On-Board Diagnostics With NGS

PERFORM ON-BOARD DIAGNOSTICS
After a road test, with the vehicle warm and before disturbing any connectors, perform the Quick Test using New Generation Star (NGS) Tester.

DIAGNOSTICS
Diagnosing an electronically controlled automatic transmission is simplified by using the following procedures. One of the most important things to remember is that there is a definite procedure to follow. Do not take short cuts or assume that critical checks or adjustments have already been made. Follow the procedures as written to avoid missing critical components or steps. By following the diagnostic sequence, the technician will be able to diagnose and repair the concern the first time.

ON-BOARD DIAGNOSTICS WITH NGS
NOTE:New Generation Star (NGS) Tester or equivalent must be used on EEC-V equipped vehicles in order to retrieve four-digit DTCs properly.

The Quick Tests can be used to diagnose the Powertrain control module (PCM), sensors and actuators of the E4OD transmission.

OTHER NGS FEATURES
For further information on other diagnostic testing features using the NGS or generic scan tool, refer to Powertrain Management. Other diagnostic methods include the following:
- Parameter Identification (PID) Access Mode, used to monitor sensors and actuators.
- Freeze Frame Data Access Mode, used to view emission related data values from specific PID's.
- Oxygen Sensor Monitor Mode, used to monitor the Heated Oxygen (HO2S).

AFTER ON-BOARD DIAGNOSTICS
NOTE: The vehicle wiring harness, powertrain control module (PCM) and non-transmission sensors can affect transmission operations. Repair these concerns first.

After the On-Board Diagnostics procedures are completed, repair all DTCs.

Begin with non-transmission-related DTCs, then repair any transmission-related DTCs. Refer to the Diagnostic Trouble Code Chart for information on condition and symptoms. This chart will be helpful in referring to the proper manual(s) and to aid in diagnosing internal transmission concerns and external non-transmission inputs. The pinpoint tests are used in diagnosing electrical concerns of the E4OD transmission. Make sure the vehicle wiring harness and the powertrain control module are diagnosed as well.

BEFORE PINPOINT TESTS
NOTE: Prior to performing pinpoint tests, check the powertrain control module wiring harness for proper connections, bent or broken pins, corrosion, loose wires, proper routing, proper seals and their condition. Check the powertrain control module (PCM), sensors and actuators for damage.

If DTCs appear while performing the diagnostics, refer to the Diagnostic Trouble Code Chart for the appropriate procedure. Prior to entering pinpoint tests, refer to any TSBs for E4OD transmission concerns.

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