DeVille V8-4.9L VIN B (1995)
PROM - Programmable Read Only Memory: All Technical Service Bulletins
Service Procedure
The following service procedure is to be performed on certain 1991-1995 model Cadillac vehicles equipped with the 4.9 liter engine (RPO L26), which
can be easily identified by the character "B" in the 8th position of the Vehicle Identification Number.
It is important to note that some 1991 and 1992 model vehicles built before October 24, 1991 may have experienced warranty repairs with a labor
operation code of T6527 or J6364 and received the prom being recalled as a service part. VIN breakpoints for 1992 model vehicles are:
247930 for DeVille
604013 Eldorado
806499 for Seville
Affected 1991 model vehicles and 1992 model vehicle built before these breakpoints should be inspected and repaired if necessary. Dealers must
confirm vehicle eligibility through the Vehicle Information Service System (VISS) and/or their "involved vehicle listing" prior to performing this
inspection. All 1992 model vehicle built after the breakpoints require Mem-Cal replacement using the following procedure.
1.
Determine the PROM ID number by using the appropriate procedure which follows. Note that the use of a Tech 1 diagnostic tool for this purpose
is specifically NOT recommended.
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Turn ignition key to the "RUN" position.
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Simultaneously press and hold the "OFF" and "WARMER" buttons on the Electronic Climate Control (ECC) panel until all segments on the
ECC and Fuel Data Center (FDC) panel are illuminated. Then release the buttons.
A.
All 1991-1993 model C
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Observe the FDC panel. Any Powertrain Control Module (PCM) or Body Control Module (BCM) Diagnostic Trouble Codes which may
be present will be displayed on the FDC panel. Codes will be stored in memory as either history or current codes. Any PCM history
codes will appear first preceded by ..E. Any PCM current codes will then be displayed preceded by E.E. The same sequence will follow
for any BCM codes. BCM codes will follow ..F and F.F readouts for history and current codes respectively. Record all codes on the
repair order for use in diagnosing other possible customer service needs.
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After all Trouble Codes have been displayed .7.0 will display.
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When .7.0 appears on the FDC, press the "LO" button on the ECC panel to access PCM data. E.9.0 will display. Press the "LO" button
again and P.2.5 will display. The PROM ID number will be displayed as a three digit code following P.2.5. Record PROM ID number
on the repair order.
B.
All 1991-1993 model E/K (Except 1993 model ETC, STS, Eldorado Sport Coupe) and 1994-1995 model Ksp except those registered in the
State of California. Note that DeVille Concours is not included.
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Observe the Driver Information Center (DIC). All history or current Powertrain Control Module (PCM) Instrument Panel Cluster (IPC)
Air conditioning programmer (ACP), Supplemental Inflatable Restraint (SIR) and Traction Control System (TCS) codes which are
present will be displayed in that order followed by PCM?. Record all codes on the repair order for use in diagnosing other possible
customer service needs. After PCM? is displayed, press "HI" to access PCM DATA?. Press "HI" again to enter PCM parameters and
PDO1 will display. Press "LO" and PD99 will display preceded by the 3 or 4 digit PROM ID number. Record PROM ID number on the
repair order.
