Reader, carmaker differ on how seat wire broke

Q: My wife is 4-foot-11 and drives a 2009 Mitsubishi Lancer (purchased new) which now has 40,000 kilometres on it. When she gets into the car, she moves the seat up to the closest position. When she exits the car, she moves the seat back. This past December, the SRS (supplemental restraint system) warning light was coming on intermittently. The dealer asked if the car had been in an accident, which it had not. After further testing at another dealership, and much back-andforth delay, they advised that the SRS wire had been cleanly cut under the driver’s sear, potentially by someone trying to steal the airbags. They charged us $50 for the test and stated that it was not covered by warranty. It appears to me that there’s not enough slack in the SRS wiring to allow for the seat to move through its full adjustment range. I suspect the wire hadn’t been cut but instead broke because of this. A: Lara Brown, manager of public relations for Mitsubishi Motor Sales of Canada (MMSCAN), replies: The dealer inspection of the vehicle wiring harness directly under the driver’s seat of the subject vehicle found that the SRS wire was severed. The dealer felt there was no evidence of a warrantable defect, as the wire loom had adequate slack when in full forward and aft positions. In addition, only the SRS harness in the loom was broken at its connection location – whereas all other wires sharing the same loom were intact and in good condition. Photos were taken and forwarded to a field representative who forwarded them to MMSCAN Technical help desk for assistance/technical opinion. Our Technical Help desk concurred with the dealer’s decision. Note that all 2009 Lancer GTS models carry the exact same standardized wire loom(s), connectors, flexibility level, bracket locations, etc. If a widespread manufacturer’s defect were present, as suggested by the complainant, then such incidents would be frequently investigated by MMSCAN — which is not the case.

The probable cause in this instance appears to be that a possible obstruction under the seat at some point may have caused the wire to be damaged/pinched when the seat was moved, causing a weakening of the SRS wire at the connection. Continual movement of the seat weakened the wire, to the point where it resulted in an open circuit.

Since the broken wire is an integral part of the SRS system, wire repairs are not an option as repairs to wires can introduce a change in resistance of the SRS circuit. Therefore, the only option is to replace the entire wire loom of the seat. The loom is integral to the seat (not available separately), therefore the entire seat/loom needs replacement. Unfortunately, the replacement of a seat is costly.

This customer was notified of our findings via email, where it was reiterated that the repair was not warrantable. Eric Lai adds: Our reader disagrees with Mitusbishi Canada’s findings and points to the discrepancy between the dealer determining it was cut and the reply above suggesting it broke from wear, an obstruction, or repeated movement.

In any case, our reader might wish to check with an auto electric expert for their opinion on the matter before deciding whether or not to take further action. Got a beef? Send it to Eric Lai at wheels@thestar.ca. Include year, make, model and kilometres of autos cited, plus your name, address and telephone number. Personal replies cannot be handled due to volume.