Diagnostic Routine K

Diagnostic Routine K

Diagnostic Overview

B2418, B2419 or B2420

Refer to Wiring Diagram Set 109 for schematic and connector information Electrical Diagrams.

Normal Operations and Fault Conditions

The LTM (Liftgate/Trunk Module) monitors the position sensor (internal to the power liftgate motor) for liftgate movement and velocity. It is primarily used for obstacle detection during power open and close operations. The LTM (Liftgate/Trunk Module) supplies a 5-volt reference voltage and ground to the sensor and monitors the sensor through the 2 sensor signal feedback circuits. The position sensor is a Hall-effect type sensor.

DTC Fault Trigger Conditions






Pinpoint Test

1. CHECK FOR VOLTAGE TO THE POSITION SENSOR

1. Ignition OFF.

2. Disconnect: Power Liftgate Motor.

3. Ignition ON.

4. Measure:





Is the voltage approximately 5 volts?








2. CHECK THE POSITION SENSOR VOLTAGE CIRCUIT

1. Measure:





Is the voltage approximately 5 volts?








3. CHECK THE POSITION SENSOR VOLTAGE CIRCUIT FOR AN OPEN OR SHORT TO GROUND

1. Ignition OFF.

2. Disconnect: LTM (Liftgate/Trunk Module) C4174B.

3. Measure:









Is the resistance less than 3 ohms between LTM (Liftgate/Trunk Module) and power liftgate motor; and greater than 10,000 ohms between LTM (Liftgate/Trunk Module) and ground?








4. CHECK THE POSITION SENSOR RETURN CIRCUIT FOR AN OPEN

1. Ignition OFF.

2. Disconnect: LTM (Liftgate/Trunk Module) C4174B.

3. Measure:





Is the resistance less than 3 ohms?








5. CHECK THE POSITION SENSOR CIRCUITS FOR REFERENCE VOLTAGE

1. Ignition ON.

2. Measure:





Are the voltages approximately 5 volts?








6. CHECK THE POSITION SENSOR CIRCUITS FOR AN OPEN

1. Ignition OFF.

2. Disconnect: LTM (Liftgate/Trunk Module) C4174B.

3. Measure:





Are the resistances less than 3 ohms?








7. CHECK THE POSITION SENSOR CIRCUITS FOR A SHORT TO VOLTAGE

1. Ignition ON.

2. Measure:





Is any voltage present?








8. CHECK THE POSITION SENSOR CIRCUITS FOR A SHORT TO GROUND

1. Measure:





Are the resistances greater than 10,000 ohms?








9. CHECK FOR CORRECT LTM (Liftgate/Trunk Module) OPERATION

1. Ignition OFF.

2. Disconnect and inspect all LTM (Liftgate/Trunk Module) connectors.

3. Repair:

- corrosion (install new connector or terminals - clean module pins)
- damaged or bent pins - install new terminals/pins
- pushed-out pins - install new pins as necessary

4. Reconnect all the LTM (Liftgate/Trunk Module) connectors. Make sure they seat and latch correctly.

5. Operate the system and determine if the concern is still present.

Is the concern still present?