Diagnostic Mode 03 - Read DTC Memory

WARNING: This page is about a different car, the 2009 Audi A8, 2008 Audi A8, 2007 Audi A8, 2006 Audi A8, and 2005 Audi A8. However, it is still accessible from the selected car via links, so may be relevant.

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 → Diagnostic Tester, Connecting .
Start engine and let run at idle.

NOTE:

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 .
SAE P1xxx-DTCs → SAE P1xxx-DTCs .
SAE P2xxx-DTCs → SAE P2xxx-DTCs .
SAE P3xxx-DTCs → SAE P3xxx-DTCs .
SAE U0xxx-DTCs → SAE U0xxx-DTCs .

NOTE:

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 01 - Read Current System Data , 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