DTC Memory Checking and Erasing

Engine Control Module (ECM) Diagnostic Trouble Code (DTC) Memory, Checking and Erasing

If DTC memory is erased, the Engine Control Module (ECM) unlearns several adaptation values. Depending on vehicle mileage, this can cause driveability problems. In this case, let engine run at idle several minutes or perform a road test until the adaptation procedure has been completed.

Special tools and equipment
- V.A.G 1551 scan tool (or 1552 scan tool) with cable VAG 1551/3

Work sequence

NOTE: All functions which could previously be performed with VAG 1551/1552 can also be performed with the new tester VAS 5051.

- Connect VAG 1551 scan tool ((VAG 1552). Start engine and select "Address word" 01 of engine control module. Engine must be running at idling speed.
(Connecting scan tool and selecting engine control module.) [1][2]Reading and Clearing Diagnostic Trouble Codes

Only when engine does not start:

- Operate the starter for at least 5 seconds. Then do not switch the ignition off.
- Switch on scan tool printer with the print key. The warning lamp in key must light up.

Indicated on display:

Rapid data transfer HELP
Select function XX

- Operate scan tool taking into account the information on the display:
- Press keys 0 and 2 for function "Check DTC memory" and confirm entry with Q key.

The number of malfunctions stored or "No malfunction recognized" will be shown on the display.

X Faults recognized!

If no malfunctions is stored:
- Press -> key.

If one or more malfunctions are stored:
The stored malfunctions will be displayed and printed out one after the other.

After the stored malfunctions have been printed out, the display will show:

Rapid data transfer HELP
Select function XX

- Press keys 0 and 5 for the function "Erase DTC memory" and confirm entry with Q key.

Indicated on display:

Rapid data transfer ->
DTC memory is erased!

NOTE: If the ignition was switched off between "Check DTC memory" and "Erase DTC memory", DTC memory will not be erased. Some DTCs (e.g. for E-gas) can only be erased after switching the ignition off and on again one time.

- Press -> key.

Indicated on display:

Rapid data transfer HELP
Select function XX

- Press keys 0 and 6 for the function "End output" and confirm entry with the Q key.
- Correct faults printed out using DTC table:
Testing and Inspection

- Erase all DTC memories and then road test vehicle.
During the road test the following operating conditions must be fulfilled:
- The coolant temperature must exceed 80°C.
- When the temperature is reached, the operating conditions
Idling
Part throttle
Enrichment
Wide open throttle
Overrun
must be attained several times.
- At wide open throttle the speed must exceed 3500 rpm.

- Generate readiness code again. Monitors, Trips, Drive Cycles and Readiness Codes

NOTE: If DTC memory was erased or the Engine Control Module (ECM) was disconnected from B+, the readiness code must be generated again. Monitors, Trips, Drive Cycles and Readiness Codes