Pinpoint Tests BG: DTC B19A4

Seats

Pinpoint Test BG: DTC B19A4

Refer to Wiring Diagram Set 119, Climate Controlled Seats for schematic and connector information. Diagrams By Number

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 blower is supplied operating voltage from PCSM-2 output circuit CHS67 (VT/BN) and ground from PCSM-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 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 and blower assembly
- PCSM-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.

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BG1 CHECK BACKREST TED BLOWER SPEED CONTROL CIRCUIT FOR A SHORT TO VOLTAGE

- Disconnect: PCSM-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.

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BG2 CHECK BACKREST TED BLOWER SPEED CONTROL CIRCUIT FOR A SHORT TO VOLTAGE

- Disconnect: Backrest TED 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.

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BG3 CHECK BACKREST TED BLOWER SPEED CONTROL AND BLOWER OUTPUT CIRCUITS FOR A SHORT TOGETHER

- Ignition OFF.
- Disconnect: Backrest TED C3362.
- Measure the resistance between PCSM-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.

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BG4 CHECK THE BACKREST TED RESISTANCE FOR AN INTERNAL SHORT

- Measure the resistance between backrest TED C3362 pin 2 and pin 7, component side.




- Is the resistance greater than 2M ohms?

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

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

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