Pinpoint Test V: the Power Lumbar Is Inoperative - Passenger
Seats
Pinpoint Tests
Pinpoint Test V: The Power Lumbar is Inoperative - Passenger
Refer to Wiring Diagram Set 122, Power Lumbar Seats for schematic and connector information. Diagrams By Number
Normal Operation
The lumbar control switch is supplied voltage on circuit 566 (DG) and ground on circuit 57 (BK). The lumbar control switch toggles voltage and ground directly to the lumbar motor circuits 1094 (PK) and 1097 (BN). The lumbar motor tightens or relaxes a cable connected to the lumbar adjuster.
This pinpoint test is intended to diagnose the following:
- Circuit breaker
- Wiring, terminals or connectors
- Lumbar control switch
- Lumbar assembly
PINPOINT TEST V: THE POWER LUMBAR IS INOPERATIVE - PASSENGER
WARNING: Remove restraint system diagnostic tools from the vehicle prior to road testing. If tools are not removed, the supplemental restraint system (SRS) device may not deploy in a crash. Failure to follow this instruction may result in serious personal injury or death in a crash and possibly violate vehicle safety standards.
NOTE: The air bag warning indicator illuminates when the correct Restraints Control Module (RCM) fuse is removed and the ignition switch 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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V1 CHECK FOR VOLTAGE TO THE LUMBAR CONTROL SWITCH
- Ignition OFF.
- Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering in the General Procedures of Air Bag Systems.
- Disconnect: Passenger Seat Side Air Bag C316.
- Connect: Restraint System Diagnostic Tool 418-133 to Passenger Seat Side Air Bag C316.
- Disconnect: Passenger Lumbar Control Switch C331.
- 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.
- Measure the voltage between passenger lumbar control switch C331-2, circuit 566 (DG), harness side and ground.
- Is the voltage greater than 10 volts?
Yes
GO to V2.
No
VERIFY Battery Junction Box (BJB) fuse 15 (15A) is OK. If OK, REPAIR the circuit. If not OK, REFER to the Wiring Diagrams to identify the possible causes of the circuit short. TEST the system for normal operation.
DISCONNECT the battery ground cable. DISCONNECT the restraint system diagnostic tool from passenger seat side air bag C316. CONNECT passenger seat side air bag C316. REPOWER the SRS. REFER to Air Bag Systems.
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V2 CHECK CIRCUIT 57 (BK) FOR AN OPEN
- Measure the resistance between:
- passenger lumbar control switch C331-3, circuit 57 (BK), harness side and ground.
- passenger lumbar control switch C331-6, circuit 57 (BK), harness side and ground.
- Are the resistances less than 5 ohms?
Yes
GO to V3.
No
REPAIR the circuit. TEST the system for normal operation.
DISCONNECT the battery ground cable. DISCONNECT the restraint system diagnostic tool from passenger seat side air bag C316. CONNECT passenger seat side air bag C316. REPOWER the SRS. REFER to Air Bag Systems.
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V3 CHECK FOR VOLTAGE TO THE LUMBAR MOTOR
- Connect: Passenger Lumbar Control Switch C331.
- Disconnect: Passenger Lumbar Motor C336.
- Measure the voltage between passenger lumbar motor C336-2, circuit 1097 (BN) and C336-1, circuit 1094 (PK) while operating the passenger lumbar control switch in both directions.
- Is the voltage greater than 10 volts with the switch in both directions?
Yes
INSTALL a new passenger lumbar motor. REFER to Lumbar Motor Lumbar Motor. TEST the system for normal operation.
DISCONNECT the battery ground cable. DISCONNECT the restraint system diagnostic tool from passenger seat side air bag C316. CONNECT passenger seat side air bag C316. REPOWER the SRS. REFER to Air Bag Systems.
No
GO to V4.
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V4 CHECK CIRCUITS 1094 (PK) AND 1097 (BN) FOR A SHORT TO GROUND
- Disconnect: Passenger Lumbar Control Switch C331.
- Measure the resistance between:
- passenger lumbar control switch C331-1, circuit 1097 (BN), harness side and ground.
- passenger lumbar control switch C331-7, circuit 1094 (PK), harness side and ground.
- Are the resistances greater than 10,000 ohms?
Yes
GO to V5.
No
REPAIR the circuit(s). TEST the system for normal operation.
DISCONNECT the battery ground cable. DISCONNECT the restraint system diagnostic tool from passenger seat side air bag C316. CONNECT passenger seat side air bag C316. REPOWER the SRS. REFER to Air Bag Systems.
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V5 CHECK CIRCUITS 1094 (PK) AND 1097 (BN) FOR AN OPEN
- Measure the resistance between:
- passenger lumbar control switch C331-1, circuit 1097 (BN), harness side and passenger lumbar motor C336-2, circuit 1097 (BN), harness side.
- passenger lumbar control switch C331-7, circuit 1094 (PK), harness side and passenger lumbar motor C336-1, circuit 1094 (PK), harness side.
- Are the resistances less than 5 ohms?
Yes
INSTALL a new passenger lumbar control switch. REFER to Lumbar Control Switch Lumbar Control Switch. TEST the system for normal operation.
DISCONNECT the battery ground cable. DISCONNECT the restraint system diagnostic tool from passenger seat side air bag C316. CONNECT passenger seat side air bag C316. REPOWER the SRS. REFER to Air Bag Systems.
No
REPAIR the circuit(s). TEST the system for normal operation.
DISCONNECT the battery ground cable. DISCONNECT the restraint system diagnostic tool from passenger seat side air bag C316. CONNECT passenger seat side air bag C316. REPOWER the SRS. REFER to Air Bag Systems.
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