Diagnostic Mode 03 - Read DTC Memory

Diagnostic Mode 03 makes it possible to read emissions-related faults (confirmed DTCs: faults which have activated the MIL) in the ECM and in the TCM.

When the Diesel Direct Fuel Injection (DFI) Engine Control Module (ECM) -- recognizes an emission related fault it turns on the Malfunction Indicator Lamp (MIL) -- or if a Electronic Throttle Malfunction is recognized, the Diesel Direct Fuel Injection (DFI) Engine Control Module (ECM) -- turns on the Electronic Power Control (EPC) Warning Lamp -- which are both located in the instrument cluster.

The DTC's are sorted by SAE code with the DTC tables consisting of a 5-digit alpha-numeric value.

Depending on scan tool and protocol used, the information displayed in diagnostic mode 03 may be referred to by different names such as Test-ID (TID), Hex-ID, Component-ID (CID), On-Board Diagnostic Monitor Identifier (OBDMID), or contain no name at all and be referenced by only a number.

The following tables provide a breakdown and explanation of the DTC code.

P Codes