Diagnostic Mode 3: Check DTC Memory

Diagnostic mode 3: Check DTC Memory

Function
This diagnostic mode indicates all stored DTCs of components and systems which are emission relevant.

Malfunction Indicator Lamp (MIL) in instrument cluster lights up for a DTC entry.

SAE Diagnostic Trouble Codes (DTCs)
The DTC always consists of a 5-digit alphanumeric value with the following meaning:

Component group:
- Pxxxx = DTC for drivetrain.
- Uxxxx = DTC for network communication.

Norm-Code:
- P0xxx and U0xxx = DTCs defined by SAE with specified malfunction texts.
- P1xxx and U1xxx = additional emission relevant DTCs provided by manufacturer.
- P2xxx = DTCs defined by SAE with specified malfunction texts.
- U2xxx = additional emission relevant DTCs provided by manufacturer.
- P3xxx and U3xxx = additional emission relevant DTCs provided by manufacturer.

System group:

- Px0xx = Fuel-air mixture and additional emission regulations
- Ux0xx = Network, electrical
- Px1xx = Fuel and air ratio.
- Ux1xx = Network, communication.
- Px2xx = Fuel and air ratio.
- Ux2xx = Network, communication.
- Px3xx = Ignition system.
- Ux3xx = Network, Software.
- Px4xx = additional emission regulation.
- Ux4xx = Network, data.
- Px5xx = Speed and idle control.
- Px6xx = Control module and output signals.
- Px7xx = Transmission.
- Px8xx = Transmission.
- Px9xx = Control modules, input and output signals.

Work procedure
- Connect diagnostic tester. Diagnostic Tester, Connecting
- Start engine and let run at idle.


NOTE: Only if engine does not start:
- Operate starter for approx. 6 seconds. Do not switch ignition off afterward.


- Under address word 33, select "Diagnostic mode 3: Check DTC memory."
The number of stored malfunctions or "0 malfunctions detected" is displayed.

- End diagnostic and switch ignition off.
- Repair stored malfunctions according to DTC table:
SAE P0xxx-DTCs P0010
SAE P1xxx-DTCs P1127
SAE P2xxx-DTCs P2090
SAE P3xxx-DTCs P3081
SAE U0xxx-DTCs U0001


NOTE:
- The DTC table is sorted by SAE code.
- "E-Gas"-relevant malfunctions are also indicated by the warning lamp for Electronic Power Control ("EPC warning lamp") in the instrument cluster.
- "Emission"-relevant malfunctions are additionally 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 by the Engine Control Module (ECM), Diagnostic mode 2: Checking operating conditions. Diagnostic Mode 2: Check Operating Conditions
- Erase DTC memory after repairing malfunction, Diagnostic mode 4: Reset/erase diagnostic data.


Display example:
P0444Evaporative Emission System Purge Control Valve Circuit Open

Explanation:
- P0444 = SAE diagnostic trouble code (malfunction identification number).
- Evaporative Emission System Purge Control Valve = malfunctioning wiring path or malfunctioning component.
- Circuit Open = Malfunction type as text.