Diagnostic Routine K

Diagnostic Routine K

Diagnostic Overview

B10D7:87

Normal Operations and Fault Conditions

The BCM (Body Control Module) supplies voltage to the PATS (Passive Anti-Theft System) transceiver. When the START/STOP switch is pressed, the RFA (Remote Function Actuator) module searches the interior of the vehicle for a programmed IA (Intelligent Access) key. If an IA (Intelligent Access) key is not found, the BCM (Body Control Module) initiates the backup key interrogation sequence. The BCM (Body Control Module) starts the backup interrogation sequence by generating a signal and sending that signal to the transceiver on the transmit (TX) circuit. When the transceiver receives the signal from the BCM (Body Control Module), it reads the IA (Intelligent Access) key and generates a challenge response to the BCM (Body Control Module) signal. The transceiver sends the challenge response back to the BCM (Body Control Module) on the receive (RX) circuit.

DTC Fault Trigger Conditions






Visual Inspection and Diagnostic Pre-checks

- BCM (Body Control Module) fuse F59 (5A)

Pinpoint Test

1. CHECK THE PATS (Passive Anti-Theft System) TRANSCEIVER VOLTAGE SUPPLY CIRCUIT

1. Disconnect: PATS (Passive Anti-Theft System) transceiver.

2. Place an IA (Intelligent Access) key inside the vehicle and press the START/STOP switch.

3. Measure:





Is the voltage greater than 11 volts?






2. CHECK THE PATS (Passive Anti-Theft System) TRANSCEIVER CIRCUITS FOR A SHORT TO VOLTAGE

1. Ignition OFF.

2. Disconnect: BCM (Body Control Module) C2280C.

3. Disconnect: Ignition relay.

4. Connect:





5. Measure:





Is any voltage present?






3. CHECK THE PATS (Passive Anti-Theft System) TRANSCEIVER CIRCUITS FOR A SHORT TO GROUND

1. Ignition OFF.

2. Measure:





Are the resistances greater than 10,000 ohms?






4. CHECK THE PATS (Passive Anti-Theft System) TRANSCEIVER CIRCUITS FOR AN OPEN

1. Measure:





Are the resistances less than 3 ohms?






5. CHECK FOR CORRECT BCM (Body Control Module) OPERATION

1. Ignition OFF.

2. Disconnect and inspect all BCM (Body Control Module) connectors.

3. Repair:

- corrosion, (install new connectors 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 BCM (Body Control Module) connectors and make sure they seat and latch correctly.

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

Is the concern still present?