On Board Diagnostic (OBD) - 2.8l v6 Aha Audi A6 C5

Function

The Multiport Fuel Injection (MFI) system is equipped with an Engine Control Module (ECM) -J220- with On Board Diagnostic (OBD) capability.

When malfunctions occur in sensors or components monitored by OBD, Diagnostic Trouble Codes (DTC) are stored in DTC memory.

Stored DTCs are identified using the VAG1551 Scan Tool (ST). See CHECK DTC MEMORY (SCAN TOOL FUNCTION 02) .

After the necessary repairs are completed, DTC memory must be erased. See ERASE DTC MEMORY (SCAN TOOL FUNCTION 05) .

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 Malfunction Indicator Lamp (MIL) being switched on, has been operated at least once with positive results.

The readiness code is reset and/or erased and must be regenerated every time DTC memory is erased, the power supply to the ECM -J220- is interrupted (example: when connecting test box VAG1598/22), or the battery has been disconnected. See READINESS CODE, GENERATING .

Malfunction Indicator Lamp (MIL) function, checking

If a malfunction is recognized by the Engine Control Module (ECM) or the Transmission Control Module (TCM), this is indicated by the MIL coming on.

Identifying Malfunction Indicator Lamp (MIL). Scheme 1

Malfunction Indicator Lamp (MIL)

Note. When a recognized malfunction switches on the MIL, it will either blink or light continuously. In either case, DTC memory must be checked. See CHECK DTC MEMORY (SCAN TOOL FUNCTION 02) . If the MIL starts to blink, there is a malfunction that can lead to damage of the Three Way Catalytic Converter (TWC). In this case, driving should only continue using reduced power. The malfunction must be rectified as quickly as possible. If the MIL lights continuously, there is a malfunction that affects exhaust emissions. In this case, DTC memory must be checked, and the malfunction must be rectified as quickly as possible. Some malfunctions may occur without causing the MIL to come on. When driveability or performance problems are reported, and there is no indication from the MIL, the operation of the MIL must be checked. In addition, DTC memory must be checked, as there may be malfunctions stored that do not switch the MIL on immediately.

Scheme 2

1. Switch ignition on. MIL must light up.
2. If MIL does not light when ignition is switched on, check wiring to MIL as follows: (Scheme 2): MIL Does Not Light When Ignition Is Switched On Trouble Shooting

If MIL lights up when ignition is switched on, continue checking as follows

1. Start engine and let run at idle. MIL must go out after a few seconds.

If MIL does not go out

1. Check Diagnostic Trouble Code (DTC) memory. See «CHECK DTC MEMORY (SCAN TOOL FUNCTION 02)»(/audi/a6/c5-1997-2001/remont/testing-diagnostics/#on-board-diagnostic-obd-28l-v6-aha) .

If there are no malfunctions stored in DTC memory

MIL Does Not Go Out Troubleshooting. Scheme 3

Memory

1. Temporary memory and permanent memory. If the engine control module is disconnected from the Battery Positive Voltage (B+) supply, the readiness code and learning values will be erased. Any malfunctions stored in DTC memory are not erased.

Data output

1. Rapid data transfer
2. Additional malfunction indication by Malfunction Indicator Lamp (MIL) lighting up

ECM identification

1. See «VAG1551/VAG1552 SCAN TOOL (ST), CONNECTING AND SELECTING "ENGINE ELECTRONICS" ADDRESS WORD 01»(/audi/a6/c5-1997-2001/remont/testing-diagnostics/#on-board-diagnostic-obd-28l-v6-aha__vag1551vag1552-scan-tool-st-connecting-and) ; VAG1551 Scan Tool (ST), connecting and selecting "Engine Electronics" address word 01.

ECM functions

1. The Motronic ECM -J220- performs different OBD functions, carried out with the ignition switched on or with the engine running. Following are the conditions required to perform each of the specific functions.

Address words

ECM ADDRESS WORDS

Functions under "Engine Electronics" address word 01

FUNCTIONS UNDER "ENGINE ELECTRONICS" ADDRESS WORD 01

Modes under address word 33

MODES UNDER ADDRESS WORD 33

1. Under Address word 33, Modes 1-7 can be addressed.
2. Under Mode 1, individual measuring values can be displayed. Mode 1 is not recommended for use in an Audi Service department, because these values can be displayed much more precisely using address word 01 and "Basic Setting" function 04 or "Read Measuring Value Block" function 08.
3. Mode 2 shows the operating conditions under which the stored malfunctions were recognized.
4. With Mode 3, DTC memory is checked -with Mode 4, DTC memory is erased.
5. Mode 5 shows the statistical value of the oxygen sensors as mandated by law. As these values have no direct bearing on oxygen sensor diagnosis, Mode 5 is of no particular value in an Audi Service department.
6. Under Mode 6, values can be checked for components and systems that are not continuously monitored.
7. With Mode 7 all malfunctions can be checked, even if they have not switched on the Malfunction Indicator Lamp (MIL) (if the MIL has not been switched on, there is no malfunction recognized under Mode 3) .

VAG1551/VAG1552 Scan Tool (ST), connecting and selecting "Engine Electronics" address word 01

Required special tools and test equipment

VAG1551 Scan Tool (ST) with VAG1551/3 adapter cable

Note. VAG1552 can also be used, but there is no print -out capability.

Requirements

1. Fuses for engine electronics OK
2. Battery Positive Voltage (B+) OK (at least 11 volts)
3. Engine and transmission GND connections OK
4. Fuel pump relay OK

Scheme 4

1. Locate Data Link Connector (DLC), under driver's knee bar to left side of steering wheel.
2. Connect VAG1551 Scan Tool (ST) with VAG1551/3 adapter cable to DLC. (Scheme 4): Connecting VAG 1551 Scan Tool To DLC
3. Switch ignition on, or start engine, depending on function to be selected (see «ON BOARD DIAGNOSTIC (OBD) TECHNICAL DATA»(/audi/a6/c5-1997-2001/remont/testing-diagnostics/#on-board-diagnostic-obd-28l-v6-aha) ).

Note. If scan tool displays do not appear as indicated: Refer to scan tool operating instructions If "Error in communication link" is displayed, disconnect adapter cable at scan tool, reconnect, and repeat procedure.

Scheme 5

1. Operate scan tool and advance through program sequence by following display: Press button -1- to select "Rapid data transfer" operating mode 01. Press buttons -0- and -1- to insert "Engine Electronics" address word 01, and press -Q- button to confirm input. (Scheme 5): VAG 1551 Scan Tool Display - ECM Identification And Coding

Indicated on display (ECM identification and coding, example)

ECM IDENTIFICATION AND CODING, EXAMPLE

Note. If the ECM version that corresponds to the vehicle is not displayed, replace ECM. See ENGINE CONTROL MODULE (ECM) (WITHOUT METAL ANTI-THEFT HOUSING), REMOVING AND INSTALLING . Incorrect ECM coding leads to: Performance problems (e.g. jerky shifting, abrupt load changes, etc.) Increased fuel consumption Elevated exhaust gas values Reduction in transmission service life Storage of non-existent malfunctions in DTC memory Necessary functions not being carried out (oxygen sensor control, actuation of EVAP canister system, etc.)

Scheme 6

1. Press --> button to advance through program sequence. (Scheme 6): VAG Scan Tool Display - Rapid Data Transfer

Indicated on display

1. Continue as specified in procedures for specific OBD functions.

Code Control Module (scan tool function 07)

If vehicle -specific code is not displayed, or if the ECM has been replaced, the ECM must be coded as follows.

VAG1551 Scan Tool (ST) with VAG1551/3 adapter cable

Coding procedure

1. Connect VAG1551/VAG1552 Scan Tool (ST) and press buttons -0- and -1- to insert "Engine Electronics" address word 01 (ignition switched on). See «VAG1551/VAG1552 SCAN TOOL (ST), CONNECTING AND SELECTING "ENGINE ELECTRONICS" ADDRESS WORD 01»(/audi/a6/c5-1997-2001/remont/testing-diagnostics/#on-board-diagnostic-obd-28l-v6-aha__vag1551vag1552-scan-tool-st-connecting-and) .

Indicated on display

VAG Scan Tool Display - Code Control Module, Scan Tool Function 07 (1 Of 5). Scheme 7

1. Press buttons -0- and -7- to select "Code Control Module" function 07, and press -Q- button to confirm input.

Indicated on display

VAG Scan Tool Display - Code Control Module, Scan Tool Function 07 (2 Of 5). Scheme 8

1. Input applicable code number for vehicle, and press -Q- button to confirm input. See «ECM CODING VARIATIONS»(/audi/a6/c5-1997-2001/remont/testing-diagnostics/#on-board-diagnostic-obd-28l-v6-aha__ecm-coding-variations) .

If indicated on display

VAG Scan Tool Display - Code Control Module, Scan Tool Function 07 (3 Of 5). Scheme 9

Incorrect code number has been entered.

Indicated on display (ECM identification and coding, e.g. 06052)

VAG Scan Tool Display - Code Control Module, Scan Tool Function 07 (4 Of 5). Scheme 10

1. Press --> button to advance through program sequence.

Indicated on display

VAG Scan Tool Display - Code Control Module, Scan Tool Function 07 (5 Of 5). Scheme 11

1. Press buttons -0- and -6- to select "End Output" function 06, and press -Q- button to confirm input.

Note. The Motronic ECM -J220- only uses the code that has been entered after the ignition has been switched off once. Incorrect coding leads to

1. Performance problems (e.g. jerky shifting, abrupt load changes, etc.)
2. Increased fuel consumption
3. Elevated exhaust gas values
4. Storage of non-existent malfunctions in DTC memory
5. Reduction in transmission service life

ECM coding variations

ECM CODING VARIATIONS

ECM CODE NUMBER STRUCTURE (EXAMPLE)

Note. Vehicles with traction control (ASR) can be recognized by the ASR control light in the instrument cluster or by ABS/ASR On Board Diagnostic (OBD). Repair Manual, Brake System On Board Diagnostic (OBD), Repair Group 01 The leak detection pump is located in the left rear wheel well behind the wheel housing liner.

VAG1551 Scan Tool (ST) with VAG1551/3 adapter cable

Checking

1. Connect VAG1551/VAG1552 Scan Tool (ST) and press buttons -0- and -1- to insert "Engine Electronics" address word 01 (engine running at idle). See «VAG1551/VAG1552 SCAN TOOL (ST), CONNECTING AND SELECTING "ENGINE ELECTRONICS" ADDRESS WORD 01»(/audi/a6/c5-1997-2001/remont/testing-diagnostics/#on-board-diagnostic-obd-28l-v6-aha__vag1551vag1552-scan-tool-st-connecting-and) .

Note. If engine does not start: Operate starter to crank engine for approx. 6 seconds, then do not switch ignition off.

1. Press PRINT button to switch scan tool printer on (indicator light in button lights up).

Indicated on display

VAG Scan Tool Display - Check DTC Memory, Scan Tool Function 02 (1 Of 3). Scheme 12

1. Press buttons -0- and -2- to select "Check DTC Memory" function 02, and press -Q- button to confirm input.

Indicated on display (number of stored malfunctions, or "No DTC recognized")

VAG Scan Tool Display - Check DTC Memory, Scan Tool Function 02 (2 Of 3). Scheme 13

Note. If scan tool displays do not appear as indicated: Scan tool operating instructions

If one or more malfunctions are stored

Stored malfunctions are displayed one after another, and are printed out along with applicable DTCs.

Indicated on display (after all stored malfunctions)

VAG Scan Tool Display - Check DTC Memory, Scan Tool Function 02 (3 Of 3). Scheme 14

If no DTCs are recognized

1. Press button to advance through program sequence.
2. Press buttons -0- and -6- to select "End Output" function 06, and press -Q- button to confirm input.
3. Repair malfunctions according to «DIAGNOSTIC TROUBLE CODE (DTC) TABLE»(/audi/a6/c5-1997-2001/remont/testing-diagnostics/#on-board-diagnostic-obd-28l-v6-aha__diagnostic-trouble-code-dtc-table) .
4. Erase DTC memory. See «ERASE DTC MEMORY (SCAN TOOL FUNCTION 05)»(/audi/a6/c5-1997-2001/remont/testing-diagnostics/#on-board-diagnostic-obd-28l-v6-aha) .

Diagnostic Trouble Code (DTC) table

Note. The DTC table is organized according to SAE and VAG diagnostic trouble codes. The column labeled "MIL" specifies the MIL switching condition associated with that DTC. DTCs that do not switch on the MIL after the malfunction is recognized by the ECM are identified by the MIL switching condition "Off". DTCs that switch on the MIL immediately after the malfunction is recognized by the ECM are identified by the MIL switching condition "Immed.". DTCs that are recognized by the ECM and switch on the MIL after two consecutive driving cycles (Dcy) are identified by the MIL switching condition "2 Dcy". Always correct malfunctions that are designated "immed." as soon as possible, followed by those malfunctions that are designated "2 Dcy". When all repairs have been completed, go to ERASE DTC MEMORY (SCAN TOOL FUNCTION 05) . Then generate new readiness code ( READINESS CODE, GENERATING ). DTCs that are recognized as a result of intermittent malfunctions, or DTCs that are not erased after repairs are classified as sporadic malfunctions. These are identified by the designation "SP" appearing in the display. A sporadic malfunction will be erased if it no longer occurs after 50 driving cycles during which the engine reaches operating temperature.

SAE AND VAG DIAGNOSTIC TROUBLE CODES (P0102 TO P1914)

VAG1551 Scan Tool (ST) with VAG1551/3 adapter cable

Test condition

1. Malfunction(s) repaired

Note. If DTC memory has been erased, generate new readiness code. See READINESS CODE, GENERATING .

Erasing

1. Connect VAG1551/VAG1552 Scan Tool (ST) and press buttons -0- and -1- to insert "Engine Electronics" address word 01 (engine running at idle). See «VAG1551/VAG1552 SCAN TOOL (ST), CONNECTING AND SELECTING "ENGINE ELECTRONICS" ADDRESS WORD 01»(/audi/a6/c5-1997-2001/remont/testing-diagnostics/#on-board-diagnostic-obd-28l-v6-aha__vag1551vag1552-scan-tool-st-connecting-and) .

Indicated on display

VAG Scan Tool Display - Erase DTC Memory, Scan Tool Function 05 (1 Of 4). Scheme 15

1. Press buttons -0- and -2- to select "Check DTC Memory" function 02, and press -Q- button to confirm input.
2. Press --> button to advance through program sequence until all stored malfunctions have been displayed.

Indicated on display

VAG Scan Tool Display - Erase DTC Memory, Scan Tool Function 05 (2 Of 4). Scheme 16

1. Press buttons -0- and -5- to select "Erase DTC Memory" function 05, and press -Q- button to confirm input.

Indicated on display

VAG Scan Tool Displa - Erase DTC Memory, Scan Tool Function 05 (3 Of 4). Scheme 17

1. Press --> button to advance through program sequence.

Indicated on display

VAG Scan Tool Display - Erase DTC Memory, Scan Tool Function 05 (4 Of 4). Scheme 18

1. Press buttons -0- and -6- to select "End Output" function 06, and press -Q- button to confirm input.
2. Road test vehicle. Safety precautions for road testing vehicle, see «SAFETY PRECAUTIONS»(ref-216409-S10796765012006012100000) .
3. Initiate "Automatic Test Sequence" by pressing -0- button twice to insert address word 00 and press -Q- button to confirm input.
4. Check readiness code. See «READINESS CODE»(/audi/a6/c5-1997-2001/remont/testing-diagnostics/#on-board-diagnostic-obd-28l-v6-aha) . If DTC memory has been erased, or ECM has been disconnected, generate readiness code «READINESS CODE, GENERATING»(/audi/a6/c5-1997-2001/remont/testing-diagnostics/#on-board-diagnostic-obd-28l-v6-aha) .

Output Diagnostic Test Mode (scan tool function 03)

Note. The output Diagnostic Test Mode (DTM) can be activated only with the ignition switched on and the engine not running. The output DTM is interrupted if the engine is started, or if a rotary pulse from the ignition system is recognized. When operating in the output DTM, the individual output signals are actuated until the program sequence is advanced by pressing the --> button. Output signals are checked by listening for the sound of the component being actuated, or feeling for mechanical evidence of actuation, such as clicking, vibration, etc. Without letting the engine run, briefly switch the ignition off for approx. 20 seconds before repeating the output checks. During the entire output DTM sequence, the electric fuel pump will run. The output DTM will be interrupted after 10 minutes. Component locations, see COMPONENT LOCATIONS

The following components are actuated in sequence

1. Cylinder 1 fuel injector -N30
2. Cylinder 2 fuel injector -N31
3. Cylinder 3 fuel injector -N32
4. Cylinder 4 fuel injector -N33
5. Cylinder 5 fuel injector -N83
6. Cylinder 6 fuel injector -N84
7. EVAP canister purge regulator valve -N80
8. Secondary AIR solenoid valve -N112
9. Secondary AIR pump relay -J299
10. Intake manifold tuning valve -N156- (change-over valve)
11. Camshaft adjustment 1 (Valves -1- and -2- for camshaft adjustment, -N205- and -N208-)

Required special tools and testing equipment

VAG1551 Scan Tool (ST) with VAG1551/3 adapter cable

Test conditions

1. Fuse for Engine Control Module (ECM) OK
2. Closed Throttle Position (CTP) switch -F60- OK
3. Fuel pump relay OK

Test sequence

1. Connect VAG1551/VAG1552 scan tool and insert "Engine Electronics" address word 01 (ignition on). See «VAG1551/VAG1552 SCAN TOOL (ST), CONNECTING AND SELECTING "ENGINE ELECTRONICS" ADDRESS WORD 01»(/audi/a6/c5-1997-2001/remont/testing-diagnostics/#on-board-diagnostic-obd-28l-v6-aha__vag1551vag1552-scan-tool-st-connecting-and) .

Indicated on display

VAG Scan Tool Display - Output Diagnostic Test Mode, Scan Tool Function 03 (1 Of 3). Scheme 19

1. Press buttons -0- and -3- to select "Output Diagnostic Test Mode" function 03.

Indicated on display

VAG Scan Tool Display - Output Diagnostic Test Mode, Scan Tool Function 03 (2 Of 3). Scheme 20

Fuel injectors

1. Press -Q- button to confirm input.

Indicated on display

Note. The fuel pump relay must be activated, the fuel pump must run, and you must clearly hear the flow of fuel in the fuel pressure regulator. If the fuel pump does not run, check the fuel pump relay and connections. See FUEL PUMP RELAY AND CONNECTIONS, CHECKING .

1. Operate throttle valve at throttle body.

As soon as the Closed Throttle Position (CTP) switch opens, cylinder 1 fuel injector must be actuated (click) 5 times.

To check remaining fuel injectors

1. Press --> button and open throttle valve again. As soon as the Closed Throttle Position (CTP) switch opens, the applicable fuel injector must be actuated (click) 5 times.

1. Repeat for each fuel injector.

To skip individual tests

1. Press --> button to advance through program sequence.

If one or more of the fuel injectors is not actuated

1. Check fuel injectors. See «FUEL INJECTORS, CHECKING»(ref-216409-S26180814022006012100000) .

EVAP canister purge regulator valve -N80

1. Press --> button.

Indicated on display

VAG Scan Tool Display - EVAP Canister Purge Regulator Valve -N80. Scheme 21

The valve will click until the button is pressed to advance the program sequence.

If the valve is not actuated (does not click)

1. Check EVAP canister purge regulator valve. See «EVAPORATIVE EMISSIONS (EVAP) CANISTER PURGE REGULATOR VALVE -N80-, CHECKING»(ref-216409-S08340937162006012100000) .

Secondary Air Injection (AIR) solenoid valve -N112

1. Press --> button.

Indicated on display

VAG Scan Tool Display - Secondary Air Injection (AIR) Solenoid Valve -N112. Scheme 22

The valve will click until the --> button is pressed to advance the program sequence.

If the valve is not actuated (does not click)

1. Check secondary air injection solenoid valve -N112-. See «SECONDARY AIR INJECTION (AIR) SYSTEM, CHECKING»(ref-216409-S23092670842006012100000) .

Secondary Air Injection (AIR) pump relay -J299

1. Press --> button.

Indicated on display

VAG Scan Tool Display - Secondary Air Injection (AIR) Pump Relay -J299. Scheme 23

The relay will be actuated and turn on the secondary AIR pump motor until the --> button is pressed to advance the program sequence.

If the relay is not actuated (does not click) or the motor does not run

1. Check secondary air injection pump relay -J299-. See «SECONDARY AIR INJECTION (AIR) SYSTEM, CHECKING»(ref-216409-S23092670842006012100000) .

Intake manifold tuning valve -N156- (change-over valve)

1. Press --> button.

Indicated on display

VAG Scan Tool Display - Intake Manifold Tuning Valve -N156- (Change-Over Valve). Scheme 24

The valve will click until the button is pressed to advance the program sequence.

If the valve is not actuated (does not click)

1. Check intake manifold tuning valve -N156-. See «INTAKE MANIFOLD TUNING (IMT) VALVE, CHECKING»(ref-216409-S12716272132006012100000) .

Valves -1- and -2- for camshaft adjustment, -N205 -, - N208

1. Press --> button.

Indicated on display

VAG Scan Tool Display - Valves -1- And -2- For Camshaft Adjustment, -N205 -, - N208. Scheme 25

Valves 1 and 2 for camshaft adjustment, -N205- and -N208 -, are actuated (click) until the button is pressed to advance the program sequence.

If one of the valves is not actuated (does not click)

1. Check valves for camshaft adjustment. See «CAMSHAFT ADJUSTMENT SYSTEM, CHECKING»(/audi/a6/c5-1997-2001/remont/ignition-system/#ignitionglow-plug-system-28l-v6-aha) .
2. Press --> button.

Indicated on display

VAG Scan Tool Display - Select Function XX. Scheme 26

Note. Before selecting "Output Diagnostic Test Mode" function 03 again, switch the ignition off for approx. 20 seconds.

Basic Setting (scan tool function 04)

Note. The specified values for the "Basic Setting" and "Read Measuring Value Block" functions are described in the respective component test descriptions. Disconnecting the battery or the Engine Control Module (ECM) harness connector will erase all learned values and the readiness code. Diagnostic Trouble Code (DTC) memory, however, will not be erased. After reconnecting the battery and/or the ECM, the engine may idle unevenly and there may be some temporary loss of driveablity. If so, let the engine run at idle for a few minutes until the learning process has been completed. No learning will take place if a malfunction affecting engine regulation is stored in DTC memory (this does not include sporadic malfunctions). Basic settings are established with the engine running. In "Basic Setting" display groups 60 or 98, with the engine stopped and the ignition switched on, adaptation of the throttle valve control module -J338- takes place. Adaptation of throttle valve control module -J338- (with "Basic Setting" function 04 and display group 60), see THROTTLE VALVE CONTROL MODULE, ADAPTATION TO ENGINE CONTROL MODULE (ECM) . In "Basic Setting" display groups 88 or 99, oxygen sensor control is switched off. This makes it possible to check for malfunctions that may be caused by oxygen sensor control being switched on or off. In the selected display group, press buttons -4- and -8- to switch back and forth between "Read Measuring Value Block" function 08 and "Basic Setting" function 04.

Note. After selecting "Basic Setting" function 04, the ECM takes the following actions: EVAP canister purge regulator valve is closed A/C compressor is switched off

1. Vehicle stationary, engine running at idle
2. Accelerator pedal not depressed
3. Selector lever in "P" or "N" position
4. No malfunctions stored in DTC memory
5. Engine coolant temperature at least 80 °C (176 °F)
6. All electrical consumers switched off (coolant fan must not run during test)
7. A/C switched "OFF"

1. Connect VAG1551/VAG1552 Scan Tool (ST) and press buttons -0- and -1- to insert "Engine Electronics" address word 01 (engine running at idle). See «VAG1551/VAG1552 SCAN TOOL (ST), CONNECTING AND SELECTING "ENGINE ELECTRONICS" ADDRESS WORD 01»(/audi/a6/c5-1997-2001/remont/testing-diagnostics/#on-board-diagnostic-obd-28l-v6-aha__vag1551vag1552-scan-tool-st-connecting-and) .

Indicated on display

VAG Scan Tool Display - Basic Setting, Scan Tool Function 04 (1 Of 4). Scheme 27

1. Operate scan tool while observing messages on display.

Note. By pressing the HELP button an overview of possible functions will be printed out.

1. Press buttons -0- and -4- to select "Basic Setting" function 04, and press -Q- button to confirm input.

Indicated on display

VAG Scan Tool Display - Basic Setting, Scan Tool Function 04 (2 Of 4). Scheme 28

Note. Display group number 0 (000) is used as an example to demonstrate the procedure.

Changing Display Group Chart. Scheme 29

1. Press -0- button three times to input display group number 0 (000), and press -Q- button to confirm input.

Indicated on display

VAG Scan Tool Display - Basic Setting, Scan Tool Function 04 (3 Of 4). Scheme 30

Note. In display group 0 the measuring values are displayed in decimal form. The display can be printed out by pressing the PRINT button.

1. If specified values were attained in all display fields, Press --> button to advance through program sequence.

Indicated on display

VAG Scan Tool Display - Basic Setting, Scan Tool Function 04 (4 Of 4). Scheme 31

1. Press buttons -0- and -6- to select "End Output" function 06, and press -Q- button to confirm input.
2. If one of the specified values is not attained evaluation of display group 000. See «DISPLAY GROUP 000 - EVALUATION»(/audi/a6/c5-1997-2001/remont/testing-diagnostics/#on-board-diagnostic-obd-28l-v6-aha__display-group-000-evaluation) .
3. Continue by using procedures in "Corrective action" column.

Display Group 000 (Display In Decimal Values). Scheme 32

Display group 000 - evaluation

DISPLAY GROUP 000 -EVALUATION

VAG1598/22 test box, connecting

Note. If the Engine Control Module (ECM) is equipped with a metal anti-theft housing (for theft prevention), the metal anti-theft housing must be removed from the ECM to connect the test box. See ENGINE CONTROL MODULE (ECM) (WITH METAL ANTI-THEFT HOUSING), REPLACING . After repairs are complete, the metal anti-theft housing must be reinstalled. Switch the ignition off and wait at least 10 seconds before disconnecting the Engine Control Module (ECM) harness connector. Disconnecting the battery or the Engine Control Module (ECM) harness connector will erase all learned values and the readiness code. Diagnostic Trouble Code (DTC) memory, however, will not be erased. After reconnecting the battery and/or the ECM, the engine may idle unevenly and there may be some temporary loss of driveablity. If so, let the engine run at idle for a few minutes until the learning process has been completed.

1. Switch ignition off.
2. Disconnect ECM.
3. Connect VAG1598/22 adapter cable to ECM harness connector. see scheme 34: Connecting VAG1598/22 Adapter Cable To ECM Harness Connector
4. Generate readiness code. See «READINESS CODE, GENERATING»(/audi/a6/c5-1997-2001/remont/testing-diagnostics/#on-board-diagnostic-obd-28l-v6-aha).

Note. If the DTC memory has been erased or the ECM was disconnected from its power supply, a new readiness code must be generated. See READINESS CODE, GENERATING .

Engine Control Module (ECM) (without metal anti-theft housing), removing and installing

Removing ECMs with metal anti -theft housing. See ENGINE CONTROL MODULE (ECM) (WITH METAL ANTI-THEFT HOUSING), REPLACING .

Note. Switch the ignition off and wait at least 10 seconds before disconnecting the Engine Control Module (ECM) harness connector. Disconnecting the battery or the Engine Control Module (ECM) harness connector will erase all learned values and the readiness code. After reconnecting the battery and/or the ECM, the engine may idle unevenly and there may be some temporary loss of driveablity. If so, let the engine run at idle for a few minutes until the learning process has been completed. See BASIC SETTING (SCAN TOOL FUNCTION 04) . After installation of a new ECM, set ECM coding and perform adaptation of the Throttle valve control module - J338-.

Removing

If the ECM has to be replaced, perform the following steps in the sequence listed.

1. Connect VAG1551/VAG1552 Scan Tool (ST) and press buttons -0- and -1- to insert "Engine Electronics" address word 01 (with ignition switched on). See «VAG1551/VAG1552 SCAN TOOL (ST), CONNECTING AND SELECTING "ENGINE ELECTRONICS" ADDRESS WORD 01»(/audi/a6/c5-1997-2001/remont/testing-diagnostics/#on-board-diagnostic-obd-28l-v6-aha__vag1551vag1552-scan-tool-st-connecting-and) .

Indicated on display (ECM identification and coding)

VAG Scan Tool Display (ECM Coding, Example). Scheme 33

1. Print out ECM coding and compare with code table. See «ECM CODING VARIATIONS»(/audi/a6/c5-1997-2001/remont/testing-diagnostics/#on-board-diagnostic-obd-28l-v6-aha__ecm-coding-variations) .
2. Press --> button.

Indicated on display

VAG Scan Tool Display (Select Function XX). Scheme 34

1. Switch ignition off.
2. Remove plenum cover.
3. Remove cover of Electronic box (E-box). (Scheme 35): Removing ECM
4. Using screwdriver, carefully lift up mounting bracket (arrow).
5. Disconnect harness connector clips and remove ECM harness connector.

Installing

Install in the reverse order of removal noting the following

1. Check ECM coding. See «CODE CONTROL MODULE (SCAN TOOL FUNCTION 07)»(/audi/a6/c5-1997-2001/remont/testing-diagnostics/#on-board-diagnostic-obd-28l-v6-aha__code-control-module-scan-tool-function) .
2. Perform adaptation of Throttle valve control module -J388- to ECM. See «THROTTLE VALVE CONTROL MODULE, ADAPTATION TO ENGINE CONTROL MODULE (ECM)»(ref-216409-S01894933852006012100000) .
3. Generate readiness code. See «READINESS CODE, GENERATING»(/audi/a6/c5-1997-2001/remont/testing-diagnostics/#on-board-diagnostic-obd-28l-v6-aha) .

Note. If the DTC memory has been erased or the ECM was disconnected from its power supply, a new readiness code must be generated. See READINESS CODE, GENERATING .

Engine Control Module (ECM) (with metal anti-theft housing), replacing

Removing ECMs without metal anti -theft housing, see ENGINE CONTROL MODULE (ECM) (WITHOUT METAL ANTI-THEFT HOUSING), REMOVING AND INSTALLING .

Note. Adaptation values are erased when the harness connector is disconnected from the Engine Control Module (ECM), Diagnostic Trouble Code (DTC) memory content remains intact.

Scheme 35

1. Connect VAS5051 tester and select vehicle system "01 - Engine Electronics". Ignition must be switched on for this. (Scheme 36): VAS5051 Tester Display

VAS5051 tester display will indicate the control module identification and coding -2-.

Note. Always allow display of control module identification first and print it out.

Scheme 36

Scheme 37

Scheme 38

1. Switch ignition off.
2. Pull off of plenum chamber cover rubber seal in direction of arrow.
3. Remove cover -1- toward front. (Scheme 37): Removing Plenum Chamber Cover Rubber Seal
4. Remove cover for E-box, plenum chamber (arrows). (Scheme 38): Removing E-Box Plenum Chamber Cover
5. Using a screwdriver, carefully pry off retaining bracket (arrow). see scheme 41: Removing Bracket Of ECM With Antitheft Housing

Note. Item -1- in see scheme 41 shows Engine Control Module (ECM) with anti - theft housing.

To restrict accessibility (for theft prevention) to the harness connectors and the Engine Control Module (ECM), the ECM -1- is screwed to a metal anti-theft housing -4- via a locking mechanism -2- and snap-off screws -3-. (Scheme 39)

Removing ECM With Antitheft Housing. Scheme 39

The threads of the snap -off screws are coated with locking compound to make it more difficult to remove the snap -off screws.

To disconnect the harness connector from Engine Control Module (ECM) (e.g. when connecting a test box or when replacing the ECM), the ECM must be removed from the metal anti -theft housing. This procedure is described as follows.

The following equipment is required

Identifying Special Tools. Scheme 40

1. Heat gun -1- (from VAS1978 Wiring Harness Repair Kit)
2. Adapter nozzle -2- (also from VAS1978 Wiring Harness Repair Kit)
3. Standard locking pliers

Procedure

Scheme 41

1. "Flip" Engine Control Module (ECM) with anti-theft housing in direction of engine compartment so that locking mechanism (item -2- in illustration) becomes visible and place a clean rag below Engine Control Module (ECM) with anti-theft housing. (Scheme 41): Identifying ECM With Anti-Theft Housing
2. Adjust heat gun as shown in illustration, i.e. temperature adjustment -2- to maximum heat output and two-stage switch for air mass -3- to position 3. (Scheme 42): Adjusting Heat Gun

Note. Next, use a heat gun to heat the threads of the locking mechanism intowhich the snap-off screws are screwed. This step loosens the locking compound on the threads of the snap-off screws for easier removal.

Scheme 42

Scheme 43

1. Guide nozzle -1- of heat gun to locking mechanism threads so that nozzle "encloses" threads. It is OK to let nozzle make contact at upper end of metal anti -theft housing. (Scheme 43): Guiding Nozzle -1- Of Heat Gun To Locking Mechanism Threads
2. Switch on heat gun and heat up threads for approx. 20 to 25 seconds.
3. Next, using locking pliers -1-, grab screw head -2- and remove snap - off screw by turning in direction of arrow. (Scheme 44): Removing Snap Off Screws

Procedure for the second snap -off screw is exactly the same. Be very careful since the control module harness connector is in close proximity.

Scheme 44

Scheme 45

1. Guide nozzle -1- of heat gun to locking mechanism threads again so that nozzle "encloses" threads. It is OK to let nozzle make contact at upper end of metal anti -theft housing. (Scheme 45): Guiding Nozzle -1- Of Heat Gun To Locking Mechanism Threads
2. Switch on heat gun and heat up threads for approx. 20 to 25 seconds.
3. Next, using locking pliers -1-, grab screw head -2- and remove snap - off screw by turning in direction of arrow. see scheme 49: Removing ECM Snap Off Screws

The Engine Control Module (ECM) can now be removed from the metal anti-theft housing.

1. Disengage connectors from Engine Control Module (ECM) and then disconnect connectors.
2. Remove old Engine Control Module (ECM) and insert new one.

Installing Engine Control Module (ECM)

Installation is the reverse order of removal.

After repairs are complete the metal anti-theft housing must be reinstalled. Use new snap -off screws.

After connecting a new Engine Control Module (ECM), the following work steps must be performed

1. Activate Engine Control Module (ECM) in "Guided Troubleshooting" below the subject heading "Engine Control Module (ECM), replacing".

Use VAS5051 tester to do so .

Readiness code, checking

Note. The readiness code will be erased

1. When Diagnostic Trouble Code (DTC) memory is erased.
2. When the Engine Control Module (ECM) harness connector is disconnected (e.g. to connect the VAG1598/22 test box).
3. When the battery is disconnected.

VAG1551 Scan Tool (ST) with VAG1551/3 adapter cable

1. Connect VAG1551/VAG1552 Scan Tool (ST) and press buttons -0- and -1- to insert "Engine Electronics" address word 01 (with ignition switched on). See «VAG1551/VAG1552 SCAN TOOL (ST), CONNECTING AND SELECTING "ENGINE ELECTRONICS" ADDRESS WORD 01»(/audi/a6/c5-1997-2001/remont/testing-diagnostics/#on-board-diagnostic-obd-28l-v6-aha__vag1551vag1552-scan-tool-st-connecting-and) .

Indicated on display

VAG Scan Tool Display - Readiness Code Checking (1 Of 4). Scheme 46

1. Press buttons -0- and -8- to select "Read Measuring Value Block" function 08, and press -Q- button to confirm input.

Indicated on display

VAG Scan Tool Display - Readiness Code Checking (2 Of 4). Scheme 47

1. Press buttons -0-, -8- and -6- to input display group number 86 (086), and press -Q- button to confirm input.

Indicated on display (1 -4 - display fields)

VAG Scan Tool Display - Readiness Code Checking (3 Of 4). Scheme 48

1. Check readiness code values in display field 1. Specified value: 00000000

Note. The readiness code is generated as soon as only zeros are shown in display field 1.

1. Press --> button.

Indicated on display

VAG Scan Tool Display - Readiness Code Checking (4 Of 4). Scheme 49

1. Press buttons -0- and -6- to select "End Output" function 06, and press -Q- button to confirm input.

If the readiness code was not generated, generate readiness code again. See READINESS CODE, GENERATING .

1. Check readiness code. See «READINESS CODE»(/audi/a6/c5-1997-2001/remont/testing-diagnostics/#on-board-diagnostic-obd-28l-v6-aha) . If DTC memory has been erased, or ECM has been disconnected from B+, generate readiness code again. See «READINESS CODE, GENERATING»(/audi/a6/c5-1997-2001/remont/testing-diagnostics/#on-board-diagnostic-obd-28l-v6-aha) .

8 -Digit Readiness Code Explanation Chart. Scheme 50

VAG1551 Scan Tool (ST) with VAG1551/3 adapter cable

Test requirements

1. No malfunctions stored in DTC memory
2. Engine not stopped (ignition not switched off) during test
3. Vehicle not moving
4. All electrical consumers switched off (coolant fan must not run during test)

1. Connect VAG1551/VAG1552 Scan Tool (ST) and press buttons -0- and -1- to insert "Engine Electronics" address word 01 (with ignition switched on). See «VAG1551/VAG1552 SCAN TOOL (ST), CONNECTING AND SELECTING "ENGINE ELECTRONICS" ADDRESS WORD 01»(/audi/a6/c5-1997-2001/remont/testing-diagnostics/#on-board-diagnostic-obd-28l-v6-aha__vag1551vag1552-scan-tool-st-connecting-and) .

Step 1: Check DTC memory

Indicated on display

Checking DTC Memory With VAG Scan Tool (1 Of 2). Scheme 51

1. Press buttons -0- and -2- to select "Check DTC Memory" function 02, and press -Q- button to confirm input.

Indicated on display

Checking DTC Memory With VAG Scan Tool (2 Of 2). Scheme 52

If one or more DTCs are stored

1. Repair cause of malfunction.
2. Erase DTC memory.
3. Stop engine, start engine again, and road test vehicle, safety precautions for road testing vehicle. See «SAFETY PRECAUTIONS»(ref-216409-S10796765012006012100000) .
4. Check DTC memory again and erase.

If no DTCs were recognized

1. Press --> button.

Step 2: Erase DTC memory

Indicated on display

Erasing DTC Memory With VAG Scan Tool (1 Of 2). Scheme 53

1. Press buttons -0- and -5- to select "Erase DTC Memory" function 05, and press -Q- button to confirm input.

Note. When erasing DTC memory, the readiness code is also erased.

Indicated on display

Erasing DTC Memory With VAG Scan Tool (2 Of 2). Scheme 54

1. Press --> button.

Step 3: Adaptation of throttle valve control module to ECM

Indicated on display

VAG Scan Tool Display - Adaptation Of Throttle Valve Control Module To ECM (1 Of 4). Scheme 55

1. Press buttons -0- and -8- to select "Read Measuring Value Block" function 08, and press -Q- button to confirm input.

Indicated on display

VAG Scan Tool Display - Adaptation Of Throttle Valve Control Module To ECM (2 Of 4). Scheme 56

1. Press buttons -0-, -6- and -0- to input display group number 60 (060), and press -Q- button to confirm input.

Indicated on display (1 -4 = display fields)

VAG Scan Tool Display - Adaptation Of Throttle Valve Control Module To ECM (3 Of 4). Scheme 57

1. Press button -4- to select "Basic Setting" function 04 (adaptation of throttle valve control module to ECM)

Indicated on display (1 -4 = display fields)

VAG Scan Tool Display - Adaptation Of Throttle Valve Control Module To ECM (4 Of 4). Scheme 58

1. Check specified values in display fields 3 and 4: DISPLAY GROUP 60: ADAPTATION OF THROTTLE VALVE CONTROL MODULE TO ENGINE CONTROL MODULE (ECM) Display fields 1 2 3 4 Display group 60: Adaptation of throttle valve control module to Engine Control Module (ECM) Display xxx ANGLE ° xxx ANGLE ° Idle ADP.runs Part Throt ADP. OK Full Throt ADP.ERROR Decel Enrich Indicated Throttle valve angle Throttle drive angle Operating condition Adaptation status Specified value --- --- Idle ADP. OK

If "ADP. ERROR" is indicated in display field 4

1. Check DTC memory. See «CHECK DTC MEMORY (SCAN TOOL FUNCTION 02)»(/audi/a6/c5-1997-2001/remont/testing-diagnostics/#on-board-diagnostic-obd-28l-v6-aha) .

If the specified value "ADP. OK" is indicated in display field 4

1. Press --> button.

Step 4

1. Start engine and let run at idle.

Step 5: Oxygen Sensor (O2S) control operating condition

Indicated on display

VAG Scan Tool Display - Oxygen Sensor Control Operating Condition (1 Of 3). Scheme 59

1. Press buttons -0- and -8- to select "Read Measuring Value Block" function 08, and press -Q- button to confirm input.

Indicated on display

VAG Scan Tool Display - Oxygen Sensor Control Operating Condition (2 Of 3). Scheme 60

1. Press buttons -0-, -3- and -0- to input display group number 30 (030), and press -Q- button to confirm input.

Indicated on display (1 -4 = display fields)

VAG Scan Tool Display - Oxygen Sensor Control Operating Condition (3 Of 3). Scheme 61

1. Increase engine speed to 1800-2200 RPM.
2. Hold at 1800-2200 RPM until specified value "111" is shown in all of display fields 1 -4. See «STEP 6: OXYGEN SENSOR (O2S) AGING (TIME PERIOD)»(/audi/a6/c5-1997-2001/remont/testing-diagnostics/#on-board-diagnostic-obd-28l-v6-aha__step-6-oxygen-sensor-o2s-aging) . DISPLAY GROUP 30: OXYGEN SENSOR (O2S) CONTROL OPERATING CONDITION, BANK 1 AND BANK 2 DISPLAY FIELDS Display fields 1 2 3 4 Display group 30: Oxygen Sensor (O2S) control operating condition, Bank 1 and Bank 2 Display xxx xxx xxx xxx Indicated Status of Heated Oxygen Sensor (HO2S), bank 1, sensor 1, before TWC Status of Heated Oxygen Sensor (HO2S) 2, bank 1 sensor 2, after TWC Status of Heated Oxygen Sensor (HO2S), bank 2, sensor 1, before TWC Status of Heated Oxygen Sensor (HO2S) 2, bank 2 sensor 2, after TWC Specified value 111 111 111 111 Evaluation, see «STEP 6: OXYGEN SENSOR (O2S) AGING (TIME PERIOD)»(/audi/a6/c5-1997-2001/remont/testing-diagnostics/#on-board-diagnostic-obd-28l-v6-aha__step-6-oxygen-sensor-o2s-aging)

If one of the specified values is not indicated

1. Check DTC memory. See «CHECK DTC MEMORY (SCAN TOOL FUNCTION 02)»(/audi/a6/c5-1997-2001/remont/testing-diagnostics/#on-board-diagnostic-obd-28l-v6-aha) .

If the specified values for display fields 1 --4 are not indicated

1. Continue to hold engine speed at 1800-2200 RPM. Explanation of 3 -digit value in display fields 1 through 4: EXPLANATION OF 3 -DIGIT VALUE IN DISPLAY FIELDS 1 THROUGH 4 When display = 1 1 2 3 1 Oxygen Sensor (O2S) control active 1 Heated Oxygen Sensor (HO2S) operational 1 Oxygen Sensor (O2S) heater ON

Step 6: Oxygen Sensor (O2S) aging (time period)

1. Press button -4- to select "Basic Setting" function 04.
2. Press button -3- four times to advance to display group number 34.

Indicated on display (1 -4 = display fields)

VAG Scan Tool Display - Sensor (O2S) Aging, Time Period. Scheme 62

1. Hold engine speed at 1800 -2200 RPM until display changes from "Test OFF" to "Test ON" in display field 4.
2. Continue to hold at 1800 -2200 RPM until specified value "B1-S1. OK" is indicated in display field 4. DISPLAY GROUP 34: OXYGEN SENSOR AGING, BANK 1 (TIME PERIOD OF OXYGEN SENSOR) Display fields 1 2 3 4 Display group 34: Oxygen sensor aging, Bank 1 (time period of oxygen sensor) Display xxxx RPM xx.xx ms xx.xx s Test OFF/Test ON B1-S1 OK/ B1-S1 n. OK Indicated Engine speed (increments of 40 RPM) Engine load Time period of HO2S before TWC, Bank 1, Sensor 1 Diagnostic status Diagnostic result Range 0-6800 RPM 0.00-12.75 ms 0.00-5.00 s --- Specified value 1800 - 2200 RPM 0.80-2.00 ms 0.20-2.10 s B1-S1 OK

If "B1-S1 n. OK" is indicated in display field 4

1. Check DTC memory. See «CHECK DTC MEMORY (SCAN TOOL FUNCTION 02)»(/audi/a6/c5-1997-2001/remont/testing-diagnostics/#on-board-diagnostic-obd-28l-v6-aha) .

If the specified value "B1 -S1 OK" is indicated in display field 4

1. Continue to hold engine speed at 1800 --2200 RPM.
2. Press button -3- once to advance to display group number 35.

Indicated on display (1 -4 = display fields)

VAG Scan Tool Display - Basic Setting 35. Scheme 63

1. Hold engine speed at 1800 -2200 RPM until display changes from "Test OFF" to "Test ON" in display field 4.
2. Continue to hold at 1800 -2200 RPM until specified value "B2-S1 OK" is indicated in display field 4. DISPLAY GROUP 35: OXYGEN SENSOR AGING, BANK 2 (TIME PERIOD OF OXYGEN SENSOR) Display fields 1 2 3 4 Display group 35: Oxygen sensor aging, Bank 2 (time period of oxygen sensor) Display xxxx RPM xx.xx ms xx.xx s Test OFF/Test ON B2-S1 OK/ B2-S1 n. OK Indicated Engine speed (increments of 40 RPM) Engine load Time period of HO2S before TWC, Bank 2, Sensor 1 Diagnostic status Diagnostic result Range 0-6800 RPM 0.00 -12.75 ms 0.00-5.00 s --- Specified value 1800 - 2200 RPM 0.80-2.00 ms 0.20-2.10 s B2-S1 OK

If "B2-S1 n. OK" is indicated in display field 4

1. Check DTC memory. See «CHECK DTC MEMORY (SCAN TOOL FUNCTION 02)»(/audi/a6/c5-1997-2001/remont/testing-diagnostics/#on-board-diagnostic-obd-28l-v6-aha) .

If the specified value "B2 -S1 OK" is indicated in display field 4

1. Continue to hold engine speed at 1800 --2200 RPM.
2. Press -C- button.

Step 7: Three Way Catalytic Converter (TWC) diagnosis

Indicated on display

VAG Scan Tool Display - Three Way Catalytic Converter Diagnosis (1 Of 2). Scheme 64

1. Press buttons -0-, -4- and -6- to input display group number 46 (046), and press -Q- button to confirm input.

Indicated on display (1 --4 = display fields)

VAG Scan Tool Display - Three Way Catalytic Converter Diagnosis (2 Of 2). Scheme 65

1. Hold engine speed at 1800 -2200 RPM until display changes from "Test OFF" to "Test ON" in display field 4.
2. Continue to hold at 1800 -2200 RPM until specified value "Cat B1 OK" is indicated in display field 4.

Note. The test time for TWC diagnosis is approx. 60 seconds.

DISPLAY GROUP 46: THREE WAY CATALYTIC CONVERTER (TWC), BANK 1 DIAGNOSIS

If "Cat B1 n. OK" is indicated in display field 4

1. Check DTC memory. See «CHECK DTC MEMORY (SCAN TOOL FUNCTION 02)»(/audi/a6/c5-1997-2001/remont/testing-diagnostics/#on-board-diagnostic-obd-28l-v6-aha) .

If specified value "Cat B1 OK" is indicated in display field 4

1. Continue to hold engine speed at 1800 --2200 RPM.
2. Press button -3- once to advance to display group number 47.

Indicated on display (1 -4 = display fields)

VAG Scan Tool Display - Basic Setting 47. Scheme 66

1. Hold engine speed at 1800 -2200 RPM until display changes from "Test OFF" to "Test ON" in display field 4.
2. Continue to hold at 1800 -2200 RPM until specified value "Cat B2 OK" is indicated in display field 4.

Note. The test time for TWC diagnosis is approx. 60 seconds.

DISPLAY GROUP 47: THREE WAY CATALYTIC CONVERTER (TWC), BANK 2 DIAGNOSIS

If "Cat B2 n. OK" is indicated in display field 4

1. Check DTC memory. See «CHECK DTC MEMORY (SCAN TOOL FUNCTION 02)»(/audi/a6/c5-1997-2001/remont/testing-diagnostics/#on-board-diagnostic-obd-28l-v6-aha) .

If specified value "Cat B2 OK" is indicated in display field 4

1. Press -C- button.

Step 8: Evaporative Emissions (EVAP) system and fuel tank leak detection

Note. During this diagnosis there should be no engine load, otherwise the diagnosis is interrupted and can only be restarted after pressing the accelerator pedal momentarily.

1. Start engine and let run at idle.

Indicated on display

VAG Scan Tool Display - EVAP System And Fuel Tank Leak Detection (1 Of 2). Scheme 67

1. Press buttons -0-, -7- and -0- to input display group number 70 (070), and press -Q- button to confirm input.

Indicated on display (1 -4 = display fields)

VAG Scan Tool Display - EVAP System And Fuel Tank Leak Detection (2 Of 2). Scheme 68

If the diagnosis is initiated by the ECM, the display changes from "Test OFF" to "Test ON" in display field 4.

1. Let engine continue to run at idle until specified value "EVAP OK" is indicated in display field 4.

Note. If the display changes from "Test ON" to "Test OFF" during the diagnosis, briefly accelerate the engine to reset and repeat the test.

DISPLAY GROUP 70: EVAPORATIVE EMISSIONS (EVAP) CANISTER PURGE REGULATOR VALVE DIAGNOSIS

If "EVAP n. OK" is indicated in display field 4

1. Check DTC memory. See «CHECK DTC MEMORY (SCAN TOOL FUNCTION 02)»(/audi/a6/c5-1997-2001/remont/testing-diagnostics/#on-board-diagnostic-obd-28l-v6-aha) .

If the specified value "EVAP OK" is indicated in display field 4

1. Press -3- button to input display group number 71.

Indicated on display (1 -4 = display fields)

VAG Scan Tool Display - Basic Setting 71. Scheme 69

1. Start engine and let run at idle.

If the diagnosis is initiated by the ECM, the display changes from "Test OFF" to "Test ON" in display field 4.

1. Let engine continue to run at idle until specified value "Syst. OK" is indicated in display field 4. DISPLAY GROUP 71: FUEL TANK LEAK DETECTION Display fields 1 2 3 4 Display group 71: Fuel tank leak detection Display Reed op. Small leak/large leak Syst.Test Test OFF/Test ON Reed cl. disconnection Check Syst. OK Check end Syst. n.OK/ Indicated Status: Reed contact Error message System status Diagnostic status Diagnostic result Range --- --- --- --- Specified value Reed op. --- Check end Syst. OK

Note. If display field 4 changes from "Test ON" to "Test OFF" and "Abort" appears in display field 2, repeat the diagnosis of fuel tank leak detection. Shut the engine off, start the engine again and repeat the leak detection test.

Diagnosis conditions for fuel tank leak detection

1. Intake Air Temperature (IAT) must be less than 60 C (140 F), Display group 004, display field 4. See «INTAKE AIR TEMPERATURE (IAT) SENSOR, CHECKING»(ref-216409-S41232244122006012100000) . The temperature can be reduced by opening the hood.
2. The throttle valve angle for vehicles with automatic transmissions must be smaller than 10 display group 003, display field 3. See «THROTTLE POSITION (TP) SENSOR, CHECKING»(ref-216409-S37351594562006012100000) .
3. The throttle valve angle for vehicles with manual transmissions must be smaller than 10 display group 003, display field 3. See «THROTTLE POSITION (TP) SENSOR, CHECKING»(ref-216409-S37351594562006012100000) .

If "Syst. n. OK" is indicated in display field 4

1. Check DTC memory. See «CHECK DTC MEMORY (SCAN TOOL FUNCTION 02)»(/audi/a6/c5-1997-2001/remont/testing-diagnostics/#on-board-diagnostic-obd-28l-v6-aha) .

If the specified value "Syst. OK" is indicated in display field 4

1. Press --> button.

Step 9: Secondary Air Injection (AIR) system diagnosis

1. Start engine and let run at idle.

Indicated on display

VAG Scan Tool Display - Secondary Air Injection (AIR) System Diagnosis (1 Of 2). Scheme 70

1. Press buttons -0-, -7- and -7- to input display group number 77 (077), and press -Q- button to confirm input.

Indicated on display (1 -4 = display fields)

VAG Scan Tool Display - Secondary Air Injection (AIR) System Diagnosis (2 Of 2). Scheme 71

If the diagnosis is initiated by the ECM, the display changes from "Test OFF" to "Test ON" in display field 4.

1. Let engine continue to run at idle until specified value "Syst. OK" is indicated in display field 4. DISPLAY GROUP 77: SECONDARY AIR INJECTION SYSTEM DIAGNOSIS Display fields 1 2 3 4 Display group 77: Secondary air injection system diagnosis Display xx.x % xx.x % xx.x °C Test OFF/Test ON Syst. OK/ Syst. n.OK Indicated O2S control deviation during diagnostics O2S control deviation during diagnostics Coolant temperature Diagnostic status Bank 1 Bank 2 Diagnostic result Range --- --- -46.5 to +141.5 ° C --- Specified value --- --- greater than 70.0 ° C Syst. OK

If "Syst. n. OK" is indicated in display field 4

1. Check DTC memory. See «CHECK DTC MEMORY (SCAN TOOL FUNCTION 02)»(/audi/a6/c5-1997-2001/remont/testing-diagnostics/#on-board-diagnostic-obd-28l-v6-aha) .

If the specified value "Syst. OK" is indicated in display field 4

1. Press --> button.

Step 10: Check readiness code

1. Check readiness code. See «READINESS CODE»(/audi/a6/c5-1997-2001/remont/testing-diagnostics/#on-board-diagnostic-obd-28l-v6-aha) .

See also:
• MISFIRE RECOGNITION, CHECKING
• EVAP CANISTER SYSTEM
• CAMSHAFT POSITION (CMP) SENSOR -G40-, CHECKING
• CAMSHAFT POSITION (CMP) SENSOR 2 -G163-, CHECKING
• CHECK DTC MEMORY (SCAN TOOL FUNCTION 02)
• VAG1551/VAG1552 SCAN TOOL (ST), CONNECTING AND SELECTING "ENGINE ELECTRONICS" ADDRESS WORD 01
• ECM CODING VARIATIONS
• ENGINE CONTROL MODULE (ECM) (WITHOUT METAL ANTI-THEFT HOUSING), REMOVING AND INSTALLING
• DIAGNOSTIC TROUBLE CODE (DTC) TABLE
• OUTPUT DIAGNOSTIC TEST MODE (SCAN TOOL FUNCTION 03)
• CODE CONTROL MODULE (SCAN TOOL FUNCTION 07)
• MALFUNCTION INDICATOR LAMP (MIL) FUNCTION, CHECKING
• DISPLAY GROUP 000 - EVALUATION
• ENGINE CONTROL MODULE (ECM) (WITH METAL ANTI-THEFT HOUSING), REPLACING
• BASIC SETTING (SCAN TOOL FUNCTION 04)
• STEP 6: OXYGEN SENSOR (O2S) AGING (TIME PERIOD)