MLP Sensor Testing
MLP Sensor Testing - Enhancement (007-00086)
MLP Tester Instructions:
Transmission Tester Use For MLP Diagnosis
The Transmission Tester allows a technician to operate the electrical portion of the Manual Lever Position Sensor.
The MLP Tester usage is divided into five steps:
1. Preliminary Testing and Diagnosis.
2. Installing the Transmission Tester.
3. Testing the MLP Sensor.
4. Testing the Park/Neutral and Backup circuits.
5. Removing the Transmission Tester and Clearing Diagnostic Trouble Codes (DTCs).
Step 1
Preliminary Testing and Diagnosis
Before any diagnostic testing is done on a vehicle, some preliminary checks must be performed as outlined below. Be sure to write down your findings, especially any DTCs found, for future reference.
- Check transmission fluid level and condition.
- Check for add-on items (phones, computers, CB radio etc).
- Visually inspect wiring harness and connectors.
- Check for vehicle modifications.
- Verify that the shift linkage is properly adjusted in OVERDRIVE.
- Verify that MLP Sensor is properly adjusted in NEUTRAL.
- Verify customer concern.
Upshift, Downshift, Coasting, Engagement, Noise/Vibration
- Vehicle must be at a normal operating temperature.
- Perform vehicle On-Board Diagnostic.
- Record all DTCs.
- Service all non-transaxle DTCs.
Step 2
Transmission Tester Installation (Set Up Procedure)
Installing the Transmission Tester at the MLP Sensor CONNECTOR allows the separation of the vehicle electronics from the MLP sensor electronics.
Note: During tester usage additional DTCs may be set. Therefore, it is important that all codes are erased after service has been made. To verify elimination of all DTCs, rerun On-Board Diagnostic.
1. Disconnect vehicle harness at transmission MLP connector.
CAUTION: Do not attempt to pry off connectors with a screwdriver. This will damage the connector and could result in a transmission concern.
2. Set Bench/Drive switch to DRIVE mode.
Install MLP Sensor Overlay onto tester.
Connect interface cable to transmission tester and then to the MLP sensor connector.
Refer to chart for the proper cable/application.
NOTE: For in vehicle testing use the transmission tester extension cable.
CAUTION: Route all cables away from HEAT SOURCES.
3. Turn test select switch to the MLP SENSOR TEST position.
4. Plug transmission tester power supply plug into cigar lighter.
At this time, all LEDs should illuminate for a short period and then turn off. This is the tester internal circuit check.
Step 3
Testing MLP Sensor
Static testing procedures allow for shop testing of the transmission in the vehicle or on the bench. Completion of these tests prove out the MLP sensor electronically.
CAUTION: For resistance checks, be sure that the tester selector switch is set to the "MLP SENSOR TEST" position or damage to the ohmmeter may result.
Resistance/Continuity Tests
- Using a digital volt/ohmmeter and the Transmission Tester to perform Pinpoint Test D as indicated in the Service Manual or Transmission Reference Manual based on the DTCs which were displayed.
- Perform services as indicated by the pinpoint tests. Always retest and road test vehicle after any service.
MLP Sensor Resistance Tests
- Set ohmmeter to 1000 ohm range.
- Connect the positive lead of the ohmmeter to the MLP jack.
- Connect the negative lead of the ohmmeter to the SIGRTN jack.
- Move transmission range selector lever into each gear position.
- Record resistance at each position.
- Refer to the chart shown for values.
If out of range refer to Pinpoint Test D.
Step 4
Park/Neutral, Backup Lamp and Optional Circuit Voltage Tests
Note: LED will turn RED when the circuit closes and turn OFF when the circuit is open.
1. Turn Tester Select Switch to the MLP SENSOR TEST position.
2. Press and HOLD each button while moving the Transmission Range Selector Lever through EACH Gear position.
3. Monitor each LED.
4. The status LED should indicate RED only in the indicated position. Refer to overlay.
5. If the LED does NOT indicate RED in the desired position, or indicates RED in another position, first verify MLP alignment and then retest. If the sensor fails then replace.
Step 5
Transmission Tester Removal and Clearing DTCs
1. Disconnect transmission tester from the MLP Sensor connector.
CAUTION: Do not attempt to pry off connectors with a screwdriver. This will damage the connector and could result in a transaxle concern.
2. Reinstall vehicle wiring harness. Verify connection by pulling up on the harness.
3. Disconnect transmission tester power lead from vehicle.
4. Erase all DTCs. (Unlatch center button of SUPER STAR Tester II while codes are being displayed on a KOEO Self-Test).
5. Rerun On-Board Diagnostic Tests to receive a pass code (11 or 111).
6. Verify that the customer concern has been eliminated.