Pinpoint Test M: The Power Lumbar Is Inoperative - Passenger

WARNING: This page is about a different car, the 2014 Lincoln MKX and 2014 Ford Edge. However, it is still accessible from the selected car via links, so may be relevant.

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 SUPPLEMENTAL RESTRAINT SYSTEM .

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 fault.

NOTE: The SRS must be fully operational and free of faults before releasing the vehicle to the customer.

M1 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 C327.
- WARNING: Make sure no one is in the vehicle and there is nothing blocking or placed in front of any airbag 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 .
- Disconnect: Passenger Seat Control Switch C3026.
- Measure the voltage between passenger seat control switch C3026-5 , circuit SBB42 (YE/RD), harness side and ground.
  
  Fig 1: Measuring Voltage Between Passenger Seat Control Switch (C3026-5), Circuit SBB42 (YE/RD), Harness Side And Ground
  Courtesy of FORD MOTOR CO.
Is the voltage greater than 10 volts?
- Yes : GO to M2 .
- No : VERIFY Battery Junction Box (BJB) fuse 42 (30A) is OK. If OK, REPAIR the circuit. If not OK, REFER to the SYSTEM WIRING DIAGRAMS to identify possible causes of the circuit short. TEST the system for normal operation.
  DISCONNECT the battery ground cable. CONNECT passenger seat side air bag module C327.
  
  REPOWER the SRS . REFER to SUPPLEMENTAL RESTRAINT SYSTEM .
M2 CHECK THE SEAT CONTROL SWITCH GROUND FOR AN OPEN
- Measure the resistance between passenger seat control switch C3026-3 , circuit GD145 (BK/BU), harness side and ground.
  
  Fig 2: Measuring Resistance Between Passenger Seat Control Switch (C3026-3), Circuit GD145 (BK/BU), Harness Side And Ground
  Courtesy of FORD MOTOR CO.
Is the resistance less than 5 ohms?
- Yes : GO to M3 .
- No : REPAIR the circuit. TEST the system for normal operation.
  DISCONNECT the battery ground cable. CONNECT passenger seat side air bag module C327.
  
  REPOWER the SRS . REFER to SUPPLEMENTAL RESTRAINT SYSTEM .
M3 CHECK THE POWER LUMBAR MOTOR
- Connect: Passenger Seat Control Switch C3026.
- Disconnect: Power Lumbar Motor C3216.
- 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 C3216-1 , circuit CPS88 (GY/OG), harness side and power lumbar motor C3216-2 , circuit CPS89 (BU/BN), harness side.
  
  Fig 3: Measuring Voltage Between Power Lumbar Motor (C3216-1), Circuit CPS88 (GY/OG) And Power Lumbar Motor (C3216-2), Circuit CPS89 (BU/BN)
  Courtesy of FORD MOTOR CO.
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 passenger seat side air bag module C327.
  
  REPOWER the SRS . REFER to SUPPLEMENTAL RESTRAINT SYSTEM .
- No : GO to M4 .
M4 CHECK THE LUMBAR MOTOR CIRCUITS FOR A SHORT TO GROUND
- Disconnect: Passenger Seat Control Switch C3026.
- Measure the resistance between:
  - passenger seat control switch C3026-10 , circuit CPS88 (GY/OG), harness side and ground.
  - passenger seat control switch C3026-7 , circuit CPS89 (BU/BN), harness side and ground.
    
    Fig 4: Measuring Resistance Between Passenger Seat Control Switch (C3026-10), Circuit CPS88 (GY/OG), Harness Side And Ground
    Courtesy of FORD MOTOR CO.
Are the resistances greater than 10, 000 ohms .
- Yes : GO to M5 .
- No : REPAIR the circuit. TEST the system for normal operation.
  DISCONNECT the battery ground cable. CONNECT passenger seat side air bag module C327.
  
  REPOWER the SRS . REFER to SUPPLEMENTAL RESTRAINT SYSTEM .
M5 CHECK THE POWER LUMBAR MOTOR CIRCUITS FOR AN OPEN
- Measure the resistance between:
  - passenger seat control switch C3026-10 , circuit CPS88 (GY/OG), harness side and power lumbar motor C3216-1 , circuit CPS88 (GY/OG), harness side.
  - passenger seat control switch C3026-7 , circuit CPS89 (BU/BN), harness side and power lumbar motor C3216-2 , circuit CPS89 (BU/BN), harness side.
    
    Fig 5: Measuring Resistance Between Passenger Seat Control Switch (C3026-10), Circuit CPS88 (GY/OG) And Power Lumbar Motor (C3216-1), Circuit CPS88 (GY/OG)
    Courtesy of FORD MOTOR CO.
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 passenger seat side air bag module C327.
  
  REPOWER the SRS . REFER to SUPPLEMENTAL RESTRAINT SYSTEM .
- No : REPAIR the circuit. TEST the system for normal operation.
  DISCONNECT the battery ground cable. CONNECT passenger seat side air bag module C327.
  
  REPOWER the SRS . REFER to SUPPLEMENTAL RESTRAINT SYSTEM .