For 1990-2009 cars

In order to retrieve diagnostic trouble codes (DTCs) stored by the PBCM, use the following procedure.

1. Turn ON the ignition.
2. Use a flat blade screwdriver in order to short together the two terminals located in the diagnostic port of the PBCM.
3. Observe the diagnostic display on the side of the PBCM and record any DTCs and DTC information.

The PBCM displays DTCs in the order in which they were set. Each DTC is displayed for 3 seconds. The system voltage or system pressure reading which is recorded when DTC 001 or 002 sets, is displayed immediately after the DTC to which it pertains. Voltage and pressure values are only displayed for 1 second. Do not confuse any displayed voltage or pressure values as being DTCs.

A display of "00" indicates that the diagnostic functions of the PBCM are operational and that no DTCs are stored.