DTC B242A With Memory - A45
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 BatteryDTC B242A 02: Seat Heaters Common Circuit Short to Ground
Diagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Memory Seat Module B+ Terminal 5 | B2425 0D, B2430 0D, 1, 2 | B2425 0D, B2430 0D, 1, 2 | -- | -- |
Driver Heated Seat Element Control Terminal 11 X3 | B242A 02 | B2425 0D | B242A 01 | B2425 0E |
Driver Heated Seat Element Control Terminal 6 X3 | B242A 02 | B2425 0D | B242A 01 | B2425 0E |
Driver Heated Seat Temperature Sensor Signal | B1925 02 | B1925 05 | B1925 05 | -- |
Driver Heated Seat Temperature Sensor Low Reference | -- | B1925 05 | -- | -- |
Passenger Heated Seat Element Control Terminal 10 X3 | B242A 02 | B2430 0D | B242A 01 | B2430 0E |
Passenger Heated Seat Element Control Terminal 4 X3 | B242A 02 | B2430 0D | B242A 01 | B2430 0E |
Passenger Heated Seat Temperature Sensor Signal | B2170 02 | B2170 05 | B2170 05 | -- |
Passenger Heated Seat Temperature Sensor Low Reference | -- | B2170 05 | -- | -- |
1. Power seats inoperative 2. Heated seats inoperative | ||||
Circuit/System Description
The driver and passenger seat heating elements are controlled by a common low side relay internal to the memory seat module and by individual high side element control circuits. The module connects the heater element supply voltage circuits for both seats to a common reference point. This reference point is biased to approximately 2.5 V. Before the memory seat module will allow heated seat operation, it checks to see if this reference voltage is shorted to ground or voltage. Once the memory seat module verifies that it is not closing to a shorted heating element, it allows for heated seat operation. The memory seat module will then continue to monitor the heating elements for a shorted circuit.
Conditions for Running the DTC
| • | DTC B1325 must not be present. |
| • | The memory seat module must be powered. |
Conditions for Setting the DTC
B242A 01
The memory seat module detects a short to voltage on the heater element supply voltage circuit or control circuit.
B242A 02
The memory seat module detects a short to ground for on the heater element supply voltage circuit or control circuit.
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
Connector End View Reference
Description and Operation
Heated/Vented Seat Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Testing
- Ignition OFF, disconnect the X3 harness connector at the K40 memory seat module.
- Test for infinite resistance between the control circuit terminal 11 and ground.
- Test for infinite resistance between the control circuit terminal 10 and ground.
- Ignition ON, verify that a test lamp does not illuminate between the control circuit terminal 11 and ground.
- Verify that a test lamp does not illuminate between the control circuit terminal 10 and ground.
- If all circuits test normal, replace the K40 memory seat module.
| ⇒ | If not the specified value, test the control circuit for a short to ground. |
| ⇒ | If not the specified value, test the control circuit for a short to ground. |
| ⇒ | If the test lamp illuminates, test the control circuit for a short to voltage. |
| ⇒ | If the test lamp illuminates, test the control circuit for a short to voltage. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for memory seat module replacement, setup, and programming
DTC B242A Without Memory - A45
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 BatteryDTC 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 Temperature Sensor Signal | B1925 02 | B1925 05 | B1925 05 | -- |
Driver Heated Seat Temperature Sensor Low Reference | -- | B1925 05 | -- | -- |
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 Temperature Sensor Signal | B2170 02 | B2170 05 | B2170 05 | -- |
Passenger Heated Seat Temperature Sensor Low Reference | -- | B2170 05 | -- | -- |
Circuit/System Description
The driver and passenger seat heating elements are controlled by a common high current relay internal to the heated seat module and by individual low side element control circuits. The module connects the heated seat heater element supply voltage circuits for both seats to a common reference point. This reference point is biased to approximately 2.5 V. Before the heated seat module will allow heated seat operation, it checks to see if this reference voltage is shorted to ground or voltage. Once the heated seat module verifies that it is not closing to a shorted heating element, it allows for heated seat operation. The heated seat module will then continue to monitor the heating elements for a shorted circuit.
Conditions for Running the DTC
| • | DTC B1325 must not be present. |
| • | The heated seat module must be powered. |
Conditions for Setting the DTC
B242A 01
The heated seat module detects a short to voltage on the heater element supply voltage circuit or control circuit.
B242A 02
The heated seat module detects a short to ground for on the heater element supply voltage circuit or control circuit.
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
Connector End View Reference
Description and Operation
Heated/Vented Seat Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Testing
- Ignition OFF, disconnect the X2 harness connector at the K29 heated seat module.
- Test for infinite resistance between the control circuit terminal 3 and ground.
- Test for infinite resistance between the control circuit terminal 5 and ground.
- Ignition ON, verify that a test lamp does not illuminate between the control circuit terminal 3 and ground.
- Verify that a test lamp does not illuminate between the control circuit terminal 5 and ground.
- If all circuits test normal, replace the K29 heated seat module.
| ⇒ | If not the specified value, test the control circuit for a short to ground. |
| ⇒ | If not the specified value, test the control circuit for a short to ground. |
| ⇒ | If the test lamp illuminates, test the control circuit for a short to voltage. |
| ⇒ | If the test lamp illuminates, test the control circuit for a short to voltage. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for heated seat module replacement, setup, and programming
