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Home >> Mercury >> 1994 >> Sable V6-182 3.0L >> Repair and Diagnosis >> Transmission and Drivetrain >> Transmission Control Systems >> Testing and Inspection >> Component Tests and General Diagnostics >> AX4N >> TR/MLP Sensor Testing

TR/MLP Sensor Testing

TR Sensor Tester Overlay:





CAUTION: Do not attempt to pry off connector with a screwdriver. This will damage the connector and could result in a transaxle concern.

The Transmission Tester allows you to test the TR sensor independent of the vehicle electronics.
TR sensor testing is divided into five steps:
1. Preliminary testing and diagnosis.
2. Install the Transmission Tester.
3. Testing the TR sensor.
4. Testing the Park/Neutral and Backup Circuits
5. Removing the Transmission Tester and clearing Diagnostic Trouble codes (DTCs).

Transmission Tester Use for TR Sensor Diagnosis

Installing the Transmission Tester at the transmission connector allows the separation of the TR Sensor electronics from the vehicle electronics.

Testing may cause additional Diagnostic Trouble Codes (DTCs) to be set. Therefore, it is important that you erase all DTCs whenever you make repairs. To verify elimination of all DTCs, rerun On-Board Diagnostics.






The Transmission Reference Manual should be available to assist in diagnosis of electronically controlled transmissions.

Preliminary Testing and Diagnosis
Before you start testing, perform the following Preliminary Checks. Be sure to write down your findings, especially any DTCs, for future reference.
1. Know and understand the customer's concern.
2. Verify that TR sensor is properly adjusted in NEUTRAL.
3. Verify customer concern (e.g. when does it occur?):
- Upshift
- Downshift
- Coasting
- Engagement
If concern involves noise or vibration, does it relate to any of the following:
- RPM
- Vehicle speed
- Shift
- Gear
- Range
- Temperature
4. Vehicle must be at normal operating temperature.
5. Check transmission fluid level and condition.
6. Check for the following items:
- Vehicle modifications.
- Electronic add-on items.
- Leaks.
- Proper linkage adjustments.
7. Check TSBs for related information.
8. Perform complete On-Board Diagnostics (OBD) for both KOEO and KOER.
9. Record all DTCs.
10. Repair all non-transmission DTCs.

Transmission Tester Installation (Set-Up Procedure)
1. Disconnect vehicle harness at transmission TR sensor.
2. Set the two-way switch in the down position. (This switch will stay in the same position for all TR sensor testing.)
3. Attach the TR/MLP Sensor overlay to the Transmission Tester.
Affixing the overlay will immobilize the two-way switch (set in Step 2)so it cannot be accidentally moved to an incorrect setting during testing.
4. Select and connect interface cable B to Tester and then to TR connector.
Use the Transmission Tester Extender Cable when running tests with the transaxle on the vehicle.

CAUTION: Route all cables away from heat sources to prevent damage to cables during testing.

5. Turn large dial to TR/MLP SENSOR TEST.









6. Plug Transmission Tester Power Cable into cigar lighter socket.
All LEDs should light for a short period and then turn off. This is the Tester's internal circuit check.

Testing (TR) Sensor
Static testing procedures allow for shop testing of the TR sensor on the vehicle or on the bench. Completion of these tests prove out the TR sensor electronically.

CAUTION: For resistance checks be sure that the LARGE DIAL is set to TR/MLP SENSOR TEST or damage to the ohmmeter could result.

Resistance/Continuity Tests
1. Using a digital volt-ohmmeter and the Transmission Tester, perform Pinpoint Test D as outlined or Transmission Reference Manual based on the DTC displayed.
2. Perform repairs as indicated by the pinpoint test. Always erase all codes, retest and road test vehicle after a repair.

TR Sensor Resistance Tests
1. Set ohmmeter to 20k ohms.
2. Connect ohmmeter COM jack to SIG RTN jack.
3. Connect ohmmeter POS lead to TR jack. LED turns OFF when circuit is open.
4. Record resistance in every gear position while moving the shift lever to each position.
5. Refer to table.
6. If values are out of range, refer to Pinpoint Test D.

Voltage Tests-Park/Neutral, Backup Lamp and Optional Circuits

Note: LED lights RED when circuit is closed.

LED turns off when circuit is open.
1. Press and hold each test button while moving the shift lever to each gear position.
2. Monitor each STATUS LED:
The LED in the appropriate gear position you are retesting should light RED.
If the LED for the applicable gear position fails to light RED, or if it lights for a position other than the gear selected:
- Verify TR alignment.
- Retest.

3. If the sensor fails, replace it. After you finish testing, continue to Transmission Tester Removal and Clearing DTCs.

Transmission Tester, Removal and Clearing DTCs

CAUTION: Do not attempt to pry off connectors with a screwdriver. This will damage the connector and could result in a transaxle concern.

1. Disconnect transmission tester from transaxle connector.
2. Reinstall vehicle wiring harness. Verify connection by pulling up on the harness.
3. Reinstall all heat shields that were previously removed.
4. Disconnect transmission tester power cable from vehicle.
5. Erase all DTCs.
6. Rerun On-Board Diagnostics (OBD) to receive a pass code (111).
7. Verify that the customer concern has been eliminated
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