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 alpha-numeric value with 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 sequence
- Connect diagnostic tester. Refer to 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. Refer to SAE P0xxx-DTCs
- SAE P1xxx-DTCs. Refer to SAE P1xxx-DTCs
- SAE P2xxx-DTCs. Refer to SAE P2xxx-DTCs
- SAE P3xxx-DTCs. Refer to SAE P3xxx-DTCs
- SAE U0xxx-DTCs. Refer to SAE U0xxx-DTCs
NOTE:
- The DTC table is sorted by SAE code.
- EPC -relevant malfunctions are also indicated by 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). Refer to Diagnostic mode 2: Check operating conditions
- Erase DTC memory after repairing malfunction. Refer to Diagnostic mode 4: Reset/erase diagnostic data
Display example:
P0444 Evaporative 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