One problem related to anti-theft controller has been reported for the 2003 Mitsubishi Diamante. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2003 Mitsubishi Diamante based on all problems reported for the 2003 Diamante.
Car doors are locking by themselves, the alarm for keys being left in the ignition no longer sounds, the automatic unlock when keys left in the ignition no longer works, and the headlights do not turn off when the car is turned off and door opened. Have been stranded several times due to keys locked in the car, and a dead battery due to headlights being left on.
| Ignition problems | |
| Anti-theft Controller problems |