DTC B242A
Diagnostic Instructions
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
|
