Pinpoint Test U: The Power Lumbar Is Inoperative - Both Rear Seats
Seats
Pinpoint Tests
Pinpoint Test U: The Power Lumbar is Inoperative - Both Rear Seats
Refer to Wiring Diagram Set 120, Power Seats for schematic and connector information. Diagrams By Number
Refer to Wiring Diagram Set 123, Memory Seats for schematic and connector information. Diagrams By Number
Normal Operation
When the lumbar button is pressed, voltage and ground are supplied to the power lumbar motor to move the lumbar mechanism in or out.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Lumbar control switch
- Lumbar motor
PINPOINT TEST U: THE POWER LUMBAR IS INOPERATIVE - BOTH REAR SEATS
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U1 CHECK FOR VOLTAGE TO THE LUMBAR MOTOR
- Disconnect: LH Rear Power Lumbar Motor C3230.
- Measure voltage between power lumbar motor 3230-B, circuit CPS47 (WH), harness side and power lumbar motor C3230-A, circuit CPS46 (VT), harness side.
- Operate the seat control switch in both directions.
- Is the voltage greater than 10 volts in both directions?
Yes
INSTALL a new power lumbar assembly. REFER to Lumbar Assembly - Second Row Lumbar Assembly - Second Row. TEST the system for normal operation.
No
GO to U2.
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U2 CHECK THE LUMBAR MOTOR CIRCUITS FOR AN OPEN
- Disconnect: LH Rear Lumbar Control Switch C3356.
- Measure the resistance between:
- lumbar control switch C3356-3, circuit CPS47 (WH), harness side and power lumbar motor C3230-B, circuit CPS47 (WH), harness side.
- lumbar control switch C3356-7, circuit CPS46 (VT), harness side and power lumbar motor C3230-A, circuit CPS46 (VT), harness side.
- Are the resistances less than 5 ohms?
Yes
INSTALL a new lumbar control switch. REFER to Lumbar Control Switch - Second Row Lumbar Control Switch - Second Row. TEST the system for normal operation.
No
REPAIR the circuit(s). TEST the system for normal operation.
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