Test Description

The numbers below refer to the step numbers in the diagnostic procedure.

1. 2  - Lack of communication may be due to a malfunction of the serial data circuit, control module, or scan tool. This step will determine the particular condition.
2. 5  - This step stores the PCM DTC information into the scan tool memory. Review the captured information at the end of the diagnostic procedure to catch the next DTC in the event there are multiple DTCs stored. Use this information to determine how frequently and how recently the DTC set. This information and other operating conditions when the DTC set may help diagnose an intermittent condition. Capturing stored information preserves data the PCM loses when the following occurs:
   • When instructed to clear DTCs.
   • PCM connectors are disconnected.
   • PCM is replaced during a diagnostic procedure or a repair procedure.
3. 6  - A DTC P1600 that is stored must be diagnosed first. If multiple powertrain DTCs are stored, diagnose in the following order of priority:
   • Component Level DTCs  - Sensors, solenoids, relays etc. Multiple DTCs within this category should be diagnosed in numerical order starting with the lowest numbered DTC, unless otherwise directed.
   • System Level DTCs  - Misfire, fuel trim, catalyst etc.
4. 8  - This step is for vehicles that are located in areas that have an Inspection/Maintenance or emission testing program. The testing facility found one or more I/M system statuses not set.