Pinpoint Test M: The Heated Seat Is Inoperative - Passenger, Does Not Operate In High

WARNING: This page is about a different car, the 2010 Lincoln Town Car. However, it is still accessible from the selected car via links, so may be relevant.

WARNING: Remove restraint system diagnostic tools from the vehicle prior to road testing. If tools are not removed, the supplemental restraint system (SRS) device may not deploy in a crash. Failure to follow this instruction may result in serious personal injury or death in a crash and possibly violate vehicle safety standards.

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.

NOTE: If a passenger seat cushion heater mat is inoperative, a new Occupant Classification Sensor (OCS) system service kit must be installed and a new cushion heater mat must be installed to the OCS system service kit foam pad.

NOTE: When installing an OCS system service kit equipped with heated seats, a new seat cushion heater mat must be installed. Do not reuse the OEM OCS cushion heater mat. The OCS system service kit does not come with a cushion heater mat.

M1 CHECK HEATED SEAT SWITCH INPUT RESISTANCE TO THE HEATED SEAT MODULE
- Key in OFF position.
- Depower the SRS. Refer to GENERAL PROCEDURES article.
- Disconnect: Passenger Seat Side Air Bag C316
- Connect: Restraint System Diagnostic Tool 418-133 to Passenger Seat Side Air Bag C316
- Disconnect: Heated Seat Module C681
- Measure resistance between heated seat module C681-14, circuit 581 (RD), harness side and ground while pressing the heated seat switch.
- Is resistance less than 50 ohms when the heated seat switch is pressed and greater than 10,000 ohms when the heated seat switch is not pressed?
1. YES : INSTALL a new heated seat module. REFER to Heated Seat Module - Front Seat . TEST the system for normal operation.
  DISCONNECT the battery ground cable. DISCONNECT the restraint system diagnostic tool from passenger seat side air bag C316. CONNECT passenger seat side air bag C316. REPOWER the SRS. REFER to GENERAL PROCEDURES article.
2. NO : Go to M2.
M2 CHECK CIRCUITS 581 (RD) AND 1020 (DG/VT) FOR AN OPEN OR SHORT TO GROUND
- Disconnect: Passenger Heated Seat Switch C630
- Measure resistance between:
  - passenger heated seat switch C630-6, circuit 1020 (DG/VT), harness side and heated seat module C681-14, circuit 581 (RD), harness side.
  - passenger heated seat switch C630-6, circuit 1020 (DG/VT), harness side and ground.
- Is resistance less than 5 ohms between heated seat switch and heated seat module and greater than 10,000 ohms between heated seat switch and ground?
1. YES : Go to M3.
2. NO : REPAIR the circuit(s). TEST the system for normal operation.
  DISCONNECT the battery ground cable. DISCONNECT the restraint system diagnostic tool from passenger seat side air bag C316. CONNECT passenger seat side air bag C316. REPOWER the SRS. REFER to GENERAL PROCEDURES article.
M3 CHECK CIRCUIT 581 (RD) FOR A SHORT TO VOLTAGE
- Key in OFF position.
- Connect the battery ground cable. Refer to BATTERY, MOUNTING AND CABLES article.
- Key in ON position.
- Measure voltage between heated seat module C681-14, circuit 581 (RD), harness side and ground.
- Is any voltage present?
1. YES : REPAIR the circuit. TEST the system for normal operation.
  DISCONNECT the battery ground cable. DISCONNECT the restraint system diagnostic tool from passenger seat side air bag C316. CONNECT passenger seat side air bag C316. REPOWER the SRS. REFER to GENERAL PROCEDURES article.
2. NO : INSTALL a new heated seat switch. TEST the system for normal operation.
  DISCONNECT the battery ground cable. DISCONNECT the restraint system diagnostic tool from passenger seat side air bag C316. CONNECT passenger seat side air bag C316. REPOWER the SRS. REFER to GENERAL PROCEDURES article.