Pinpoint Test P: The Power Lumbar Is Inoperative - Passenger

Seats

Pinpoint Tests

Pinpoint Test P: The Power Lumbar is Inoperative - Passenger

Refer to Wiring Diagram Set 120 (Fusion/Milan/MKZ, Fusion Hybrid/Milan Hybrid), Power Seats for schematic and connector information. Diagrams By Number

Normal Operation

The seat control switch is supplied battery voltage on circuit SBP31 (WH/RD) and ground on circuit GD139 (BK/YE). When the lumbar button (part of seat control switch) is pressed, voltage and ground are supplied to the power lumbar motor to move the lumbar mechanism in or out.

This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Lumbar control switch
- Lumbar motor



PINPOINT TEST P: THE POWER LUMBAR IS INOPERATIVE - PASSENGER

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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P1 CHECK FOR VOLTAGE TO THE SEAT CONTROL SWITCH


- Ignition OFF.
- Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering in the
General Procedures portion of Restraint Systems.
- Disconnect: Passenger Seat Side Air Bag Module C313 .
- Disconnect: Seat Control Switch C3190 .
- 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.
- Measure the voltage between seat control switch C3190-5, circuit SBB31 (WH/RD), harness side and ground.




- Is the voltage greater than 10 volts?

Yes
GO to P2.

No
VERIFY Battery Junction Box (BJB) fuse 31 (30A) is OK. If OK, REPAIR the circuit. If not OK, REFER to the Wiring Diagrams to identify the possible causes of the circuit short Diagrams By Number. TEST the system for normal operation.

DISCONNECT the battery ground cable. CONNECT passenger seat side air bag module C313. REPOWER the SRS. REFER to Restraint Systems.

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P2 CHECK FOR GROUND TO THE SEAT CONTROL SWITCH


- Measure the resistance between seat control switch C3190-3, circuit GD139 (BK/YE), harness side and ground.




- Is the resistance less than 5 ohms?

Yes
GO to P3.

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

DISCONNECT the battery ground cable. CONNECT passenger seat side air bag module C313. REPOWER the SRS. REFER to Restraint Systems.

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P3 CHECK FOR VOLTAGE TO THE LUMBAR MOTOR


- Connect: Seat Control Switch C3190 .
- Disconnect: Power Lumbar Motor C3216 .
- Measure the voltage between power lumbar motor C3216-1, circuit CPS20 (VT), harness side and power lumbar motor C3216-2, circuit CPS21 (WH/OG), 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 passenger seat side air bag module C313. REPOWER the SRS. REFER to Restraint Systems.

No
GO to P4.

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P4 CHECK THE LUMBAR MOTOR CIRCUITS FOR A SHORT TO GROUND


- Disconnect: Seat Control Switch C3190 .
- Measure the resistance between:
- seat control switch C3190-7, circuit CPS20 (VT), harness side and ground.
- seat control switch C3190-10, circuit CPS21 (WH/OG), harness side and ground.




- Are the resistances greater than 10,000 ohms.

Yes
GO to P5.

No
REPAIR the circuit(s). TEST the system for normal operation.

DISCONNECT the battery ground cable. CONNECT passenger seat side air bag module C313. REPOWER the SRS. REFER to Restraint Systems.

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P5 CHECK THE LUMBAR MOTOR CIRCUITS FOR AN OPEN


- Measure the resistance between:
- seat control switch C3190-7, circuit CPS20 (VT), harness side and power lumbar motor C3215-1, circuit CPS20 (VT), harness side.
- seat control switch C3190-10, circuit CPS21 (WH/OG), harness side and power lumbar motor C3215-2, circuit CPS21 (WH/OG), 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 passenger seat side air bag module C313. REPOWER the SRS. REFER to Restraint Systems.

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

DISCONNECT the battery ground cable. CONNECT passenger seat side air bag module C313. REPOWER the SRS. REFER to Restraint Systems.

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