DTC B1388 or B1389
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 Descriptors DTC B1388 Left Rear Seat Haptic Movement Motor Control DTC B1389 Right Rear Seat Haptic Movement Motor Control For symptom byte information, refer to Symptom Byte List. Diagnostic Fault Information
| Circuit Number | Circuit Function | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performan |
|---|---|---|---|---|---|
| 3037 | Control | B1388 11 | 1 | B1388 12 | — |
| 3038 | Control | B1389 11 | 2 | B1389 12 | — |
| 1150 | Ground | — | 1, 2 | — | — |
| 1. P45LR Front Seat Lane Departure Warning Actuator - Left Rear is inoperative 2. P45RR Front Seat Lane Departure Warning Actuator - Right Rear is inoperative |
Circuit/System Description When the park assist, lane keep assist, or forward collision alert system detect a possible collision, the safety alert seat pulses on the left, right or both sides of the seat to alert drivers to the direction of the possible danger. The safety alert seats uses the P45LR Front Seat Lane Departure Warning Actuator - Left Rear and P45RR Front Seat Lane Departure Warning Actuator - Right Rear, located in the driver seat cushion, to provide haptic pulses. These are DC motors with an attached counterweight that creates a vibration when active. The K40D Driver Seat Adjuster Memory Module controls the P45LR Front Seat Lane Departure Warning Actuator - Left Rear and P45RR Front Seat Lane Departure Warning Actuator - Right Rear. Each P45 Front Seat Lane Departure Warning Actuator receives a constant ground on circuit 1150. The K40D Driver Seat Adjuster Memory Module controls each P45 Front Seat Lane Departure Warning Actuator by applying a PWM voltage on circuit 3037 for the P45LR Front Seat Lane Departure Warning Actuator - Left Rear or circuit 3038 for the P45RR Front Seat Lane Departure Warning Actuator - Right Rear. Conditions for Running the DTC Ignition ON Conditions for Setting the DTC B1388 11 Circuit 3037 is shorted to ground B1388 12 Circuit 3037 is shorted to ground B1389 11 Circuit 3038 is shorted to voltage B1389 12 Circuit 3038 is shorted to voltage Action Taken When the DTC Sets The safety alert seat is inoperative. Conditions for Clearing the DTC The condition for setting the DTC is no longer present. Reference Information Schematic Reference Driver Assistance Systems Schematics Connector End View Reference Master Electrical Component List Description and Operation Safety Alert Seat 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 Testing
- Ignition OFF, disconnect the X3 connector at the K40D Driver Seat Adjuster Memory Module.
- Verify the P45LR Front Seat Lane Departure Warning Actuator - Left Rear and P45RR Front Seat Lane Departure Warning Actuator - Right Rear are inactive and not vibrating. ⇒ If the P45LR Front Seat Lane Departure Warning Actuator - Left Rear is active and vibrating Repair the short to voltage on circuit 3037. ⇒ If the P45RR Front Seat Lane Departure Warning Actuator - Right Rear is active and vibrating Repair the short to voltage on circuit 3038. ⇓ If both P45 Front Seat Lane Departure Warning Actuators are inactive and not vibrating
- Connect a 3 A fused jumper wire between control circuit terminal 6 and B+.
- Verify the P45LR Front Seat Lane Departure Warning Actuator - Left Rear is active and vibrating. ⇒ If the P45LR Front Seat Lane Departure Warning Actuator - Left Rear is inactive and not vibrating 4.1. Test circuit 1150 for an open/high resistance. ⇒ If an open/high resistance is found, repair the fault on the circuit or ground connection. ⇓ If an open/high resistance is not found 4.2. Test circuit 3037 for a short to ground. ⇒ If a short to ground is found, repair the fault on the circuit. ⇓ If a short to ground is not found 4.3. Test circuit 3037 for an open/high resistance. ⇒ If an open/high resistance is found, repair the fault on the circuit. ⇓ If an open/high resistance is not found 4.4. Replace the P45LR Front Seat Lane Departure Warning Actuator - Left Rear ⇓ If the P45LR Front Seat Lane Departure Warning Actuator - Left Rear is active and vibrating
- Remove the jumper wire.
- Connect a 3 A fused jumper wire between control circuit terminal 5 and B+.
- Verify the P45RR Front Seat Lane Departure Warning Actuator - Right Rear is active and vibrating. ⇒ If the P45RR Front Seat Lane Departure Warning Actuator - Right Rear is inactive and not vibrating 7.1. Test circuit 1150 for an open/high resistance. ⇒ If an open/high resistance is found, repair the fault on the circuit or ground connection. ⇓ If an open/high resistance is not found 7.2. Test circuit 3038 for a short to ground. ⇒ If a short to ground is found, repair the fault on the circuit. ⇓ If a short to ground is not found 7.3. Test circuit 3038 for an open/high resistance. ⇒ If an open/high resistance is found, repair the fault on the circuit. ⇓ If an open/high resistance is not found 7.4. Replace the P45RR Front Seat Lane Departure Warning Actuator - Right Rear. ⇓ If the P45RR Front Seat Lane Departure Warning Actuator - Right Rear is active and vibrating
- Replace the K40D Driver Seat Adjuster Memory Module. Repair Instructions Perform the Diagnostic Repair Verification after completing the repair. Driver Assistance Systems Component Replacement Reference Control Module References for control module replacement, programming, and setup.