After On-Board Diagnostics

NOTE: The vehicle wiring harness, powertrain control module and non-transmission sensors may affect transmission operations. Service these concerns first.

NOTE: After electrical diagnosis has been performed and a concern still exists, refer to the Diagnosis by Symptom Index.

Begin with non-transmission related DTCs, then service any transmission related DTCs. Refer to the On-Board Diagnostic Trouble Code Description Chart for information on condition and symptoms. This chart will be helpful in referring to the proper procedures and to aid in diagnosing internal transmission concerns and external non-transmission inputs. The pinpoint tests are used in diagnosing electrical concerns of the 4R70W transmission. Make sure that the vehicle wiring harness and the powertrain control module are diagnosed as well.