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 one DTC entry.

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

Component group:
Pxxxx DTC for drivetrain
Uxxxx DTC for network communication

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

System group:
Px0xx Fuel and air mixture and additional emission regulations
Ux0xx Network, electrical
Px1xx Fuel and air ratios
Ux1xx Network, communication

System group:
Px2xx Fuel and air ratios
Ux2xx Network, communication
Px3xx Ignition system
Ux3xx Network,software
Px4xx Additional exhaust 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 diagnosis and switch ignition off.
- Repair stored malfunctions according to DTC table:
- SAE P0xxx-DTCs. P0030
- SAE P1xxx-DTCs. P1702
- SAE P2xxx-DTCs. P2100
- SAE U0xxx-DTCs. U0001

NOTE:
- The DTC table is sorted by SAE codes.
- "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 by the Engine Control Modules (ECMs), 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. Diagnostic Mode 4: Reset/Erase Diagnostic Data

Display example:
P0183 Fuel Temperature Sensor -G81- Open circuit/short circuit to B+

Explanation:
- P0183 = SAE diagnostic trouble code (malfunction identification number).
- Fuel Temperature Sensor -G81- = faulty circuit or malfunctioning component.
- Open circuit/short circuit to B+ = malfunction type as text.