Pinpoint Test O: The Power Lumbar Is Inoperative
Seats
Pinpoint Tests
Pinpoint Test O: The Power Lumbar is Inoperative
Refer to Wiring Diagram Set 120, Power Seats for schematic and connector information. Diagrams By Number
Refer to Wiring Diagram Set 123, Memory Seats for schematic and connector information. Diagrams By Number
Normal Operation
The seat control switch is supplied battery voltage on circuit SBB14 (BN/RD) (power seat) or SBP01 (RD) (memory seat) and ground on circuit GD133 (BK). When the knob of the seat control switch is pressed, voltage and ground are supplied to the power lumbar motor. When pressing the lumbar knob in the opposite direction, the lumbar control switch reverses the polarity to the power lumbar motor, which moves the lumbar mechanism in the opposite direction.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Lumbar control switch
- Power lumbar motor assembly
PINPOINT TEST O: THE POWER LUMBAR IS INOPERATIVE
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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O1 CHECK CIRCUIT SBB14 (BN/RD) (POWER SEAT) OR SBP01 (RD) (MEMORY SEAT) FOR AN OPEN
- Ignition OFF.
- Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering in the General Procedures portion of Restraint Systems.
- Disconnect: Driver Seat Safety Belt Buckle Pretensioner C3201.
- Disconnect: Driver Seat Side Air Bag C3049.
- Disconnect: Seat Control Switch C352.
- 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.
- For power seat, measure the voltage between seat control switch C352-5, circuit SBB14 (BN/RD), harness side and ground.
- For memory seat, measure the voltage between seat control switch C352-5, circuit SBP01 (RD), harness side and ground.
- Is the voltage greater than 10 volts?
Yes
GO to O2.
No
VERIFY Battery Junction Box (BJB) fuse 14 (40A) (power seat) or Smart Junction Box (SJB) fuse 1 (20A) (memory seat) is OK. If OK, REPAIR the circuit. If not OK, REFER to the Wiring Diagrams to identify possible causes of the circuit short. TEST the system for normal operation. Diagrams By Number
DISCONNECT the battery ground cable.
CONNECT driver safety belt buckle and pretensioner C3201.
CONNECT driver seat side air bag module C3049.
REPOWER the SRS. REFER to Restraint Systems.
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O2 CHECK CIRCUIT GD133 (BK) FOR AN OPEN
- Measure the resistance between seat control switch C352-3, circuit GD133 (BK), harness side and ground.
- Is the resistance less than 5 ohms?
Yes
GO to O3.
No
REPAIR the circuit. TEST the system for normal operation.
DISCONNECT the battery ground cable.
CONNECT driver safety belt buckle and pretensioner C3201.
CONNECT driver seat side air bag module C3049.
REPOWER the SRS. REFER to Restraint Systems.
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O3 CHECK THE LUMBAR MOTOR
- Connect: Seat Control Switch C352.
- Disconnect: Power Lumbar Motor C366.
- Measure the voltage between power lumbar motor C366-1, circuit CPS18 (BN/WH), harness side and power lumbar motor C366-2, circuit CPS19 (GY/VT), harness side.
- Operate the seat control switch in both directions.
- Is the voltage greater than 10 volts in both directions?
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 driver safety belt buckle and pretensioner C3201.
CONNECT driver seat side air bag module C3049.
REPOWER the SRS. REFER to Restraint Systems.
No
GO to O4.
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O4 CHECK CIRCUITS CPS19 (GY/VT) AND CPS18 (BN/GN) FOR A SHORT TO GROUND
- Disconnect: Seat Control Switch C352.
- Measure the resistance between:
- seat control switch C352-7, circuit CPS19 (GY/VT), harness side and ground.
- seat control switch C352-10, circuit CPS18 (BN/GN), harness side and ground.
- Are the resistances greater than 10,000 ohms.
Yes
GO to O5.
No
REPAIR the circuit. TEST the system for normal operation.
DISCONNECT the battery ground cable.
CONNECT driver safety belt buckle and pretensioner C3201.
CONNECT driver seat side air bag module C3049.
REPOWER the SRS. REFER to Restraint Systems.
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O5 CHECK CIRCUITS CPS19 (GY/VT) AND CPS18 (BN/GN)/(BN/WH) FOR AN OPEN
- Measure the resistance between:
- seat control switch C352-10, circuit CPS18 (BN/GN), harness side and power lumbar motor C366-1, circuit CPS18 (BN/WH), harness side.
- seat control switch C352-7, circuit CPS19 (GY/VT), harness side and power lumbar motor C366-2, 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 driver safety belt buckle and pretensioner C3201.
CONNECT driver seat side air bag module C3049.
REPOWER the SRS. REFER to Restraint Systems.
No
REPAIR the circuit. TEST the system for normal operation.
DISCONNECT the battery ground cable.
CONNECT driver safety belt buckle and pretensioner C3201.
CONNECT driver seat side air bag module C3049.
REPOWER the SRS. REFER to Restraint Systems.
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