Cutlass V6-191 3.1L VIN M SFI (1998)
Powertrain Control Module: Service and Repair
Password Learn Procedure
In order for a theft deterrent vehicle to run, a password is communicated between the Body Function Control (BFC) and the PCM. If a PCM is replaced,
the new PCM needs to learn the correct password of the vehicle. When the new PCM is installed, the Electrically Erasable Programable Read Only
Memory (EEPROM) calibration is flashed into the new PCM and the vehicle will learn the new password upon the initial ignition ON cycle. If the Body
Function Control (BFC) is replaced, the PCM needs to learn the new password from the Body Function Control (BFC). The password learn procedure is
as follows:
1. Attempt to the start vehicle. The vehicle will stall.
2. Leave the ignition ON until the Theft System telltale turns off (approx.10 minutes).
3. Turn the ignition switch OFF.
4. Attempt to the start vehicle. The vehicle will start on the this attempt. The password is now learned.
Attempting to start the vehicle by bypassing the Passlock II system or substituting parts without performing the password learn procedure may set a DTC
P1631 and P1632.
If no password is received a DTC P1626 ,P1632, and U1064 may be set.
Refer to the applicable DTC table if set.
