One problem related to ignition has been reported for the 2003 Mercury Grand Marquis. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2003 Mercury Grand Marquis based on all problems reported for the 2003 Grand Marquis.
Vehicle stalled at any speed, stalled 25 times. Vehicle has been examined by dealer 4 times. Dealer could not duplicate the problem. Vehicle had been at dealer a total of 36 days. Primary computer was reset, then replaced by dealer. This did not remedy the problem.