Pinpoint Test P: The Power Lumbar Is Inoperative - Passenger

WARNING: This page is about a different car, the 2010 Mercury Milan, 2010 Lincoln MKZ, and 2010 Ford Fusion. However, it is still accessible from the selected car via links, so may be relevant.

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.

P1 CHECK FOR VOLTAGE TO THE SEAT CONTROL SWITCH
- Ignition OFF.
- Depower the SRS . Refer to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEPOWERING AND REPOWERING .
- 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, MOUNTING AND CABLES .
- Measure the voltage between seat control switch C3190-5, circuit SBB31 (WH/RD), harness side and ground.
  
  Fig 1: Measuring Voltage Between Seat Control Switch C3190-5, Circuit SBB31 (WH/RD), Harness Side And Ground
  Courtesy of FORD MOTOR CO.
- 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 appropriate SYSTEM WIRING DIAGRAMS article to identify the possible causes of the circuit short. TEST the system for normal operation.
DISCONNECT the battery ground cable.

CONNECT passenger seat side air bag module C313. REPOWER the SRS . REFER to GENERAL PROCEDURES

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.
  
  Fig 2: Measuring Resistance Between Seat Control Switch C3190-3, Circuit GD139 (BK/YE), Harness Side And Ground
  Courtesy of FORD MOTOR CO.
- 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 GENERAL PROCEDURES

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.
  
  Fig 3: Checking For Voltage To Lumbar Motor
  Courtesy of FORD MOTOR CO.
- 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 . TEST the system for normal operation.
DISCONNECT the battery ground cable. CONNECT passenger seat side air bag module C313. REPOWER the SRS . REFER to GENERAL PROCEDURES
No : GO to P4.

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.
  Fig 4: Checking Lumbar Motor Circuits For Short To Ground
  Courtesy of FORD MOTOR CO.
- 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 GENERAL PROCEDURES

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.
  Fig 5: Checking Lumbar Motor Circuits For Open
  Courtesy of FORD MOTOR CO.
- Are the resistances less than 5 ohms?

Yes : INSTALL a new seat control switch. REFER to 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 GENERAL PROCEDURES
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 GENERAL PROCEDURES