Pinpoint Test J: The Power Lumbar Is Inoperative - Passenger
Seats
Pinpoint Test J: 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 battery voltage on circuit 517 (BK/WH). When the lumbar control switch is toggled in one direction, battery voltage is applied directly to a compressor in the seat backrest lumbar assembly from circuit 1094 (PK). The lumbar compressor is connected directly to ground circuit 57 (BK). When voltage is applied to the compressor motor from the lumbar control switch, air is pumped into the lumbar bladder expanding the backrest foam pad. Toggling the switch to the opposite position applies voltage to a solenoid valve coil in the compressor from circuit 1097 (BN) to release air from the lumbar bladder and the backrest foam pad relaxes.
This pinpoint test is intended to diagnose the following:
- Circuit breaker
- Wiring, terminals or connectors
- Lumbar control switch
- Lumbar assembly
PINPOINT TEST J: 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.
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
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J1 CHECK THE LUMBAR COMPRESSOR OPERATION
- Operate the switch to inflate the lumbar.
- Does the lumbar compressor operate?
Yes
GO to J2.
No
GO to J3.
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J2 CHECK FOR AIRFLOW FROM THE LUMBAR COMPRESSOR
- Disconnect the air hose from the lumbar compressor fitting.
- Operate the switch to inflate the lumbar and check for air from the compressor fitting.
- Is air blowing from the lumbar compressor fitting?
Yes
CHECK the hoses for leaks, disconnection or obstruction. REPAIR as necessary. If the hoses are OK, INSTALL a new lumbar assembly. REFER to Lumbar Assembly Lumbar Assembly. TEST the system for normal operation.
DISCONNECT the battery ground cable. DISCONNECT the restraint system diagnostic service tool from passenger seat side air bag module C316. CONNECT passenger seat side air bag module C316. REPOWER the Supplemental Restraint System (SRS). REFER to Air Bag Systems.
No
INSTALL a new lumbar assembly. REFER to Lumbar Assembly Lumbar Assembly. TEST the system for normal operation.
DISCONNECT the battery ground cable. DISCONNECT the restraint system diagnostic service tool from passenger seat side air bag module C316. CONNECT passenger seat side air bag module C316. REPOWER the SRS. REFER to Air Bag Systems.
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J3 CHECK CIRCUIT 517 (BK/WH) FOR VOLTAGE
- Ignition OFF.
- Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering in the General Procedures portion of Air Bag Systems.
- Disconnect: Passenger Seat Side Air Bag C316.
- Connect: Restraint System Diagnostic Service Tool to Passenger Seat Side Air Bag C316.
- Disconnect: 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 voltage between lumbar control switch C331-2, circuit 517 (BK/WH), harness side and ground.
- Is the voltage greater than 10 volts?
Yes
GO to J4.
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.
DISCONNECT the battery ground cable. DISCONNECT the restraint system diagnostic service tool from passenger seat side air bag module C316. CONNECT passenger seat side air bag module C316. REPOWER the SRS. REFER to Air Bag Systems.
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J4 CHECK CIRCUIT 57 (BK) FOR AN OPEN
- Disconnect: Lumbar Motor C336.
- Measure resistance between lumbar motor C336-3, circuit 57 (BK), harness side and ground.
- Is the resistance less than 5 ohms?
Yes
GO to J5.
No
REPAIR the circuit. TEST the system for normal operation.
DISCONNECT the battery ground cable. DISCONNECT the restraint system diagnostic service tool from passenger seat side air bag module C316. CONNECT passenger seat side air bag module C316. REPOWER the SRS. REFER to Air Bag Systems.
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J5 CHECK VOLTAGE TO THE LUMBAR MOTOR
- Connect: Lumbar Control Switch.
- Measure voltage between lumbar motor C336-1, circuit 1094 (PK), harness side and C336-3, circuit 57 (BK), harness side while pressing the lumbar control switch inflate button.
- Measure voltage between lumbar motor C336-2, circuit 1097 (BN), harness side and C336-3, circuit 57 (BK), harness side while pressing the lumbar control switch deflate button.
- Are the voltages greater than 10 volts?
Yes
INSTALL a new lumbar assembly. REFER to Lumbar Assembly Lumbar Assembly. TEST the system for normal operation.
DISCONNECT the battery ground cable. DISCONNECT the restraint system diagnostic service tool from passenger seat side air bag module C316. CONNECT passenger seat side air bag module C316. REPOWER the SRS. REFER to Air Bag Systems.
No
GO to J6.
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J6 CHECK CIRCUITS 1094 (PK) AND 1097 (BN) FOR AN OPEN
- Disconnect: Lumbar Control Switch C331.
- Measure resistance between:
- lumbar control switch C331-1, circuit 1094 (PK), harness side and lumbar motor C336-1, circuit 1094 (PK), harness side.
- lumbar control switch C331-3, circuit 1094 (PK), harness side and lumbar motor C336-1, circuit 1094 (PK), harness side.
- Measure resistance between lumbar control switch C331-7, circuit 1097 (BN), harness side and lumbar motor C336-2, circuit 1097 (BN), harness side.
- Are the resistances less than 5 ohms?
Yes
GO to J7.
No
REPAIR the circuit(s). TEST the system for normal operation.
DISCONNECT the battery ground cable. DISCONNECT the restraint system diagnostic service tool from passenger seat side air bag module C316. CONNECT passenger seat side air bag module C316. REPOWER the SRS. REFER to Air Bag Systems.
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J7 CHECK CIRCUITS 1094 (PK) AND 1097 (BN) FOR A SHORT TO GROUND
- Measure resistance between:
- lumbar motor C336-1, circuit 1094 (PK), harness side and ground.
- lumbar motor C336-2, circuit 1097 (BN), harness side and ground.
- Are the resistances greater than 10,000 ohms?
Yes
GO to J8.
No
REPAIR the circuit(s). TEST the system for normal operation.
DISCONNECT the battery ground cable. DISCONNECT the restraint system diagnostic service tool from passenger seat side air bag module C316. CONNECT passenger seat side air bag module C316. REPOWER the SRS. REFER to Air Bag Systems.
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J8 CHECK CIRCUITS 1094 (PK) AND 1097 (BN) FOR A SHORT TO VOLTAGE
- Ignition ON.
- Measure voltage between:
- lumbar motor C336-1, circuit 1094 (PK), harness side and ground.
- lumbar motor C336-2, circuit 1097 (BN), harness side and ground.
- Is voltage present on either circuit?
Yes
REPAIR the circuit(s). TEST the system for normal operation.
DISCONNECT the battery ground cable. DISCONNECT the restraint system diagnostic service tool from passenger seat side air bag module C316. CONNECT passenger seat side air bag module C316. REPOWER the SRS. REFER to Air Bag Systems.
No
INSTALL a new 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 passenger seat side air bag module C316. CONNECT passenger seat side air bag module C316. REPOWER the SRS. REFER to Air Bag Systems.
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