Reading Diagnostic Trouble Codes

Diagnostic Modes 01 - 09

Diagnostic Mode 03 - Read DTC Memory

The information provided in Modes 01 through 09 displays the various levels of emission related data that may be monitored, as well as the ability to retrieve and read stored DTC trouble codes, erase stored DTC trouble codes, generate readiness codes, and select the various PIDs and Test-IDs used within the modes to monitor the engine, and emission related component parameters.

• Depending on scan tool and protocol used, the information in diagnostic mode 01 may be referred to by different names such as Test-ID (TID), Hex-ID, Component-ID (CID), or On-Board Diagnostic Monitor Identifier (OBDMID).

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.

- Connect diagnostic tester.

- Start engine and let run at idle.

• Only when engine does not start:

• Operate starter for approx. 6 seconds. Do not switch off ignition afterwards.

- Under address word 33, select "Diagnostic mode 3: Read DTC memory". "0 malfunctions recognized" is displayed.

- End diagnosis and switch ignition off.

- Repair stored malfunctions according to DTC table:

• SAE P0xxx-DTCs => [ SAE P0xxx-DTCs ] Testing and Inspection,

• SAE P1xxx-DTCs => [ SAE P1xxx-DTCs ] Testing and Inspection,

• SAE P2xxx-DTCs => [ SAE P2xxx-DTCs ] Testing and Inspection,

• SAE P3xxx-DTCs => [ SAE P3xxx-DTCs ] Testing and Inspection,

• SAE U0xxx-DTCs => [ SAE U0xxx-DTCs ] Testing and Inspection.

• The DTC table is sorted by SAE code.

• "EPC"-relevant malfunctions are also indicated by the "Electronic Power Control (EPC) Warning Lamp" in the instrument cluster.

• In addition, "emission"-relevant malfunctions are indicated in the instrument cluster via the Malfunction Indicator Lamp (MIL).

• In Diagnostic mode 2, it can be determined at which operating condition a malfunction was detected and stored => [ Diagnostic Mode 02 - Read Operating Conditions ] , Diagnostic mode 2: Check operating conditions.

• Erase DTC memory after repairing malfunction => [ Diagnostic Mode 04 - Erase DTC Memory ] , Diagnostic mode 4: Reset/erase diagnostic data.

Display example:

P0444 Evaporative Emission (EVAP) Canister Purge Regulator Valve (N80) circuit open

Explanation:

• P0444 = SAE diagnostic trouble code (malfunction identification number).

• Evaporative Emission (EVAP) Canister Purge Regulator Valve (N80) = malfunctioning wiring path or malfunctioning component.

• Open circuit = Malfunction type as text