Electronic Transmission - Continuous Memory Diagnostic Trouble Codes (DTC)

1994 PCED OBDI-A

SECTION 6A: EEC-IV Pinpoint Test
Procedures

TG: Electronic Transmission - Continuous Memory Diagnostic Trouble Codes (DTC)

TG: Introduction

TG90 PERFORM DRIVE CYCLE TEST

Run Key On Engine Off (KOEO) Self-Test and record all Continuous Memory DTCs displayed.
Clear Continuous Memory (refer to Quick Test Appendix, Section 5A).

Note: Obey all traffic laws.

AX4S Drive Cycle (except 3.2L SHO):

Gear position in OVERDRIVE range, moderately accelerate from stop to 50 MPH. This allows transmission to shift into fourth gear. Hold speed and throttle steady for a minimum of 15 seconds.
With transmission in fourth gear and holding speed and throttle opening steady, lightly apply and release brake. Then hold speed and throttle steady for at least five seconds.
Brake to a stop and remain stopped for a minimum of 20 seconds. Repeat drive cycle at least five times.

4R70W, AODE, CD4E, E4OD and AX4S-3.2L SHO Drive Cycle:

Gear position in DRIVE range, press the Transmission Control Switch (TCS) (the Transmission Control Indicator (TCIL) should light) and moderately accelerate from stop to 40 mph. This will allow the transmission to shift into third gear. Hold speed and throttle opening steady for a minimum of 15 seconds (30 seconds for altitudes above 4000 feet).
Press TCS (the TCIL should turn off) and accelerate from 40 mph to 50 mph. This will allow the transmission to shift into fourth gear. Hold speed and throttle steady for a minimum of 15 seconds.
With transmission in fourth gear and maintaining steady speed and throttle opening, lightly apply and release brake (to operate stop lamps). Then hold speed and throttle steady for at least an additional five seconds.
Brake to a stop and remain stopped for a minimum of 20 seconds with transmission in drive. Repeat drive cycle at least five times.

Rerun KOEO Self-Test and record all Continuous Memory DTCs.

Are pass codes present in Continuous Memory (any code 10-11/111)?

Yes	No
Unable to duplicate fault at this time. For further diagnosis using EEC-IV Monitor Box or Scan Tool, REFER to Section 7A, EEC-IV Monitor Box: Intermittent Fault Diagnosis. If further diagnosis is not performed, then CLEAR Continuous Memory (REFER to Quick Test Appendix, Section 5A) and REFER to appropriate Transmission Group in the Service Manual for possible internal transmission damage.	For DTCs 99/624, 651 or 67/634: GO to TG91 For DTCs 29/452: GO to Pinpoint Test Step DS1 (E/F Series Bronco) For all other vehicles: GO to DP1. For DTCs 659, 667, 668 and 675: GO to TG93. For any other DTC: GO to TG92.

Yes

Unable to duplicate fault at this time. For further diagnosis using EEC-IV Monitor Box or Scan Tool, REFER to Section 7A, EEC-IV Monitor Box: Intermittent Fault Diagnosis. If further diagnosis is not performed, then CLEAR Continuous Memory (REFER to Quick Test Appendix, Section 5A) and REFER to appropriate Transmission Group in the Service Manual for possible internal transmission damage.

For DTCs 99/624, 651 or 67/634:
GO to TG91

For DTCs 29/452:
GO to Pinpoint Test Step DS1 (E/F Series Bronco) For all other vehicles:
GO to DP1.

For DTCs 659, 667, 668 and 675:
GO to TG93.

For any other DTC:
GO to TG92.

TG91 CHECK CIRCUIT FOR INTERMITTENT FAULT IN HARNESS AND CONNECTORS.

DTCs 99/624 and 651 indicate an Electronic Pressure Control (EPC) circuit failure.

DTCs 67/634 indicate the Manual Lever Position (MLP) sensor voltage is higher or lower than expected.

Possible causes

Damaged harness connector.
Damaged EPC solenoid.
Damaged MLP sensor.
Intermittent harness continuity.
Damaged PCM connector pins.

Key off.
Disconnect Powertrain Control Module (PCM). Inspect for damaged or pushed out pins, corrosion, loose wires, etc. Service as necessary.
Install breakout box, connect PCM.
Connect DVOM to test pins as indicated:

For EPC solenoid:
Connect one test lead to EPC signal pin and the other to EPC VPWR pin. Refer to cover page schematics per application for correct EPC test pin.
For MLP sensor:
Connect one test lead to MLP signal pin and the other test lead to Test Pin 46. Refer to cover page schematics per application for correct MLP test pin.

Key on, engine off.
Observe DVOM display for indication of a fault while performing the following:

Note: In either case, the voltage should remain steady (less than 10.0 volts for the EPC and less than 5.0 volts for the MLP with vehicle in PARK). A changing voltage or one greater than expected is an indication of a fault.

Shake, wiggle and bend the component harness.
Lightly tap on the component connector to simulate a road shock.

Is a fault indicated?

Yes	No
ISOLATE fault and SERVICE as necessary. CLEAR Continuous Memory (REFER to Quick Test Appendix, Section 5A). RERUN Quick Test. If the concern still exists, REFER to appropriate Transmission Group in the Service Manual for possible internal transmission damage.	GO to the appropriate Transmission Service Manual Group. CLEAR Continuous Memory (REFER to Quick Test Appendix, Section 5A).

TG92 ENTER KEY ON ENGINE OFF CONTINUOUS MONITOR MODE: CHECK HARNESS CIRCUITS

DTCs 49/617 indicate an improper 1-2 shift.

DTCs 59/618 indicate an improper 2-3 shift.

DTCs 69/619 indicate an improper 3-4 shift.

DTCs 62/628 indicate excessive converter clutch slip detected.

DTCs 56/637 indicate transmission fluid temperature (TFT) sensor circuit above maximum voltage.

DTCs 66/638 indicate transmission fluid temperature (TFT) sensor circuit below minimum voltage.

DTC 645 indicates an incorrect gear ratio after first gear was commanded.

DTC 646 indicates an incorrect gear ratio after second gear was commanded.

DTC 647 indicates an incorrect gear ratio after third gear was commanded.

DTC 648 indicates an incorrect gear ratio after fourth gear was commanded.

DTC 656 indicates continuous slip error was detected.

Possible causes:

Intermittent harness continuity.
Damaged Manual Lever Position (MLP) Sensor.
Damaged shift solenoid.
Worn friction elements.

Enter Key On Engine Off Continuous Monitor Diagnostic Test Mode (DTM). Refer to Quick Test Appendix, Section 5A.
Observe VOM or STAR Tester LED for an indication of a fault while performing the following:

Wiggle, shake or bend a small section of the Powertrain Control Module (PCM) vehicle harness while working toward the dash panel, PCM and transmission connectors.

Is a fault indicated?

Yes	No
DISCONNECT and INSPECT connector and harness wires. SERVICE as necessary. CLEAR Continuous Memory (REFER to Quick Test Appendix, Section 5A). RERUN Quick Test. If the concern remains, REFER to appropriate Transmission Group in Service Manual for possible internal transmission damage.	REFER to appropriate Transmission Group in the Service Manual.

TG93 CHECK FOR DTC 659

DTC 659 indicates high vehicle speed detected while the vehicle was in PARK.

Possible causes:

Damaged Manual Lever Position (MLP) Sensor.
Damaged PCM.

Did DTC 659 repeat during the drive cycle test?

Yes	No
GO to TG103.	GO to TG94.

TG94 CHECK FOR DTC 675

DTC 675 indicates the MLP circuit voltage was out of the expected range.

Possible causes:

Damaged MLP sensor.
Open in MLP harness SIG circuit.
Open in MLP harness SIG RTN circuit.
Short to ground in MLP harness SIG circuit.
Short to power in MLP harness SIG circuit.
Damaged PCM.

Did DTC 675 repeat during the drive cycle test?

Yes	No
GO to TG95.	GO to TG98.

TG95 CHECK FOR DTC 675 WITH DTC 667

DTC 667 indicates the MLP circuit voltage was below the allowed minimum voltage.

Possible causes:

Damaged MLP sensor.
Short to ground in MLP harness SIG circuit.
Open in MLP harness SIG circuit.
Damaged PCM.

Did DTC 675 repeat with DTC 667 during the drive cycle test?

Yes	No
GO to TG99.	GO to TG96.

TG96 CHECK FOR DTC 675 GENERATED WITH DTC 668

DTC 668 indicates the MLP circuit voltage was above the allowed maximum voltage.

Possible causes:

Open in MLP harness SIG RTN circuit.
Damaged MLP sensor.
Damaged PCM.
Short to power in MLP harness SIG circuit.

Did DTC 675 repeat with DTC 668 during the drive cycle test?

Yes	No
GO to TG101.	GO to TG97.

TG97 CHECK MLP ALIGNMENT

Key off.
Apply parking brake.
Place transmission in NEUTRAL.
Verify the MLP tool (Rotunda T92P-7010-AH or equivalent) fits in the appropriate slot.

Does the tool fit properly?

Yes	No
REMOVE tool. GO to TG103.	PLACE the transmission in NEUTRAL, loosen the two MLP sensor mounting bolts. MOVE the sensor about to allow insertion of the MLP sensor tool in the appropriate slots. TIGHTEN the two mounting bolts to specification. REMOVE the tool. VERIFY shift linkage adjustment (REFER to Transmission Group in Service Manual for procedure). CLEAR Continuous Memory (REFER to Quick Test Appendix, Section 5A). RERUN Quick Test.

Yes

REMOVE tool. GO to TG103.

PLACE the transmission in NEUTRAL, loosen the two MLP sensor mounting bolts. MOVE the sensor about to allow insertion of the MLP sensor tool in the appropriate slots. TIGHTEN the two mounting bolts to specification. REMOVE the tool. VERIFY shift linkage adjustment (REFER to Transmission Group in Service Manual for procedure). CLEAR Continuous Memory (REFER to Quick Test Appendix, Section 5A). RERUN Quick Test.

TG98 CHECK FOR DTC 667

DTC 667 indicates the MLP circuit voltage was below the allowed minimum voltage.

Possible causes:

Damaged MLP sensor.
Short to ground in MLP harness SIG circuit.
Open in MLP harness SIG circuit.
Damaged PCM.

Did DTC 667 repeat during the drive cycle test?

Yes	No
GO to TG99.	GO to TG101.

TG99 CHECK CONTINUITY OF THE TR HARNESS SIG CIRCUIT

Key off.
Disconnect Powertrain Control Module (PCM). Inspect for damaged or pushed out pins, corrosion or loose wires, etc. Service as necessary.
Disconnect MLP sensor.
Using a mirror, inspect both ends of transmission harness connector at MLP sensor for damaged or pushed out pins, corrosion, loose wires, etc. Service as necessary.
Install breakout box, leave PCM disconnected.
Measure resistance between Test Pin 30 at the breakout box and MLP SIG circuit at the MLP sensor vehicle harness connector.

Is resistance less than 5.0 ohms?

Yes	No
GO to TG100.	SERVICE open circuit. REMOVE breakout box. RECONNECT all components. RERUN Quick Test.

TG100 CHECK FOR SHORT TO GROUND IN MLP HARNESS SIG CIRCUIT

Key off.
MLP sensor disconnected.
Breakout box installed, PCM disconnected.
Measure resistance between Test Pins 30 at the breakout box and chassis ground.

Is resistance greater than 10,000 ohms?

Yes	No
GO to TG103.	SERVICE short circuit. REMOVE breakout box. RECONNECT all components. RERUN Quick Test.

TG101 DTC 668 WAS GENERATED DURING THE DRIVE CYCLE TEST: CHECK FOR CONTINUITY OF THE MLP HARNESS SIG RTN CIRCUIT

DTC 668 indicates the MLP circuit voltage was above the allowed maximum voltage.

Possible causes:

Open in MLP harness SIG RTN circuit.
Damaged MLP sensor.
Damaged PCM.
Short to power in MLP harness SIG circuit.

Key off.
Disconnect Powertrain Control Module (PCM). Inspect for damaged or pushed out pins, corrosion or loose wires, etc. Service as necessary.
Disconnect MLP sensor.
Using a mirror, inspect both ends of transmission harness connector at MLP sensor for damaged or pushed out pins, corrosion or loose wires, etc. Service as necessary.
Install breakout box, leave PCM disconnected.
Measure resistance between Test Pin 46 at the breakout box and SIG RTN circuit at the MLP sensor vehicle harness connector.

Is resistance less than 5.0 ohms?

Yes	No
GO to TG102.	SERVICE open circuit. REMOVE breakout box. RECONNECT all components. RERUN Quick Test.

TG102 CHECK FOR SHORT TO POWER IN MLP SIG HARNESS CIRCUIT

Key off.
MLP sensor disconnected.
Breakout box installed, PCM disconnected.
Measure resistance between Test Pin 30 and Test Pins 37/57, 40/60 and 46 at the breakout box.

Is each resistance greater than 10,000 ohms?

Yes	No
GO to TG103.	SERVICE short circuit. REMOVE breakout box. RECONNECT all components. RERUN Quick Test.

TG103 CHECK MLP SENSOR RESISTANCE

Key off.
Connect MLP sensor.
Breakout box installed, PCM disconnected.
Unlock steering column.
Measure resistance between Test Pin 30 and Test Pin 46 at the breakout box in each gear selector position. Refer to the MLP sensor resistance specification table below:

Transmission Shift Position	Minimum (ohms)	Maximum (ohms)
Park	3770	4607
Reverse	1304	1593
Neutral	660	807
Overdrive	361	442
2/Drive*	190	232
First	78	95

* Drive for AX4S except SHO applications

Is each resistance within specification?

Yes	No
REPLACE the PCM. REMOVE the breakout box. RERUN Quick Test.	REPLACE MLP sensor. REMOVE breakout box. RERUN Quick Test.