For 1990-2009 cars

## DTC B2494 Power Liftgate

### Diagnostic Instructions

• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

• | Review Strategy Based Diagnosis for an overview of the diagnostic approach.

• | Diagnostic Procedure Instructions provides an overview of each diagnostic category.

### DTC Descriptor

DTC B2494 02: Liftgate Handle Switch Circuit Short to Ground

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Liftgate Module B+ | 2 | B1019 00 | -- | --
Liftgate Position Sensor 5V Reference Voltage | 2 | B153E 08 | 2 | --
Full Open Signal | B153B 02 | 2 | 2 | --
Liftgate Disable Signal | 1, 2 | 1 | 1 | --
Liftgate Open Signal | 1 | 1 | 1 | --
Object Sensors Signal | B153F 03 | 2 | B153F 07 | --
Open/Close Switches Signal | B2494 02 | 1, 2 | 1, 2 | --
Pawl Switch Signal | B153A 00 | B153A 08 | B153A 00 | --
Position Sensor Signal 1 | B153E 02 | B153E 05, B153A 08 | B153E 05 | --
Position Sensor Signal 2 | B153E 02 | B153E 05, B153A 08 | B153E 05 | --
Ratchet Switch Signal | B153A 00 | B153A 00 | B153A 00 | --
Sector Switch Signal | B153A 00 | B153A 00 | B153A 00 | --
Disengage Clutch Control | B396B 02 | B396B 04 | B396B 01 | --
Engage Clutch Control | B396B 02 | B396B 04 | B396B 01 | --
Liftgate Latch Cinch Control | B2495 02 | B2495 04 | B2495 01 | --
Liftgate Latch Release Control | B2495 02 | B2495 04 | B2495 01 | --
Liftgate Motor Close Control | B396A 02 | B396A 04 | B396A 01 | --
Liftgate Motor Open Control | B396A 02 | B396A 04 | B396A 01 | --
Full Open Low Reference | -- | 2 | 2 | --
Liftgate Switches Low Reference | -- | 1 | 1 | --
Position Sensor Low Reference | -- | B0153E 08 | 2 | --
I/P Switch Ground | -- | 1 | 1 | --
Liftgate Control Module Ground | -- | 2 | 2 | --
1. Liftgate Switch Malfunction 2. Liftgate Malfunction

### Circuit/System Description

The power liftgate button and exterior liftgate handle switch are parallel circuits and provide a single input to the liftgate module (LGM). The liftgate switches are supplied voltage and share a common low reference circuit from the LGM. When the switch contacts close, the LGM detects the voltage drop and commands the liftgate to open or close depending upon the position of the liftgate at the time.

### Conditions for Running the DTC

The system voltage is 9-18 volts.

### Conditions for Setting the DTC

The Liftgate Open/Close Signal circuit is active for longer than 10 minutes.

### Action Taken When the DTC Sets

The liftgate open and close functions from the liftgate switches will be inoperative.

### Conditions for Clearing the DTC

• | The DTC will be current for as long as the fault is present.

• | When the fault is no longer present, the DTC will be a history DTC.

• | A history DTC will clear after 50 ignition cycles.

### Diagnostic Aids

Important: Before testing can be performed the liftgate must be opened. Refer to Opening the Liftgate Without Electrical Power for the appropriate procedure.

Whenever the LGM loses power or is disconnected, the ignition must be cycled OFF then ON in order to reactivate the LGM.

### Reference Information

#### Schematic Reference

Liftgate Schematics

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

Rear Hatch/Gate Description and Operation

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### Scan Tool Reference

Control Module References for scan tool information

### Circuit/System Verification

Ignition ON, observe the scan tool Liftgate Handle Sw. Status parameter while pressing and releasing the liftgate switches. The reading should change between Active and Inactive.

### Circuit/System Testing

1. Ignition OFF, disconnect the harness connectors at the liftgate exterior switch and liftgate interior switch.
2. Ignition ON, verify the scan tool Liftgate Handle Sw. Status parameter is Inactive.

⇒ | If not the specified value, test the signal circuit terminal 1 for a short to ground. If the circuit tests normal, replace the LGM.

3. Ignition OFF, connect the harness connector at the exterior liftgate switch.
4. Ignition ON, observe the scan tool Liftgate Handle Sw. Status parameter while pressing and releasing the exterior liftgate switch, the reading should change between Active and Inactive.

⇒ | If the parameter does not change, test or replace the exterior liftgate switch.

5. If all circuits test normal, test or replace the interior liftgate switch.

### Component Testing

1. Ignition OFF, disconnect the harness connector at the appropriate liftgate switch.
2. Test for infinite resistance between the signal terminal 1 and the low reference terminal 2 with the switch in the open position.

⇒ | If not the specified value, replace the liftgate switch.

3. Test for less than 2.0 ohms between the signal terminal 1 and the low reference terminal 2 with the switch in the closed position.

⇒ | If greater than the specified range, replace the liftgate switch.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for LGM replacement, setup, and programming

## DTC B2494 Manual Liftgate

### Diagnostic Instructions

• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

• | Review Strategy Based Diagnosis for an overview of the diagnostic approach.

• | Diagnostic Procedure Instructions provides an overview of each diagnostic category.

### DTC Descriptor

DTC B2494 00: Liftgate Handle Switch Circuit

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Liftgate Relay Switch B+ | 2 | 2 | -- | --
Liftgate Release Switch Signal | B2494 00 | B2494 00 | B2494 00 | --
Liftgate Relay Low Reference | -- | 2 | B3265 00 | --
Liftgate Relay Coil Control | B2495 02 | 2 | B2495 01 | --
Liftgate Latch Control | -- | 2 | 2 | --
Liftgate Latch Ground | -- | 2 | 2 | --
Liftgate Switch Ground | -- | 1 | 1 | --
1. Liftgate Release Switch Malfunction 2. Liftgate Release Malfunction

### Circuit/System Description

The liftgate release switch is an input to the body control module (BCM). The BCM supplies battery voltage to the signal circuit and when the release switch is activated the signal circuit voltage goes low. The BCM controls the liftgate release actuator through the liftgate latch release relay. When the release switch signal is activated, the BCM enables the liftgate latch release relay by applying battery voltage to the liftgate latch release relay supply circuit and the relay is energized when the BCM grounds the liftgate latch release relay control circuit. When the relay is energized battery voltage is supplied to the liftgate release actuator through the liftgate release actuator control circuit.

### Conditions for Running the DTC

The system voltage is 9-18 volts.

### Conditions for Setting the DTC

The liftgate release switch signal circuit is active for longer than 10 minutes.

### Action Taken When the DTC Sets

The liftgate latch will malfunction.

### Conditions for Clearing the DTC

• | The DTC will be current for as long as the fault is present.

• | When the fault is no longer present, the DTC will be a history DTC.

• | A history DTC will clear after 50 ignition cycles.

### Diagnostic Aids

Before testing can be performed the liftgate must be opened. Refer to Opening the Liftgate Without Electrical Power for the appropriate procedure.

### Reference Information

#### Schematic Reference

Release Systems Schematics

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

Rear Hatch/Gate Description and Operation

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### Scan Tool Reference

Control Module References for scan tool information

### Circuit/System Verification

Ignition ON, observe the scan tool Liftgate Handle Sw. parameter while pressing the exterior liftgate switch. The reading should change between Active and Inactive.

### Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the exterior liftgate switch.
2. Test for less than 1.0 ohm between the ground circuit terminal 2 and ground.

⇒ | If greater than the specified range, test the ground circuit for an open/high resistance.

3. Ignition ON, verify the scan tool Liftgate Handle Sw. parameter is Inactive.

⇒ | If not the specified value, test the signal circuit terminal 1 for a short to ground. If the circuit tests normal, replace the BCM.

4. Install a 3A fused jumper wire between the signal circuit terminal 1 and the ground circuit terminal 2. Verify the scan tool Liftgate Handle Sw. parameter is Active.

⇒ | If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.

5. If all circuits test normal, test or replace the exterior liftgate switch.

### Component Testing

1. Ignition OFF, disconnect the harness connector at the exterior liftgate switch.
2. Test for infinite resistance between the signal terminal 1 and the ground terminal 2 with the switch in the open position.

⇒ | If not the specified value, replace the exterior liftgate switch.

3. Test for less than 2.0 ohms between the signal terminal 1 and the ground terminal 2 with the switch in the closed position.

⇒ | If greater than the specified range, replace the exterior liftgate switch.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for BCM replacement, setup, and programming