Pinpoint Test BG: DTC B19A4

Seats

Pinpoint Test BG: DTC B19A4

Normal Operation

The Passenger Climate Controlled Seat Module - 2 (PCSM-2) supplies a speed control signal voltage to the LH rear seat backrest Thermo-Electric Device (TED) on circuit VHS68 (BN/GN). The TED (Thermo-Electric Device) blower is supplied operating voltage from PCSM-2 (Passenger Climate Controlled Seat Module - 2) output circuit CHS67 (VT/BN) and ground from PCSM-2 (Passenger Climate Controlled Seat Module - 2) output circuit RHS67 (WH/BU).

- DTC B19A4 (Driver Seat Back Blower Speed Short to Battery)- If the LH rear seat backrest blower speed circuit is shorted to voltage, the PCSM-2 (Passenger Climate Controlled Seat Module - 2) will shut down the LH rear seat system and set this DTC.

This pinpoint test is intended to diagnose the following:

- Wiring, terminals or connectors

- TED (Thermo-Electric Device) and blower assembly

- PCSM-2 (Passenger Climate Controlled Seat Module - 2)

PINPOINT TEST BG : DTC B19A4

NOTICE: When taking measurements at Passenger Climate Controlled Seat Module - 2 (PCSM-2) harness connectors, do not insert the electrical probes into the female connector pins. Inserting the probes into connector pins can cause intermittent or open electrical connections after reassembly resulting in Diagnostic Trouble Codes (DTCs) and system failure. Touching the tip of these connector pins is recommended instead.

BG1 CHECK BACKREST TED (Thermo-Electric Device) BLOWER SPEED CONTROL CIRCUIT FOR A SHORT TO VOLTAGE

- Disconnect: PCSM-2 (Passenger Climate Controlled Seat Module - 2) C3365C.

- Ignition ON.

- Measure the voltage between C3365C-12, circuit VHS68 (BN/GN), harness side and ground.




Is any voltage present?

Yes
GO to BG2.

No
GO to BG3.

BG2 CHECK BACKREST TED (Thermo-Electric Device) BLOWER SPEED CONTROL CIRCUIT FOR A SHORT TO VOLTAGE

- Disconnect: Backrest TED (Thermo-Electric Device) C3362.

- Measure the voltage between C3365C-12, circuit VHS68 (BN/GN), harness side and ground.




Is any voltage present?

Yes
REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.

No
GO to BG3.

BG3 CHECK BACKREST TED (Thermo-Electric Device) BLOWER SPEED CONTROL AND BLOWER OUTPUT CIRCUITS FOR A SHORT TOGETHER

- Ignition OFF.

- Disconnect: Backrest TED (Thermo-Electric Device) C3362.

- Measure the resistance between PCSM-2 (Passenger Climate Controlled Seat Module - 2) C3365C-12, circuit VHS68 (BN/GN), harness side and C3365C-16, circuit CHS67 (VT/BN), harness side.




Is the resistance greater than 10,000 ohms?

Yes
GO to BG4.

No
REPAIR the circuits. CLEAR the DTCs. REPEAT the self-test.

BG4 CHECK THE BACKREST TED (Thermo-Electric Device) RESISTANCE FOR AN INTERNAL SHORT

- Measure the resistance between backrest TED (Thermo-Electric Device) C3362 pin 2 and pin 7, component side.




Is the resistance greater than 2M ohms?

Yes
INSTALL a new PCSM-2 (Passenger Climate Controlled Seat Module - 2). REFER to Passenger Climate - Controlled Seat Module (PCSM-2) . CLEAR the DTCs. REPEAT the self-test.

No
INSTALL a new backrest TED (Thermo-Electric Device). REFER to Seat Backrest Thermo-Electric Device - Second Row . CLEAR the DTCs. REPEAT the self-test.