PRE-RELEASE
DTC B242A (With KA6)
| DTC B242A (With KA6) |
| 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 |
| Left Rear Heated Seat Element Control Terminal 3 X2 | B242A 02 | B2425 0D | B242A 01 | B2425 0E |
| Left Rear Heated Seat Element Control Terminal 1 X2 | B242A 02 | B2425 0D | B242A 01 | B2425 0E |
| Left Rear Heated Seat Temperature Sensor Signal | B1925 02 | B1925 05 | B1925 05 | B2345 13 |
| Left Rear Heated Seat Temperature Sensor Low Reference | - | B1925 05 | - | B2345 13 |
| Right Rear Heated Seat Element Control Terminal 5 X2 | B242A 02 | B2430 0D | B242A 01 | B2430 0E |
| Right Rear Heated Seat Element Control Terminal 2 X2 | B242A 02 | B2430 0D | B242A 01 | B2430 0E |
| Right Rear Heated Seat Temperature Sensor Signal | B2170 02 | B2170 05 | B2170 05 | B2345 13 |
| Right Rear Heated Seat Temperature Sensor Low Reference | - | B2170 05 | - | B2345 13 |
| Circuit/System Description |
The rear seat heating control module controls seat heating operation for both left and right rear seats. The heating elements are controlled 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 rear 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 will then continue to monitor the heating elements for a shorted circuit.
| Conditions for Running the DTC |
| • |
DTC B1325 must not be present.
|
|
| • |
The rear seat heating control module must be powered.
|
|
| Conditions for Setting the DTC |
B242A 01
The rear seat heating control module detects a short to voltage on the heater element control circuitsB242A 02
The rear 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 rear 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
Rear Heated Seats 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 |
| 1. |
Ignition OFF, disconnect the X2 harness connector at the K29R rear seat heating control module.
|
|
| 2. |
Test for infinite resistance between the control circuit terminal 3 and ground.
|
|
| 3. |
If not the specified value, test the control circuit for a short to ground.
|
|
| 4. |
Test for infinite resistance between the control circuit terminal 5 and ground.
|
|
| 5. |
If not the specified value, test the control circuit for a short to ground.
|
|
| 6. |
Ignition ON, verify that a test lamp does not illuminate between the control circuit terminal 3 and ground.
|
|
| 7. |
If the test lamp illuminates, test the control circuit for a short to voltage.
|
|
| 8. |
Verify that a test lamp does not illuminate between the control circuit terminal 5 and ground.
|
|
| 9. |
If the test lamp illuminates, test the control circuit for a short to voltage.
|
|
| 10. |
If all circuits test normal, replace the K29R rear seat heating control module.
|
|
| Repair Instructions |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for rear seat heating control module replacement, setup, and programming
