2009 Audi S4 AutomaticFACTORY OEM SERVICE PROCEDURE

Mode 03: Interrogating fault memory

Description 

When the 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 Engine Control Module (ECM) turns on the Electronic Power Control (EPC) Warning Lamp which are both located in the instrument cluster.

Diagnostic Mode 03 is used to retrieve and view any DTC which may be stored in the Engine Control Module (ECM).

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

NOTE:
  • Depending on scan tool and protocol used, diagnostic mode 03 and the information provided may be referred to by a different name.

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

P-Codes 

Component group
P x x x x DTC for the drivetrain
Norm-Code
P 0 x x x Trouble codes defined by SAE with specified malfunction texts
P 1 x x x Additional emission relevant DTCs provided by the manufacturer
P 2 x x x DTCs defined by SAE with specified texts, from MY 2000
P 3 x x x Additional emission relevant DTCs provided by the manufacturer from MY 2000
Component group
Repair group
P x 0 x x Fuel and air mixture and additional emission regulations
P x 1 x x Fuel and air ratios
P x 2 x x Fuel and air ratios
P x 3 x x Ignition system
P x 4 x x Additional exhaust system
P x 5 x x Speed and idle control
P x 6 x x Control module and output signals
P x 7 x x Transmission
P x 8 x x Transmission
P x 9 x x Control modules, input and output signals

U-Codes 

Component group
U x x x x DTC for network (CAN bus)
Norm-Code
U 0 x x x Trouble codes defined by SAE with specified malfunction texts
Factory Service Tools

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.