Fleetwood V8-368 6.0L VIN 9 FI (1982)
Ignition Coil: All Technical Service Bulletins
Distributor Coil - Intermittent Code 51 or 52
Bulletin No. T 84-5 2
File In Group
6C
Number
77
Date
Mar. '84
SUBJECT:
INTERMITTENT DFI DIAGNOSTIC CODE 51 AND 52
MODELS AFFECTED: ALL 1982-1984 MODELS EQUIPPED WITH DFI
FIGURE 1 - DISTRIBUTOR CAP/IGNITION COIL
FIGURE 2 - IGNITION COIL EXPLODED
DFI equipped Cadillacs may set code 51 and/or code 52 due to loose or unattached distributor coil grounds. The code may also be accompanied by an
engine stumble or miss, erratic ISC operation, and erratic fuel data panel operation.
The cause is a voltage transient that occurs when the grounds for the high tension side of the ignition coil open and arc.
The ground for the ignition coil secondary windings is provided by a black wire with an eyelet terminal inside the distributor cap cover. The eyelet is
attached to the coil laminations by a coil hold down screw. The ground path goes from the hold down screw through the coil laminations into a stamped
steel ground strap. The ground strap attaches to one of the front coil hold down screws and terminates as the "ground" lug inside the distributor cap. (See
Figures 1 and 2.)
If the eyelet is not tight or if the strap is not securely attached by a hold down screw, the ground may open intermittently causing a spark and code 51 or
52.
