Component Tests and General Diagnostics

Rotunda TR/MLP Sensor Tester Overlay:

INTRODUCTION

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

The transmission tester allows a technician to operate the electrical portion of the transmission range (TR) sensor. The TR/MLP tester usage is divided into five steps:
1. Preliminary testing and diagnosis.
2. Transmission tester installation (Set-Up Procedure).
3. Testing TR sensor.
4. Park/Neutral, backup lamp and optional circuit voltage tests.
5. Transmission tester removal and clearing diagnostic trouble codes (DTCs).

PRELIMINARY TESTING AND DIAGNOSIS
Before any diagnostic testing is done on a vehicle, some preliminary checks must be performed as described 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 TR 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 diagnostics.
- Record all DTCs.
- Service all non-transmission DTCs.

INSTALLATION PROCEDURES

NOTE:
- Installing the Transmission Tester at the TR sensor CONNECTOR allows the separation of the vehicle electronics from the TR sensor electronics.
- 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.
- Powertrain Management and the electrical and vacuum diagrams should be referenced to assist in diagnosis of electronically-controlled transmissions:

1. Disconnect vehicle harness at TR sensor 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 TR/MLP sensor overlay onto tester. Connect interface cable Rotunda MLP-C Cable 007-001 2R or equivalent to transmission tester and then to the TR sensor connector.

NOTE: For in-vehicle testing, use the transmission tester extension cable.

CAUTION: Route all cables away from HEAT SOURCES to prevent damage to cables.

3. Turn test select switch to the TR/MLP SENSOR TEST position.
4. Plug transmission tester power supply plug into cigar lighter.

NOTE:
- At this time, all LEDs should illuminate for a short period and then turn off. This is the tester internal circuit check.
- Static testing procedures allow for shop testing of the transmission in the vehicle or on the bench. Completion of these tests prove out the TR sensor electronically.

RESISTANCE/CONTINUITY TESTS

CAUTION: For resistance checks, be sure that the tester selector switch is set to the TR/MLP SENSOR TEST position or damage to the ohmmeter may result.

1. Set ohmmeter to 1000 ohm range.
2. Connect the positive lead of the ohmmeter to the TR/MLP jack.
3. Connect the negative lead of the ohmmeter to the SIGRTN jack.
4. Move transmission range selector lever into each gear position.
5. Record resistance at each position. Refer to the following chart for values.
6. If out of range, refer to Pinpoint Test D.
PARK
Minimum: 3770 Ohms
Maximum: 4607 Ohms
REVERSE
Minimum: 1304 Ohms
Maximum: 1593 Ohms
NEUTRAL
Minimum: 660 Ohms
Maximum: 807 Ohms
OVERDRIVE*
Minimum: 361 Ohms
Maximum: 442 Ohms
SECOND/DRIVE**
Minimum: 190 Ohms
Maximum: 232 Ohms
MANUAL 1
Minimum: 78 Ohms
Maximum: 95 Ohms

* Same values for overdrive or O/D CANCEL (DRIVE) on electronically controlled transmissions. D and Drive (O/D Cancelled) are in the same transmission range selector lever position.
** Same values for SECOND (electronic transmission) or DRIVE on transmissions with a separate DRIVE and OVERDRIVE position.

VOLTAGE TESTS-PARK/NEUTRAL, BACKUP LAMP AND OPTIONAL CIRCUITS
1. Tester Select Switch to the TR/MLP SENSOR TEST position.

NOTE: LED will turn red when the circuit closes and turn OFF when the circuit is open.

2. Press and HOLD each button while moving the transmission range selector lever through EACH range.
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 TR sensor alignment and then retest. If the sensor fails, then replace.

DISCONNECTING THE TESTER
1. Disconnect transmission tester from the TR Sensor 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. Reinstall vehicle wiring harness. Verify connection by pulling up on the harness.
3. Disconnect transmission tester power lead from vehicle.
4. Erase all DTCs using the procedures in powertrain management.
5. Rerun On-Board Diagnostic Tests to receive a pass code.
6. Verify that the customer concern has been eliminated.