B2508 (Rear Seat)

DTC B2508 OR B2509(REAR SEAT)

DTC DESCRIPTOR

DTC B2508 01
Seat Heater Relay Circuit Shorted to Ground

DTC B2508 02
Seat Heater Relay Circuit Shorted to Battery or Open

DIAGNOSTIC FAULT INFORMATION




Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview

CIRCUIT/SYSTEM DESCRIPTION
The rear heated seat heating elements are controlled by a common high current relay internal to the rear heated seat module and on the low side by individual element control circuits. Before the heated seat module will allow heated seat operation, it checks to see if the heating element supply voltage circuits and control circuits are shorted to ground or battery voltage.

CONDITIONS FOR RUNNING THE DTC
The rear heated seat module must be powered.

CONDITIONS FOR SETTING THE DTC

B2508 02
Before the heated seats are activated, the heated seat module detects a short to ground on the seat heating element supply voltage circuit or control circuit.

B2508 01
Before the heated seats are activated, the heated seat module detects a short to battery voltage on the seat heating element supply voltage circuit or control circuit.

ACTION TAKEN WHEN THE DTC SETS
The heated seat function for both of the rear passenger seats will be disabled.

CONDITIONS FOR CLEARING THE DTC
- The current DTC clears when the malfunction is no longer present and the power mode changes to OFF then back to ACC or RUN.
- The history DTC will clear after 50 consecutive fault-free ignition cycles have occurred.

CIRCUIT/SYSTEM TESTING
1. Ignition OFF, disconnect the C1 harness connector at the heated seat module.
2. Test for infinite resistance between the left seat heating element supply voltage circuit terminal 3 and ground.
- If less than infinite resistance, test the supply voltage circuit and the seat cushion heating element control circuit for a short to ground.
3. Ignition ON, verify that a test lamp does not illuminate between the supply voltage circuit terminal 3 and ground.
- If the test lamp illuminates, test the supply voltage circuit and the seat cushion heating element control circuit for a short to voltage.
4. Test for infinite resistance between the right seat heating element supply voltage circuit terminal 6 and ground.
- If less than infinite resistance, test the supply voltage circuit and the seat cushion heating element control circuit for a short to ground.
5. Ignition ON, verify that a test lamp does not illuminate between the supply voltage circuit terminal 6 and ground.
- If the test lamp illuminates, test the supply voltage circuit and the seat cushion heating element control circuit for a short to voltage.
6. If all circuits test normal, replace the heated seat module.

REPAIR INSTRUCTIONS
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
- Rear Seat Cushion Heater Replacement
- Control Module References for the rear heated seat module replacement, setup, and programming Verification Tests Programming and Relearning