a minimum of 20 seconds.
7. Repeat Steps 4 through 6 at least 5 times.
8. Carry out Quick Test and record continuous DTC's.
^ If the DTC's are still present, refer to the Diagnostic Trouble Code Chart. Repair all non-transmission DTC's first as they can directly affect the operation of the transmission. Repeat the Quick Test and the Road Test to verify the correction. Erase the DTC's, carry out the Drive Cycle Test and repeat the Quick Test after completing the repair on the DTC.
^ If the continuous test passes and a concern is still present refer to Diagnosis By Symptom Diagnosis By Symptom.
After On-Board Diagnostic
NOTE: The vehicle wiring harness, PCM and non-transmission sensors may affect transmission operations. Repair these concerns first.
After the on-board diagnostic procedures are completed, repair all DTC's.
Begin with non-transmission related DTC's, then repair any transmission related DTC's. Use the diagnostic trouble code chart for information on condition and symptoms. This chart will be helpful in referring to the correct manual(s) and aids in diagnosing internal transmission concerns and external non-transmission inputs. The pinpoint tests are used in diagnosing transmission electrical concerns. Make sure that the vehicle wiring harness and the PCM are diagnosed as well. The Computers will aid in diagnosing non transmission electronic components.