Pinpoint Test I: The Power Lumbar is Inoperative - Passenger
Seats
Pinpoint Tests
Pinpoint Test I: 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 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 I: THE POWER LUMBAR IS INOPERATIVE - PASSENGER
NOTE: If a seat equipped with a seat mounted side air bag is being repaired, the Supplemental Restraint System (SRS) must be depowered. Refer to Supplemental Restraint System Supplemental Restraint System (SRS) Depowering and Repowering.
NOTE: The air bag warning lamp illuminates when the Restraints Control Module (RCM) fuse is removed and the ignition switch is ON. This is normal operation and does not indicate an SRS fault.
NOTE: The SRS must be fully operational and free of faults before releasing the vehicle to the customer.
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I1 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 I2.
No
GO to Pinpoint Test B to diagnose the inoperative seat. Pinpoint Test B: The Power Seat is Inoperative - Passenger
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I2 CHECK FOR VOLTAGE TO THE LUMBAR MOTOR
- Ignition OFF.
- Depower the SRS. Refer to Supplemental Restraint System Supplemental Restraint System (SRS) Depowering and Repowering.
- Disconnect: Passenger Seat Side Air Bag Module C339.
- 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, Mounting and Cables Battery Disconnect.
- NOTE: During the following step, the voltage being measured changes polarity dependent upon which direction the seat control switch is activated.
- 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, while operating the lumbar switch in both directions.
- Is the voltage greater than 10 volts when the lumbar 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 C339.
REPOWER the SRS. REFER to Supplemental Restraint System Supplemental Restraint System (SRS) Depowering and Repowering.
No
GO to I3.
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I3 CHECK THE LUMBAR MOTOR CIRCUITS FOR AN OPEN
- Disconnect: Passenger Seat Control Switch C330.
- Measure the resistance between:
- seat control switch C330-10, circuit CPS20 (VT), harness side and power lumbar motor C3216-B, circuit CPS18 (BN/GN), harness side.
- seat control switch C330-7, 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 Seat Control Switch. TEST the system for normal operation.
DISCONNECT the battery ground cable.
CONNECT passenger seat side air bag module C339.
REPOWER the SRS. REFER to Supplemental Restraint System Supplemental Restraint System (SRS) Depowering and Repowering.
No
REPAIR the circuit(s). TEST the system for normal operation.
DISCONNECT the battery ground cable.
CONNECT passenger seat side air bag module C339.
REPOWER the SRS. REFER to Supplemental Restraint System Supplemental Restraint System (SRS) Depowering and Repowering.
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