Diesel Data: Automotive Repair

Pinpoint Test L: The Power Lumbar Is Inoperative - Driver




Seats

Pinpoint Test L: The Power Lumbar is Inoperative - Driver

Refer to Wiring Diagram Set 123, Memory Seats for schematic and connector information Electrical Diagrams.

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 L : THE POWER LUMBAR IS INOPERATIVE - DRIVER

NOTE: If a seat equipped with a seat mounted side air bag is being serviced, the Supplemental Restraint System (SRS) must be depowered. Refer to Restraints and Safety Systems &/or Air Bag Systems.

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 (Supplemental Restraint System) fault.

NOTE: The SRS (Supplemental Restraint System) must be fully operational and free of faults before releasing the vehicle to the customer.

L1 CHECK FOR VOLTAGE TO THE POWER SEAT CONTROL SWITCH

- Ignition OFF.

- Depower the SRS (Supplemental Restraint System). Refer to Supplemental Restraint System (SRS) Depowering and Repowering in the General Procedures portion of Restraints and Safety Systems &/or Air Bag Systems.

- Disconnect: Driver Seat Side Air Bag C328.

- Disconnect: Driver Seat Control Switch C3016.

- 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 C3016-5, circuit SBB23 (WH/RD) (without memory seat) or SBP07 (WH/RD) (with memory seat), harness side and ground.






Is the voltage greater than 10 volts?

Yes
GO to L2.

No
VERIFY Body Control Module (BCM) fuse 7 (7.5A) (with memory seat) or Battery Junction Box (BJB) fuse 23 (30A) (without 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 Electrical Diagrams. TEST the system for normal operation.

DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C328.

REPOWER the SRS (Supplemental Restraint System). REFER to Restraints and Safety Systems &/or Air Bag Systems.

L2 CHECK THE POWER SEAT CONTROL SWITCH GROUND FOR AN OPEN

- Measure the resistance between driver seat control switch C3016-3, circuit GD145 (BK/BU), harness side and ground.






Is the resistance less than 5 ohms?

Yes
GO to L3.

No
REPAIR the circuit. TEST the system for normal operation.

DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C328.

REPOWER the SRS (Supplemental Restraint System). REFER to Restraints and Safety Systems &/or Air Bag Systems.

L3 CHECK FOR VOLTAGE TO THE POWER LUMBAR MOTOR

- Connect: Driver Seat Control Switch C3016.

- Disconnect: Power Lumbar Motor C3215.

- NOTE: During the following step, the voltage being measured changes polarity dependent upon which direction the seat control switch is activated.
While operating the seat control switch in both directions, measure the voltage between power lumbar motor C3215-1, circuit CPS19 (GY/VT), harness side and power lumbar motor C3215-2, circuit CPS18 (BN/GN), harness side.







Is the voltage greater than 10 volts when the seat control switch is operated and 0 volt in the rest position?

Yes
INSTALL a new power lumbar assembly. REFER to Lumbar Assembly - Power . TEST the system for normal operation.

DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C328.

REPOWER the SRS (Supplemental Restraint System). REFER to Restraints and Safety Systems &/or Air Bag Systems.

No
GO to L4.

L4 CHECK THE POWER LUMBAR MOTOR CIRCUITS FOR A SHORT TO GROUND

- Disconnect: Driver Seat Control Switch C3016.

- Measure the resistance between:
- driver seat control switch C3016-10, circuit CPS19 (GY/VT), harness side and ground.

- driver seat control switch C3016-7, circuit CPS18 (BN/GN), harness side and ground.







Are the resistances greater than 10,000 ohms?

Yes
GO to L5.

No
REPAIR the circuit. TEST the system for normal operation.

DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C328.

REPOWER the SRS (Supplemental Restraint System). REFER to Restraints and Safety Systems &/or Air Bag Systems.

L5 CHECK THE LUMBAR MOTOR CIRCUITS FOR AN OPEN

- Measure the resistance between:
- seat control switch C3016-10, circuit CPS19 (GY/VT), harness side and power lumbar motor C3215-1, circuit CPS19 (GY/VT), harness side.

- seat control switch C3016-7, circuit CPS18 (BN/GN), harness side and power lumbar motor C3215-2, circuit CPS18 (BN/GN), harness side.







Are the resistances less than 5 ohms?

Yes
INSTALL a new seat control switch. REFER to Seat Control Switch - Front . TEST the system for normal operation.

DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C328.

REPOWER the SRS (Supplemental Restraint System). REFER to Restraints and Safety Systems &/or Air Bag Systems.

No
REPAIR the circuit. TEST the system for normal operation.

DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C328.

REPOWER the SRS (Supplemental Restraint System). REFER to Restraints and Safety Systems &/or Air Bag Systems.