Pinpoint Test Q: Left Rear Seat Does Heat But the Heated Seat Indicator Does Not Illuminate

Seats

Pinpoint Test Q: The Heated Seat Does Not Operate Correctly - Left Rear Seat Does Heat But the Heated Seat Indicator Does Not Illuminate When Pressed

Normal Operation

Pressing the left rear heated seat switch once in either the high or low mode will command on the left rear heated seat. Voltage is then supplied to the left rear heated seat switch from the heated seat module on either circuit CHS48 (YE) (high heat mode) or circuit CHS49 (VT) (low heat mode) to illuminate the switch indicator. Pressing the left rear heated seat switch again in the mode that is currently on will set the left rear heated seat to off and also turn that LED off.

A new heated seat module must be configured after installation for correct operation. To configure, press the low heat mode button on either rear heated seat switch. Module configuration will occur automatically after the low heat mode button is pressed. Until the module is correctly configured, the heated seats will operate incorrectly when selecting the high heat mode by following a sequence of high, low and off with each button press. The system will operate correctly after the heated seat module receives a low heat request on either of the low heat request circuits and rear heated seat module configuration is activated.

This pinpoint test is intended to diagnose the following:

- Wiring, terminals or connectors

- Heated seat switch

- Heated seat module

PINPOINT TEST Q : THE HEATED SEAT DOES NOT OPERATE CORRECTLY - LEFT REAR SEAT DOES HEAT BUT THE HEATED SEAT INDICATOR DOES NOT ILLUMINATE WHEN PRESSED

Q1 CHECK CIRCUITS CHS49 (VT) AND CHS48 (YE) FOR A SHORT TO GROUND

- Disconnect: Left Rear Heated Seat Switch C320.

- Disconnect: Heated Seat Module C3304a.

- Measure the resistance between:
- heated seat module C3304A-4, circuit CHS49 (VT), harness side and ground.

- heated seat module C3304A-5, circuit CHS48 (YE), harness side and ground.






Are the resistances greater than 10,000 ohms?

Yes
GO to Q2.

No
REPAIR the affected circuit. TEST the system for normal operation.

Q2 CHECK CIRCUITS CHS49 (VT) AND CHS48 (YE) FOR AN OPEN

- Measure the resistance between:
- left rear heated seat switch C320-4, circuit CHS49 (VT), harness side and heated seat module C3304A-4, circuit CHS49 (VT), harness side.

- left rear heated seat switch C320-3, circuit CHS48 (YE), harness side and heated seat module C3304A-5, circuit CHS48 (YE), harness side.






Are the resistances less than 5 ohms?

Yes
GO to Q3.

No
REPAIR the affected circuit. TEST the system for normal operation.

Q3 CHECK THE HEATED SEAT HIGH INDICATOR

- Connect: Left Rear Heated Seat Switch C320.

- Ignition ON.

- Connect a fused jumper lead between heated seat module C3304A-5, circuit CHS48 (YE), harness side and C3304B-1, circuit SBP18 (YE/RD), harness side.





Does the high indicator LED illuminate on the left rear heated seat switch?

Yes
GO to Q4.

No
INSTALL a new rear heated seat switch. REFER to Heated Seat Switch - Rear . TEST the system for normal operation.

Q4 CHECK THE HEATED SEAT LOW INDICATOR

- Connect a fused jumper lead between heated seat module C3304A-4, circuit CHS49 (VT), harness side and C3304B-1, circuit SBP18 (YE/RD), harness side.





Does the low indicator LED illuminate on the left rear heated seat switch?

Yes
INSTALL a new heated seat module. REFER to Heated Seat Module - Rear . TEST the system for normal operation.

No
INSTALL a new rear heated seat switch. REFER to Heated Seat Switch - Rear . TEST the system for normal operation.