1999 Jag Vanden Plas - Restricted Performance message

KB3817

MEMBER
1999 JAGUAR

My 1999 Vanden Plas, 109,000 mi, gives me Restricted Performance message, amber light - a local independent foreign car mechanic said it was the #4 injector and/or coil pack. I had both of the #4 injectors/coil packs replaced and still same problem. It seems to be sporadic and idles really rough. What do you recommend?

1 Reply

DAVE H

MECHANIC
13,383 POSTS

Replace all coils at the same time !

IGNITION SYSTEM
Ignition timing and spark distribution are controlled by ECM or PCM according to sensor inputs. Ignition timing is controlled primarily as a function of engine load and speed. Engine load is sensed by Mass Airflow (MAF) sensor. Engine speed is sensed by a Crankshaft Position (CKP) sensor. The ECM or PCM processes inputs from the sensors and accesses ignition timing from the ignition timing strategy. Individual ignition coils are located above each spark plug. ECM or PCM incorporates the primary circuit for each coil and provides switching for each primary circuit. The correct firing sequence and timing of the ignition coils is determined by ECM or PCM from cylinder synchronization input provided by the Camshaft Position (CMP) sensor.