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 contains the lumbar button and when pressed, supplies battery voltage and ground to the power lumbar motor on circuits CPS18 (BN/GN) and CPS19 (GY/VT) to move the lumbar assembly in the desired direction.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Seat 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 OTHER SEAT CONTROL SWITCH FEATURES FOR CORRECT OPERATION
- Operate the seat horizontally and vertically.
- Does the seat operate horizontally and vertically?
Yes
GO to P2.
No
GO to Pinpoint Test J to diagnose the inoperative seat. Pinpoint Test J: The Power Seat Does Not Move Horizontally/Vertically/Recline - Passenger, With Power Recliner
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P2 CHECK FOR VOLTAGE TO THE LUMBAR MOTOR
- 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 Safety Belt Buckle Pretensioner C3050.
- Disconnect: Passenger Seat Side Air Bag C3052.
- Disconnect: Power Lumbar Motor C3216.
- 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.
- While toggling the power lumbar switch, measure the voltage between power lumbar motor C3216-B, circuit CPS18 (BN/GN), harness side and power lumbar motor C3216-A, circuit CPS19 (GY/VT), 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 Lumbar Assembly. TEST the system for normal operation.
DISCONNECT the battery ground cable. CONNECT passenger safety belt buckle pretensioner C3050.
CONNECT passenger seat side air bag module C3052.
REPOWER the SRS. REFER to Restraint Systems.
No
GO to P3.
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P3 CHECK THE LUMBAR MOTOR CIRCUITS FOR AN OPEN
- Disconnect: Passenger Seat Control Switch C3026.
- Measure the resistance between:
- seat control switch C3026-7, circuit CPS20 (VT), harness side and power lumbar motor C3216-B, circuit CPS18 (BN/GN), harness side.
- seat control switch C3026-10, circuit CPS21 (WH/OG), harness side and power lumbar motor C3216-A, circuit CPS19 (GY/VT), 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 safety belt buckle pretensioner C3050.
CONNECT passenger seat side air bag module C3052.
REPOWER the SRS. REFER to Restraint Systems.
No
REPAIR the circuit(s). TEST the system for normal operation.
DISCONNECT the battery ground cable. CONNECT passenger safety belt buckle pretensioner C3050.
CONNECT passenger seat side air bag module C3052.
REPOWER the SRS. REFER to Restraint Systems.
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