Rear Seat
DTC B2345 (Rear Seat)
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.
DTC Descriptors
DTC B2345 00
- Seat Heater Disable Circuit
DTC B2345 13
- Seat Heater Disable Circuit Voltage Low / High Temperature
DTC B2345 42
- Seat Heater Disable Circuit Calibration Data Set Not Programmed
DTC B2345 4B
- Seat Heater Disable Circuit Calibration Not Learned
Diagnostic Fault Information
Circuit/System Description
The front seat heating elements are controlled by a common high current relay internal to the rear heated seat control module (RHSM) and on the low side by individual element control circuits. The RHSM connects the seat heater element supply voltage circuits to a common reference point. This reference point is biased to approximately 2.5 V. Before the RHSM 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. Once the RHSM verifies that it is not closing into a shorted heating element, it allows heated seat operation. After which it continues to monitor for a shorted circuit.
Conditions for Running the DTC
The RHSM must be powered.
Conditions for Setting the DTC
B2345 00
After a heated seat is activated, the RHSM detects a shorted circuit on the seat heating element supply voltage circuit or control circuit.
B2345 13
Any of the temperature sensor inputs remains below 1.45 V for more than 1 second.
B2345 42
The current sensing calibration is not programmed.
B2345 4B
The current sensing calibration is out of range.
Action Taken When the DTC Sets
The heated seat function for both 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.
Reference Information
Schematic Reference
Heated/Cooled Seat Schematics [1][2]Electrical Diagrams
Connector End View Reference
Component Connector End Views Connector Views
Description and Operation
Heated Seats Description and Operation (KA1) Heated Seats (KA1)Heated Seats Description and Operation (KA6) Heated Seats (KA6)
Electrical Information Reference
* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs
Scan Tool Reference
Control Module References Control Module References for scan tool information
Circuit/System Verification
Verify the type of vehicle and the heated seat system for which the DTC set.
If the DTC set in the rear heated seat module, refer to Circuit/System Testing below.
If the DTC set in a vehicle equipped with memory, refer to DTC B2345 (w/o HP2 with memory).
If the DTC set in a hybrid vehicle without memory, refer to DTC B2345 (HP2 w/o memory).
If the DTC set in a non-hybrid vehicle without memory, refer to DTC B2345 (Dealer Installed).
Circuit/System Testing
B2345 00
1. Ignition OFF, disconnect the X1 harness connector at the RHSM.
2. Test for infinite resistance between the control circuit terminal 3 and ground.
• If not the specified value, test the control circuits listed below for a short to ground:
* Left rear seat heater element terminal 3
* Left rear seat heater element terminal 5
3. Test for infinite resistance between the control circuit terminal 6 and ground.
• If not the specified value, test the control circuits listed below for a short to ground:
* Right rear seat heater element terminal 6
* Right rear seat heater element terminal 2
4. Ignition ON, verify that a test lamp does not illuminate between the control circuit terminal 3 and ground.
• If the test lamp illuminates, test the control circuits listed below for a short to voltage:
* Left rear seat heater element terminal 3
* Left rear seat heater element terminal 5
5. Verify that a test lamp does not illuminate between the supply voltage circuit terminal 6 and ground.
• If the test lamp illuminates, test the control circuits listed below for a short to voltage:
* Right rear seat heater element terminal 6
* Right rear seat heater element terminal 2
6. If all circuits test normal, replace the RHSM.
B2345 13
1. Ignition OFF, disconnect the X2, X4 harness connectors at the RHSM.
2. Test for greater than 850 ohms between the signal and the low reference circuits listed below:
* Left rear seat terminal 9 X4 and terminal 6 X2
* Right rear seat terminal 20 X4 and terminal 8 X2
• If less than the specified value, test for a short between the signal and low reference circuits. If the circuits test normal, replace the appropriate seat cushion heater element/temperature sensor.
3. If all circuits test normal, replace the RHSM.
B2345 42 or B2345 4B
If either DTC is set, replace the RHSM.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.
* Rear Seat Cushion Heater Replacement Rear Seat Cushion Heater Replacement
* Control Module References Control Module References for the RHSM replacement, setup, and programming