P1603

Circuit Description

This diagnostic test checks for the loss of or invalid Sensing/Diagnostic Module (SDM) serial data to the PCM. When such a condition exists for 1 second, DTC P1603 is set.

Conditions for Running the DTC

^ DTC P0322 not set.
^ Engine speed 500 RPM or more for 10 seconds continuously.

Conditions for Setting the DTC

Invalid or no serial data from the SDM to the PCM for 1 second.

Action Taken When the DTC Sets

^ The Malfunction indicator Lamp (MIL) will not illuminate.
^ No message will be displayed.

Conditions for Clearing the DTC

^ A History DTC will clear after forty consecutive warm-up cycles with no failures of any non-emission related diagnostic test.
^ A Last Test Failed (current) DTC will clear when the diagnostic runs and does not fail.
^ Use a scan tool to clear DTCs.
^ Interrupting PCM battery voltage may or may not clear DTCs. This practice is not recommended.