PROM - Not Compatable With ALDL Scan Tool
Bulletin 84-6J-1Date May, 1984
Ref. No. 84-108-6J
SUBJECT: 3.8L SFI TURBO PROM CHANGE
MODEL AFFECTED: 1984 T-TYPE RIVIERAS AND REGALS
Early production Rivieras and Regals equipped with turbocharged 3.8L SFI engines may have PROM's that are not compatible with the updated or new ALDL (ALCL) scanner tools when operated in the open mode.
If you are servicing early production vehicles and are unable to obtain useful diagnostic information when using the ALDL (ALCL) scanner tool in the open mode it may be necessary to replace the prom.
VIN break points for open mode diagnostic proms are as follows:
MODEL VIN BREAK POINTS NEW PROM BRDADCAST CODE
Riviera EE428568 16042268 DNP
Regal EH525499 16042261 DNN
Information displayed in the Open mode with this change is as follows:
Oxygen sensor voltage Air Flow Knock retard (in degrees) Block learn fuel Idle air control Engine RPM Park Neutral switch [1][2]Torque converter clutch Power steering (FWD only) EGR (Turbo reads 3rd gear switch when in this position) 4th gear switch Air conditioning (on/off status)
NOTE: Vehicles with VIN's above those listed in this bulletin have the latest open mode diagnostic PROM installed and will not benefit from this change.