Diagnostic Test

Turn the ignition on.

With the scan tool, record and erase DTCs.

Wait 30 seconds.

With the scan tool, read DTCs.

Does the scan tool display: U0208-LOST COMMUNICATION WITH HEATED SEATS CONTROL MODULE? 

Yes 

1. Go To  2).

No 

1. The condition that caused this code to set is not present at this time. Check for an intermittent condition by inspecting the related wiring harness for chaffed, pierced, pinched, and partially broken wires. Also inspect the related connectors for broken, bent, pushed out, spread, corroded, or contaminated terminals.
2. Perform BODY VERIFICATION TEST - VER 1. Refer to BODY VERIFICATION TEST - VER 1 .

Fig 1: Measuring Voltage Of LIN BUS Circuit

Courtesy of DAIMLERCHRYSLER CORP.

Turn the ignition off.

Disconnect the Heated Seats Module harness connector.

Turn the ignition on.

Measure the voltage of the (D506) LIN BUS circuit.

Is the voltage above 5 volts? 

Yes 

1. Go To  3).

No 

1. Repair the (D506) LIN BUS circuit for an open.
2. Perform BODY VERIFICATION TEST - VER 1. Refer to BODY VERIFICATION TEST - VER 1 .

Fig 2: Measuring Voltage Of Fused Ignition Switch Output (RUN) Circuit

Courtesy of DAIMLERCHRYSLER CORP.

Measure the voltage of the (F937) Fused Ignition Switch Output (RUN) circuit.

Is the voltage above 10 volts? 

Yes 

1. Go To  4).

No 

1. Repair the (F937) Fused Ignition Switch Output (RUN) circuit for an open.
2. Perform BODY VERIFICATION TEST - VER 1. Refer to BODY VERIFICATION TEST - VER 1 .

Fig 3: Measuring Resistance Between Ground & Ground Circuit

Courtesy of DAIMLERCHRYSLER CORP.

Measure the resistance between ground and the (Z908) Ground circuit.

Is the resistance below 10K ohms? 

Yes 

1. Replace the Heated Seats Module in accordance with the service information.
2. Perform BODY VERIFICATION TEST - VER 1. Refer to BODY VERIFICATION TEST - VER 1 .

No 

1. Repair the (Z908) ground circuit for an open.
2. Perform BODY VERIFICATION TEST - VER 1. Refer to BODY VERIFICATION TEST - VER 1 .