Test Notes

*** THIS ARTICLE REFLECTS CHANGES MADE BY TSB # 9326B26, December 1993


NOTE: Diagnostic Trouble Code (DTC) P1000 indicates that not all of the On-Board Diagnostic II (OBD II) monitors have completed. In some states, this code must be cleared to pass an inspection/maintenance test. The customer should be informed that the law specifies additional city and highway driving must be done to complete the check of the On-Board Diagnostic system. This additional driving must occur before the vehicle is tested at the inspection/maintenance station. The amount of driving required varies with individual driving patterns. To complete this requirement in the shortest amount of time, refer to the Owner's Manual.

DTC P1000 is set by the Powertrain Control Module (PCM) with any of the following conditions:

- The vehicle is new from the factory and has not yet been through a complete OBD II Drive Cycle.

- The battery or PCM has been disconnected.

- An OBD II monitor failure had occurred before completion of an OBD II Drive Cycle.

- The PCM DTCs have been erased with a Scan Tool as part of the normal repair process.


A DTC P1000 may not be removed from the PCM memory because:

- A thermostat is stuck open and there is no DTC.

- There is an open VSS circuit and no DTC.

The only way a DTC P1000 can be removed from memory is when all the OBD II monitors have successfully completed during normal vehicle operation.


REMEMBER: It is not necessary to remove the P1000 from the PCM by driving the vehicle unless it is requested by the customer to pass an inspection/maintenance test.


Inform the customer of the need for additional driving when required to pass an inspection/maintenance test.