Two problems related to dash wiring have been reported for the 2003 Toyota Matrix. The most recently reported issues are listed below.
Instrument panel lighting is very poor, obstructing the consumer's ability to see speedometer, gas gauge, and oil pressure.
Consumer believes he has the solution to the Toyota acceleration problem. The consumer stated his daughter drives a 2003 Toyota Matrix and she has been experiencing random dashboard light activity. The consumer stated he has reviewed the wiring diagrams and her dashboard lights are controlled by the integration relay otherwise known as the body control module. It appears that the lack of relay over-voltage suppression on any of the relays in the vehicle has caused damage to the integration relay and there was no way to tell how much damage has been done to the engine control module.