Theory of Operation
WARNING: This page is about a different car, the 2011 RAM Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.
The purpose of this test is to check the internal Powertrain Control Module (PCM) fuel system diagnostic (ASIC) for proper operation by intentionally inducing a failure and looking for the proper PCM response. At key off, the diagnostic overwrites injector on time and falsely cycles the injectors. If the internal PCM detection chip (ASIC) detects the firing and sets an error then the diagnostic passes. This diagnostic initially only runs at key off. If the diagnostic failed at the last key off cycle, then it will also run at the next cranking event. If the driver stalls the engine (manual transmission only) at the same moment that the key is turned off this diagnostic could fail. When the diagnostic fails, the PCM will flash the ETC lamp.