Pinpoint Test C: The Power Seat is Inoperative - Passenger
Seats
Pinpoint Test C: The Power Seat is Inoperative - MKZ, Passenger
Refer to Wiring Diagram Set 120, Power Seats for schematic and connector information. [1][2]Diagrams By Number
Normal Operation
The passenger seat control switch is supplied voltage and ground. When the passenger seat control switch is activated, voltage and ground is supplied to the applicable seat track motor to move the seat to the desired position. There are 3 seat track motors that combine to move the seat cushion horizontally (forward/rearward) and vertically (front up/down and rear up/down). If a new motor on the seat track needs to be installed, it is necessary to install an entire seat track assembly. There is an additional motor in the seat recliner mechanism to move the seat backrest forward and rearward.
This pinpoint test is intended to diagnose the following:
- Fuse
- Wiring, terminals or connectors
- Seat control switch
PINPOINT TEST C : THE POWER SEAT IS INOPERATIVE - MKZ, PASSENGER
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.
C1 CHECK FOR VOLTAGE TO THE 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: Passenger Seat Side Air Bag Module C313.
- Disconnect: Passenger 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.
- Measure the voltage between passenger seat control switch C3190-5, circuit SBB31 (WH/RD), harness side and ground.
Is the voltage greater than 10 volts?
Yes
GO to C2.
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. TEST the system for normal operation. [1][2]Diagrams By Number
DISCONNECT the battery ground cable. CONNECT passenger seat side air bag module C313. REPOWER the SRS (Supplemental Restraint System). REFER to Restraints and Safety Systems &/or Air Bag Systems.
C2 CHECK FOR GROUND TO THE SEAT CONTROL SWITCH
- Measure the resistance between passenger seat control switch C3190-3, circuit GD126 (BK/WH), harness side and ground.
Is the resistance less than 5 ohms?
Yes
INSTALL a new passenger 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 (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 passenger seat side air bag module C313. REPOWER the SRS (Supplemental Restraint System). REFER to Restraints and Safety Systems &/or Air Bag Systems.