Diagnostic Test

CHECK FOR AN ACTIVE DTC
1. Turn the ignition on.
2. With the scan tool, record and erase Diagnostic Trouble Codes (DTCs).
3. Operate the Heated Seat Switch in both positions several times.
4. With the scan tool, read DTCs.
  Does the scan tool display this DTC as active?
  
  Yes
  - Go To 2.
  No
  - Test complete, the condition or conditions that originally set this DTC are not present at this time. Using the wiring diagrams as a guide, check all related splices and connectors for signs of water intrusion, corrosion, pushed out or bent terminals, and correct pin tension. Attempt to reproduce condition by adjusting the seat.
  - Perform the BODY VERIFICATION TEST. Refer to STANDARD PROCEDURE - BODY VERIFICATION TEST .
CHECK FOR OPEN SEAT HEATER ELEMENTS

Fig 1: Checking For Open Seat Heater Elements
Courtesy of CHRYSLER LLC
1. Turn the ignition off.
2. Disconnect the Left Seat Cushion Heater harness connector.
  NOTE:
  Check connectors. Clean and repair as necessary.
3. Measure the total resistance of the Cushion and Seat Back Heater Elements between the (P187) Left Seat Heater B(+) Driver circuit and the (Z905) Ground circuit at the Left Seat Cushion Heater connector (component side).
  Is the total resistance 2.5 to 3.5 Ohms (+ or - 0.5 of an Ohm)?
  
  Yes
  - Go To 3.
  No
  - Go To 5.
CHECK (Z903) GROUND CIRCUIT FOR AN OPEN

Fig 2: Checking Ground Circuit For An Open
Courtesy of CHRYSLER LLC
1. Using a 12-volt test light connected to 12-volts, check the (Z903) Ground circuit at the Left Seat Cushion Heater harness connector (harness side).
  NOTE:
  The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery.
  
  Does the test light illuminate brightly?
  
  Yes
  - Go To 4.
  No
  - Repair the (Z903) Ground circuit for an open.
  - Perform the BODY VERIFICATION TEST. Refer to STANDARD PROCEDURE - BODY VERIFICATION TEST .
CHECK (P187) LEFT SEAT HEATER B(+) DRIVER CIRCUIT FOR AN OPEN IN BODY HARNESS

Fig 3: Measuring Resistance Of Left Seat Heater B (+) Driver Circuit
Courtesy of CHRYSLER LLC
1. Disconnect the HSM harness connector.
  NOTE:
  Check connectors. Clean and repair as necessary.
2. Measure the resistance of the (P187) Left Seat Heater B(+) Driver circuit between the HSM harness connector and the Left Seat Cushion Heater harness connector (harness side).
  Is the resistance below 5.0 Ohms?
  
  Yes
  - Replace the Heated Seat Module (HSM) in accordance with the Service Information.
  - Perform the BODY VERIFICATION TEST. Refer to STANDARD PROCEDURE - BODY VERIFICATION TEST .
  No
  - Repair the (P187) Left Seat Heater B(+) Driver circuit for an open.
  - Perform the BODY VERIFICATION TEST. Refer to STANDARD PROCEDURE - BODY VERIFICATION TEST .
CHECK LEFT SEAT BACK HEATER ELEMENT FOR AN OPEN

Fig 4: Measuring Resistance Of Left Seat Back Heater Element
Courtesy of CHRYSLER LLC
1. Disconnect the Left Seat Back Heater harness connector.
  NOTE:
  Check connectors. Clean and repair as necessary.
2. Measure the resistance of the Left Seat Back Heater Element between the (P187) Left Seat Heater B(+) Driver and the (Z905) Ground circuit at the Left Seat Back Heater connector (component side).
  Is the resistance above 6.0 Ohms?
  
  Yes
  - Replace the Seat Back Heater Element in accordance with the Service Information.
  - Perform the BODY VERIFICATION TEST. Refer to STANDARD PROCEDURE - BODY VERIFICATION TEST .
  No
  - Replace the Seat Cushion Heater Element in accordance with the Service Information.
  - Perform the BODY VERIFICATION TEST. Refer to STANDARD PROCEDURE - BODY VERIFICATION TEST .