Seat Temperature Element: Testing and Inspection
Rear Seat Heating Does Not Work
Fault symptoms
Rear seat heating does not work for one or both pads.
Conditions
A break in the circuit from the relay to the heating pad or a break in the circuit to pin 9 of the control module.
Diagnostic help
The control module output can be activated and the input from the switch can be read with the diagnostic tool.
If the indicator lamp lights on activation of the control module output, the fault probably lies between fuse B and pin 9 on TWICE.
If the indicator lamp does not light on activation of the control module output, the fault probably lies in the circuit from relay (511) to the heating pad (64RL/RR).
Check the wiring
Move the wiring harness at several locations and in different directions to detect intermittent breaks and short-circuits. Observe the multimeter, test lamp or diagnostic tool during the check.