Workshop Manuals Factory service & repair Vauxhall
Vauxhall Astra J16 · Seats
16 · Body & interior

DTC B242A

Make
Vauxhall
Model
Astra J
Section
Seat Heating and Cooling › Other Information › DTC B242A
SeatsDTC B242A

DTC B242A

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 B242A 01: Seat Heaters Common Circuit Short to Battery
DTC B242A 02: Seat Heaters Common Circuit Short to Ground

Diagnostic Fault Information



Circuit
Short to Ground
Open/High Resistance
Short to Voltage
Signal Performance

Driver Heated Seat Element Control Terminal 3 X2
B242A 02
B2425 0D
B242A 01
B2425 0E

Driver Heated Seat Element Control Terminal 1 X2
B242A 02
B2425 0D
B242A 01
B2425 0E

Driver Heated Seat Cushion Temperature Sensor Signal
B1925 02
B1925 05
B1925 05
B2345 13

Driver Heated Seat Cushion Temperature Sensor Low Reference
-
B1925 05
-
B2345 13

Passenger Heated Seat Element Control Terminal 5 X2
B242A 02
B2430 0D
B242A 01
B2430 0E

Passenger Heated Seat Element Control Terminal 2 X2
B242A 02
B2430 0D
B242A 01
B2430 0E

Passenger Heated Seat Cushion Temperature Sensor Signal
B2170 02
B2170 05
B2170 05
B2345 13

Passenger Heated Seat Cushion Temperature Sensor Low Reference
-
B2170 05
-
B2345 13
 

Circuit/System Description

The seat heating control module controls the seat heating operation for both the driver and front passenger seats. The module controls the heating elements through individual high side and low side control circuits. The low side control circuits for both seats are connected to a common reference point internal to the module. This reference point is biased to approximately 2.5 V. Before the seat heating control module will allow heated seat operation, it checks to see if this biased voltage is shorted to ground or voltage. Once the module verifies that it is not closing to a shorted heating element, it allows for heated seat operation. The module then continues to monitor the heating elements for a shorted circuit.

Conditions for Running the DTC

•  DTC B1325 must not be present.
•  The seat heating control module must be powered.

Conditions for Setting the DTC

B242A 01

The seat heating control module detects a short to voltage on the heater element control circuits.

B242A 02

The seat heating control module detects a short to ground on the heater element control circuits.

Action Taken When the DTC Sets

The heated seat function for both seats will be disabled.

Conditions for Clearing the DTC

•  The current DTC will clear and set a history code 3 seconds after the reference voltage returns to normal operating range and the ignition is cycled OFF then back to ACC or RUN.
•  The history DTC will clear after 40 consecutive fault-free ignition cycles have occurred.

Reference Information


Schematic Reference

Heated/Cooled Seat Schematics


Connector End View Reference

Component Connector End Views


Description and Operation

Heated Seats Description and Operation


Electrical Information Reference


Scan Tool Reference

Control Module References for scan tool information

Circuit/System Testing

1. Ignition OFF, disconnect the X2 harness connector at the K29 seat heating control module.
2. Test for infinite resistance between the control circuit terminal 3 and ground.
⇒ If not the specified value, test the control circuit for a short to ground.
3. Test for infinite resistance between the control circuit terminal 5 and ground.
⇒ If not the specified value, test the control circuit for a short to ground.
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 circuit for a short to voltage.
5. Verify that a test lamp does not illuminate between the control circuit terminal 5 and ground.
⇒ If the test lamp illuminates, test the control circuit for a short to voltage.
6. If all circuits test normal, replace the K29 seat heating control module.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for seat heating control module replacement, programming and setup

Parts & tools for this job For Vauxhall Astra

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