Diagnostic Aids

Perform this test only when directed by QUICK TEST. This test is intended to diagnose:

• Wiring harness circuits (CCS, SS1, SS2, SS3, EPC, TCC, TFT, and TR).
• Powertrain Control Module (PCM).

Fig 1: E4OD Transmission Circuit & Wiring Connector Terminal ID ("E" & "F" Series)

Fig 2: AODE & 4R70W Transmission Circuit & Wiring Connector Terminal ID ("E" Series)

90)  Drive Cycle Test (4R55E, 4R70W, AODE & E4OD)

Ensure all components are connected. Ensure transmission fluid level is correct. Warm engine to normal operating temperature. Perform KOEO SELF-TEST, and record all continuous memory codes. Clear all codes.

With transmission gear selector in Drive, press Transmission Control Switch (TCS). Transmission Control Indicator Light (TCIL) should come on. Moderately accelerate vehicle to 40 MPH for at least 15 seconds (30 seconds above 4000 feet elevation). Transmission should be in 3rd gear. While holding speed steady, press TCS. TCIL should go off. Accelerate from 40 MPH to 50 MPH. Transmission should shift from 3rd gear to 4th gear. Hold speed steady for 15 seconds. While holding speed steady, lightly apply and release brakes to turn brakelights on. Maintain 50 MPH for about 5 seconds. Stop and park vehicle for a minimum of 20 seconds with transmission gear selector in Drive. Repeat procedure 5 times.

After completing DRIVE CYCLE TEST, perform KOEO SELF-TEST, and record all continuous memory codes. If Code 111 is present, fault cannot be duplicated at this time. If Code 624, 634 or 651 is present, go to next step. If Code 452 is present, go to CIRCUIT TEST DS.

If Code 667 or 668 is present, go to step 93). If any other code(s) is present, go to step 92).

Fig 3: TR Sensor Circuit & Wiring Connector Terminal ID (AODE, 4R70W & 4R55E)

Fig 4: TR Sensor Circuit & Wiring Connector Terminal ID (E4OD)

91)  Code 624, 634 Or 651

Codes 624 and 651 indicate Electronic Pressure Control (EPC) failure. Code 634 indicates Transmission Range (TR) sensor is out of calibration. Possible causes for these faults are:

• Faulty EPC solenoid.
• Faulty TR sensor.
• Circuit open or grounded.
• Damaged PCM connector pins.

Turn ignition off. Disconnect 60-pin PCM connector. Inspect connector for damaged pins, corrosion and loose wires. Repair as necessary. Install EEC-IV Breakout Box (T83L-50-EEC-IV). Connect PCM to breakout box. To test EPC solenoid, connect DVOM to EPC test pin and EPC VPWR test pin at breakout box. To test TR sensor, connect DVOM to TR test pin and test pin No. 46 at breakout box. For EPC solenoid and TR sensor, turn ignition on. Voltage for EPC should be less than 10 volts. Voltage for TR should be less than 5 volts. Shake and bend EPC/TR wiring harness. Lightly tap on components to simulate road shock. Voltage should remain stable. If voltage changes or exceeds specification, fault in circuit is indicated. If fault is indicated, isolate and repair as necessary. Clear continuous memory codes, and repeat QUICK TEST. If no faults are found, problem cannot be located at this time.

92)  Check Circuit Harness & Connectors

Enter CONTINUOUS MONITOR MODE. Shake and bend EEC wiring harness while observing analog VOM or scan tool. Lightly tap on components to simulate road shock. If VOM indicator has erratic movement or scan tool beep, fault is indicated. If fault is indicated, isolate and repair as necessary. Clear continuous memory codes, and repeat QUICK TEST. If no faults are found, problem cannot be located at this time.

93)  Check For Code 659

Code 659 indicates high vehicle speed detected while vehicle was in Park. Possible causes for this fault are:

• Faulty Transmission Range (TR) sensor.
• Faulty Powertrain Control Module (PCM).

If Code 659 is present after performing drive cycle test in step 90), go to step 103). If Code 659 is not present after performing drive cycle test in step 90), go to next step.

94)  Check For Code 675

Code 675 indicates TR circuit voltage is out of range. Possible causes for this fault are:

• Faulty TR sensor.
• Open or short circuit.
• Short to power or ground in SIG RTN circuit.
• Faulty Powertrain Control Module (PCM).

If Code 675 is present after performing drive cycle test in step 90), go to next step. If Code 675 is not present after performing drive cycle test in step 90), go to step 98).

95)  Check For Codes 675 & 667

Code 667 indicates TR circuit voltage is less than self-test minimum voltage. Possible causes for this fault are:

• Faulty TR sensor.
• Open or shorted TR circuit.
• Short to power in TR circuit.
• Faulty Powertrain Control Module (PCM).

If Codes 675 and 667 are present after performing drive cycle test in step 90), go to step 99). If Codes 675 and 667 are not present after performing drive cycle test in step 90), go to next step.

96)  Check For Codes 675 & 668

Code 668 indicates TR circuit voltage is more than self-test maximum voltage. Possible causes for this fault are:

• Faulty TR sensor.
• Open TR circuit.
• Short to power in SIG RTN circuit.
• Faulty Powertrain Control Module (PCM).

If Codes 675 and 668 are present after performing drive cycle test in step 90), go to step 101). If Code 675 and 668 are not present after performing drive cycle test in step 90), go to next step.

97)  Check TR Alignment

Turn ignition off. Apply parking brake. Place transmission gear selector in Neutral position. Place TR Sensor Gauge (T92P-70010-AH) in sensor slot. If gauge does not fit, loosen TR mounting bolts and adjust sensor as necessary. Clear codes and repeat QUICK TEST. If gauge fits, remove gauge and go to next step.

98)  Check For Code 667

Code 667 indicates TR circuit voltage is less than self-test minimum voltage. Possible causes for this fault are:

• Faulty TR sensor.
• Open or short to ground in TR circuit.
• Faulty Powertrain Control Module (PCM).

If Code 667 is present after performing drive cycle test in step 90), go to next step. If Code 667 is not present after performing drive cycle test in step 90), go to step 101).

99)  Check TR Circuit Resistance

Turn ignition off. Disconnect 60-pin PCM connector. Disconnect TR sensor. Inspect connectors for damaged pins, corrosion and loose wires. Repair as necessary. Install EEC-IV Breakout Box (T83L-50-EEC-IV), leaving PCM disconnected. Measure resistance between test pin No. 30 at breakout box and TR terminal at TR sensor connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open circuit. Remove breakout box, reconnect all components, and repeat QUICK TEST.

100)  Check For Short To Ground In TR Circuit

Turn ignition off. Ensure breakout box is installed and TR sensor and PCM are disconnected. Measure resistance between test pin No. 30 at breakout box and chassis ground. If resistance is more than 10,000 ohms, go to step 103). If resistance is 10,000 ohms or less, repair short circuit. Remove breakout box, reconnect all components, and repeat QUICK TEST.

101)  Code 668

Code 668 indicates TR circuit voltage is more than self-test maximum voltage. Possible causes for this fault are:

• Faulty TR sensor.
• Open TR circuit.
• Faulty TR sensor circuit.
• Faulty Powertrain Control Module (PCM).

Turn ignition off. Disconnect 60-pin PCM connector. Disconnect TR sensor. Inspect connectors for damaged pins, corrosion and loose wires. Repair as necessary. Install EEC-IV Breakout Box (T83L-50-EEC-IV), leaving PCM disconnected. Measure resistance between test pins No. 46 at breakout box and SIG RTN terminal at TR sensor connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open circuit. Remove breakout box, reconnect all components, and repeat QUICK TEST.

102)  Check For Short To Power

Ensure PCM and TR sensor are disconnected. Measure resistance between test pin No. 30 and test pins No. 37, 40, 46, 57 and 60 at breakout box. If all readings are more than 10,000 ohms, go to next step. If any reading is 10,000 ohms or less, repair short circuit. Remove breakout box, reconnect all components, and repeat QUICK TEST.

103)  Check TR Sensor Resistance

Turn ignition off. Connect TR sensor. Leave PCM disconnected. Unlock steering column. Measure resistance between test pins No. 30 and 46 at breakout box while cycling gear selector. If resistance is within specification, replace PCM and repeat QUICK TEST. See TR SENSOR RESISTANCE table. If resistance is not within specification, replace TR sensor and repeat QUICK TEST.