Scan Tool Testing and Procedures
Readiness code, reading and generatingNOTE: OBD II legal regulations require a display (readiness code) that shows inspection readiness for the annual exhaust emissions test. The readiness code shows that every component and/or system that affects exhaust emissions, which can lead to the MIL switching on, has been operated at least once with positive results.
NOTE: The readiness code is reset and/or erased every time:
- DTC memory is erased (either with display group O1 function 05 or display group 33 mode 4)
- ECM harness connector is disconnected from ECM -J192- (e.g. connecting test box VAG 1598/19, replacing ECM, etc.)
- Battery is disconnected
Reading readiness code
- Select VAG 1551 "Read Measuring Value Block" function 08.
NOTE: The readiness code can be displayed with the VAG 1551 and/or VAG 1552 scan tools, and also with address word 33, mode 1 (Diagnosis data).
- Display shows display fields 1 through 4.
Read measuring value block 29 -->
1 2 3 4
- Read readiness code in display field 1.
Specified value: 000_00_0
NOTE: The readiness code is set as soon as all display positions is display field 1 are "0."
- Press button.
- Press buttons -0- and -6-to select "End Output" function 06, and press -Q- button to confirm input.
- If the readiness code is not set: Generate readiness code.
Generating readiness code
NOTES:
- In order to generate the readiness code, a "mixed city and highway" drive (short test) has to be taken. A "mixed city and highway" drive is understood as approx. 1-1/2 to 5 minutes at 80-100km/h (50-63mph) with manual transmission in 4th or 5th gear, or automatic transmission selector lever in "0" position, preferably in 4th gear
- If a malfunction is recognized and stored by the engine control module during a "mixed city and highway" trip, and/or the Malfunction Indicator Lamp (MIL) is switched on, the brief test can be interrupted by the technician and the malfunction repaired according to the diagnostic trouble code.
- If the readiness code has to be generated, the DTC memory should be checked (no faults should be stored) and erased (readiness code will be reset) before taking the "mixed city and highway" trip.
Step 1: Preparation
- Start engine and let idle.
- Connect VAG 1551 or VAG 1552 scan tool, switch on printer and select address word 01.
- Check and erase DTC memory.
No malfunctions may be stored. If necessary:
- Repair malfunctions.
- Erase DTC memory.
- Stop engine and start again.
- Test drive and, as a check, check and erase DTC memory again.
- After checking and erasing DTC memory, let engine run at idle again.
Step 2: System readiness checking and creating
- Select VAG 1551 "Read Measuring Value Block" function 08, display group 29.
- Display shows display fields 1 through 4. Specified values:
Read measuring value block 29 -->
1 2 3 4
- Display field 111_01_1 (readiness code)
- Display field 2: 00000000 (trip status display)
- Display field 3: 0
- Display field 4: 0
- Press button.
Indicated on display
Read measuring value block
Input display group number XXX
- Push buttons -0-, -0- and -1-to input display group number 001.
- Press -Q- button to confirm input.
Display shows display fields 1 through 4.
Read measuring value block 1 through 4.
1 2 3 4
- Check display fields 1 and 3:
Note on display field 1: If the displayed value is less than 7O°C, let the vehicle warm up until at least 70°C coolant temperature is attained.
Note on display field 3: If the displayed value is greater than 48 (corresponds to an altitude of approx. 1800m) a diagnosis of the exhaust return can not be conducted due to altitude. Setting the readiness code at this altitude is not possible.
- If specified values are attained - Step 3
Step 3: Conducting workshop diagnosis
- Engine running at idle
- Use VAG 1551 to select "Basic Setting" function 04, display group 045.
Indicated on display (display fields 1 through 4)
System in Basic Setting 45
1 2 3 4
- Diagnosis of the EVAP control system, conducted by the ECM, has ended when display field 1 displays the value 99.
Specified value: 99 (diagnosis has ended)
For vehicles without secondary air system (ECM coding O9xxx):
- Press button and continue with step 4.
For vehicles with secondary air system (ECM coding O6xxx) additional test steps are required:
- Press -C- button.
- Indicated on display
Basic Setting
Input display group number XXX
- Push buttons -0-, -2- and -0- to input display group number 020.
- Press -Q- button to confirm input.
Display shows display fields 1 through 4.
System in Basic Setting 20
1 2 3 4
- The secondary airflow diagnosis is conducted. The diagnosis has ended and is OK if the following value appears in display field 4:
Specified value, display field 4: x1xx1100
- Press -C- button.
- Indicated on display
Basic Setting
Input display group number XXX
- Push buttons -0-, -2- and -1- to input display group number 021.
- Press -Q- button to confirm input.
Display shows display fields 1 through 4.
System in Basic Setting 21
1 2 3 4
- The secondary air injection flow diagnosis is conducted. The diagnosis has ended OK, if the following sample appears in display field 4:
Specified value, display field 4: x1xx1100
- Press button and continue with step 4.
Step 4: Checking of workshop diagnosis
- Select VAG 1551 "Read Measuring Value Block" function 08, display group 29.
- Display shows display fields 1 through 4.
Read Measuring Value Block 29
1 2 3 4
Specified values:
Vehicles without secondary air system (ECM coding 09xxx)
- Display field 1: xxx 00 x (readiness code)
- Display field 2: xxxxx1xx (trip status display)
Vehicles with secondary air system (ECM coding O6xxx)
- Display field 3: 0 (counter, all A6 models)
- Display field 4: 0 (counter, all A6 models)
- If specified values are attained continue with step 5.
Step 5: Road test
NOTE: In order to set the readiness code, a "mixed city and highway" drive is required. The necessary driving conditions for the test drive are listed in the following chart:
Step 6: Checking readiness code
- Select VAG 1551 "Read Measuring Value Block" function 08, display group 29.
- Display shows display fields 1 through 4. Specified values:
Read measuring value block 29
1 2 3 4
- Display field 1: 000_00_0 (readiness code)
- Display field 2: 111 _01(trip status display)
- Display field 3: 0
- Display field 4: 0
- Press button.
- Press buttons -0- and -6-to select "End Output" function 06, and press -Q- button to confirm input.
- If, during regeneration of the readiness code, the trip status display is set to "1" but the corresponding readiness code display is not set to "0" the diagnosis was carried out but not recognized as OK by the ECM.
- In this case, DTC memory should be checked for malfunctions and/or to carry out a selective diagnosis:
- For three way catalytic convertor diagnosis (bank 1 and bank 2), also check display groups 035, 036 and 044.
- For EVAP system leak diagnosis, also check display group 030.
- For heated oxygen sensor diagnosis, also check display groups 032, 033, 034, 041, 042 and 043.
- For oxygen sensor heating diagnosis, also check display group 040
- For Exhaust Gas Recirculation (EGR) throughput diagnosis, also check display group 017.