Pinpoint Test P: The Power Lumbar is Inoperative - Passenger
Seats
Pinpoint Tests
Pinpoint Test P: The Power Lumbar is Inoperative - Passenger
Refer to Wiring Diagram Set 120, Power Seats for schematic and connector information. Diagrams By Number
Normal Operation
The seat control switch is powered by battery voltage on circuit SBB61 (GY/RD) and is supplied ground on circuit GD145 (BK/BU). When the lumbar knob on the seat control switch is pressed, voltage and ground are supplied to the power lumbar motor. When pressing the lumbar knob in the opposite direction, the seat control switch reverses the polarity to the power lumbar motor, which moves the lumbar mechanism in the opposite direction.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Lumbar control switch
- Power lumbar motor assembly
PINPOINT TEST P: THE POWER LUMBAR IS INOPERATIVE - PASSENGER
NOTE: The air bag warning indicator illuminates when the correct Restraints Control Module (RCM) fuse is removed and the ignition is ON.
NOTE: The Supplemental Restraint System (SRS) must be fully operational and free of faults before releasing the vehicle to the customer.
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P1 CHECK CIRCUIT SBB61 (GY/RD) FOR AN OPEN
- Ignition OFF.
- Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering in the General Procedures portion of Restraint Systems.
- Disconnect: Passenger Seat Side Air Bag C327.
- WARNING: Make sure no one is in the vehicle and there is nothing blocking or placed in front of any air bag module when the battery is connected. Failure to follow these instructions may result in serious personal injury in the event of an accidental deployment.
- Connect the battery ground cable. Refer to Battery.
- Disconnect: Seat Control Switch C3026.
- Measure the voltage between seat control switch C3026-5, circuit SBB61 (GY/RD), harness side and ground.
- Is the voltage greater than 10 volts?
Yes
GO to P2.
No
VERIFY Battery Junction Box (BJB) fuse 61 (30A) is OK. If OK, REPAIR the circuit. If not OK, Refer to the Wiring Diagrams to identify possible causes of the circuit short. TEST the system for normal operation. Diagrams By Number
DISCONNECT the battery ground cable. CONNECT passenger seat side air bag module C327.
REPOWER the SRS. REFER to Restraint Systems.
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P2 CHECK CIRCUIT GD145 (BK/BU) FOR AN OPEN
- Measure the resistance between seat control switch C3026-3, circuit GD145 (BK/BU), harness side and ground.
- Is the resistance less than 5 ohms?
Yes
GO to P3.
No
REPAIR the circuit. TEST the system for normal operation.
DISCONNECT the battery ground cable. CONNECT passenger seat side air bag module C327.
REPOWER the SRS. REFER to Restraint Systems.
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P3 CHECK THE LUMBAR MOTOR
- Connect: Seat Control Switch C3026.
- Disconnect: Power Lumbar Motor C3216.
- While operating the seat control switch in both directions, measure the voltage between power lumbar motor C3216-1, circuit CPS20 (VT), harness side and power lumbar motor C3216-2, circuit CPS21 (WH/OG), harness side.
- Is the voltage greater than 10 volts when the seat control switch is operated in both directions and 0 volt in the rest position?
Yes
INSTALL a new power lumbar assembly. REFER to Lumbar Assembly - Power Lumbar Assembly - Power. TEST the system for normal operation.
DISCONNECT the battery ground cable. CONNECT passenger seat side air bag module C327.
REPOWER the SRS. REFER to Restraint Systems.
No
GO to P4.
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P4 CHECK CIRCUITS CPS20 (VT) AND CPS21 (WH/OG) FOR A SHORT TO GROUND
- Disconnect: Seat Control Switch C3026.
- Measure the resistance between:
- seat control switch C3026-10, circuit CPS20 (VT), harness side and ground.
- seat control switch C3026-7, circuit CPS21 (WH/OG), harness side and ground.
- Are the resistances greater than 10,000 ohms.
Yes
GO to P5.
No
REPAIR the circuit. TEST the system for normal operation.
DISCONNECT the battery ground cable. CONNECT passenger seat side air bag module C327.
REPOWER the SRS. REFER to Restraint Systems.
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P5 CHECK CIRCUITS CPS20 (VT) AND CPS21 (WH/OG) FOR AN OPEN
- Measure the resistance between:
- seat control switch C3026-10, circuit CPS20 (VT), harness side and power lumbar motor C3216-1, circuit CPS20 (VT), harness side.
- seat control switch C3026-7, circuit CPS21 (WH/OG), harness side and power lumbar motor C3216-2, circuit CPS21 (WH/OG), harness side.
- Are the resistances less than 5 ohms?
Yes
INSTALL a new seat control switch. REFER to Seat Control Switch - Front Seat Control Switch - Front. TEST the system for normal operation.
DISCONNECT the battery ground cable. CONNECT passenger seat side air bag module C327.
REPOWER the SRS. REFER to Restraint Systems.
No
REPAIR the circuit. TEST the system for normal operation.
DISCONNECT the battery ground cable. CONNECT passenger seat side air bag module C327.
REPOWER the SRS. REFER to Restraint Systems.
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