Pinpoint Test I: The Power Lumbar Is Inoperative - Driver
Seats
Pinpoint Tests
Pinpoint Test I: The Power Lumbar is Inoperative - Driver
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 and ground. The lumbar control switch toggles voltage and ground directly to the lumbar motor circuits. 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 I: THE POWER LUMBAR IS INOPERATIVE - DRIVER
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.
NOTICE: Use the correct probe adapter(s) from the Flex Probe Kit when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
NOTICE: Most faults are due to connector and/or wiring concerns. Carry out a thorough inspection and verification before proceeding with the pinpoint test. Inspection and Verification
NOTE: The SRS must be fully operational and free of faults before releasing the vehicle to the customer.
-------------------------------------------------
I1 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 portion of Supplemental Restraint System Supplemental Restraint System (SRS) Depowering and Repowering.
- Disconnect: Driver Seat Side Air Bag C315.
- Connect: Restraint System Diagnostic Service Tool to Driver Seat Side Air Bag C315.
- Disconnect: Lumbar Control Switch C361.
- 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.
- Measure voltage between lumbar control switch C361-2, circuit 517 (BK/WH), harness side and ground.
- Is the voltage greater than 10 volts?
Yes
GO to I2.
No
VERIFY the Battery Junction Box (BJB) circuit breaker 601 (20A) 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. Diagrams By Number
DISCONNECT the battery ground cable. DISCONNECT the restraint system diagnostic service tool from driver seat side air bag module C315. CONNECT driver seat side air bag module C315. REPOWER the SRS. REFER to Supplemental Restraint System Supplemental Restraint System (SRS) Depowering and Repowering.
-------------------------------------------------
I2 CHECK FOR GROUND TO THE LUMBAR CONTROL SWITCH
- Measure the resistance between:
- driver lumbar control switch C361-3, circuit 57 (BK), harness side and ground.
- driver lumbar control switch C361-6, circuit 57 (BK), harness side and ground.
- Are the resistances less than 5 ohms?
Yes
GO to I3.
No
REPAIR the circuit. TEST the system for normal operation.
DISCONNECT the battery ground cable. DISCONNECT the restraint system diagnostic service tool from driver seat side air bag module C315. CONNECT driver seat side air bag module C315. REPOWER the SRS. REFER to Supplemental Restraint System Supplemental Restraint System (SRS) Depowering and Repowering.
-------------------------------------------------
I3 CHECK THE VOLTAGE TO THE LUMBAR MOTOR
- Connect: Driver Lumbar Control Switch C361.
- Disconnect: Driver Lumbar Motor C366.
- Measure the voltage between driver lumbar motor C366-2, circuit 1097 (BN) and C366-1, circuit 1094 (PK), harness side while operating the driver lumbar control switch in both directions.
- Is the voltage greater than 10 volts with the switch in both directions?
Yes
INSTALL a new driver lumbar assembly. REFER to Lumbar Assembly [1][2]Lumbar Assembly. TEST the system for normal operation.
DISCONNECT the battery ground cable. DISCONNECT the restraint system diagnostic service tool from driver seat side air bag module C315. CONNECT driver seat side air bag module C315. REPOWER the SRS. REFER to Supplemental Restraint System Supplemental Restraint System (SRS) Depowering and Repowering.
No
GO to I4.
-------------------------------------------------
I4 CHECK THE LUMBAR MOTOR CIRCUITS FOR A SHORT TO GROUND
- Disconnect: Lumbar Control Switch C361.
- Measure the resistance between:
- driver lumbar control switch C361-1, circuit 1097 (BN), harness side and ground.
- driver lumbar control switch C361-7, circuit 1094 (PK), harness side and ground.
- Are the resistances greater than 10,000 ohms?
Yes
GO to I5.
No
REPAIR the circuit(s). TEST the system for normal operation.
DISCONNECT the battery ground cable. DISCONNECT the restraint system diagnostic service tool from driver seat side air bag module C315. CONNECT driver seat side air bag module C315. REPOWER the SRS. REFER to Supplemental Restraint System Supplemental Restraint System (SRS) Depowering and Repowering.
-------------------------------------------------
I5 CHECK THE LUMBAR MOTOR CIRCUITS FOR AN OPEN
- Measure the resistance between:
- driver lumbar control switch C361-1, circuit 1097 (BN), harness side and driver lumbar motor C366-2, circuit 1097 (BN), harness side.
- driver lumbar control switch C361-7, circuit 1094 (PK), harness side and driver lumbar motor C366-1, circuit 1094 (PK), harness side.
- Are the resistances less than 5 ohms?
Yes
INSTALL a new driver 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 service tool from driver seat side air bag module C315. CONNECT driver seat side air bag module C315. 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. DISCONNECT the restraint system diagnostic service tool from driver seat side air bag module C315. CONNECT driver seat side air bag module C315. REPOWER the SRS. REFER to Supplemental Restraint System Supplemental Restraint System (SRS) Depowering and Repowering.
-------------------------------------------------