Test sequence

WARNING: This page is about a different variant/trim than selected.

Connect Scan Tool VAG1551 ( VAG1552 ) and select engine electronics control unit. Run engine at idle speed and press buttons 0 and 1 to select "Engine electronics" address word 01. (Connecting Scan Tool and selecting engine electronics control unit → Scan Tool VAG1551 , connecting .)

CAUTION: Secure Scan Tool to rear seat and operate from this position (second technician required).

Indicated on display:

Rapid data transfer HELP
Select function XX

Press buttons 0 and 8 for the function "Read measured value block" and confirm entry with Q button.

Indicated on display:

Read measured value block
Enter display group number XXX

Press buttons 0 , 1 and 0 for "Display group number 10" and confirm entry with Q button.
Observe display in display field 1.

Specification: 230 to 370 mg/H

Read measured value block 10 →
309 mg/H 1027 mbar 1011 mbar 0.0 %

If the specification is not obtained:

Check exhaust gas recirculation: → 26 - EXHAUST SYSTEM, EMISSION CONTROLS

If the specification is obtained:

Road test vehicle with a 2nd technician to observe display.

Observe valid safety precautions when road testing → Safety precautions .

Accelerate vehicle in 3rd gear (vehicles with manual transmission) or 2nd gear (vehicles with automatic transmission) from about 1500 rpm using wide open throttle.
Press PRINT button on VAG1551 at approx. 3000 rpm. The accelerator pedal must be fully depressed at this moment in time.

Specification in display field 4: 100% (accelerator pedal position/throttle)

Read measured value block 10 →
830 mg/H 1027 mbar 1850 mbar 100 %

If the specification is not obtained:

Repeat test and accelerate vehicle at wide open throttle.

Specification in display field 1: above 800 mg/H (mass air flow drawn in).

Read measured value block 10 →
830 mg/H 1027 mbar 1850 mbar 100 %

If the specification is not obtained:

Press the → button.
Press buttons 0 and 6 to select "End output" function 06 and confirm entry with the Q button.
Switch off ignition.
Replace MAF sensor.

Check DTC memory and, if necessary, repair any malfunctions and then erase → Diagnostic Trouble Code (DTC) memory, checking and erasing .
Read readiness code → Reading readiness code . If the DTC memory has been erased, the readiness code must be generated again → Readiness code, setting .

If a constant 550 mg/H (predetermined replacement value) is displayed in display field 1.

Press the → button.
Press buttons 0 and 6 for the function "End output" and confirm entry with the Q button.
Switch off ignition.

Fig 1: Locating MAF Sensor

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Pull 5-pin connector off MAF sensor - arrow -.
Switch on ignition.

Fig 2: 5-Pin Connector & Terminals

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Measure MAF sensor voltage supply between following connector contacts:

Terminal on G70	Specification
2 + Ground	App. battery voltage
2 + 3	App. battery voltage
4 + Ground	Approx. 5 V
4 + 3	Approx. 5 V

If specifications are not obtained:

Switch off ignition.
Remove wiper arms and plenum cover: → 92 WINDSHIELD WIPER & WASHER SYSTEM

Fig 3: Identifying Test Box V.A.G 1598/31 Connected To Control Module Wiring Harness

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Connect test box VAG1598/31 to control module wiring harness.

Fig 4: 5-Pin Connector & Terminals

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Check wiring between test box and connector for open circuit using wiring diagram.

Terminal 2+ socket 1 and 2

Terminal 3+ socket 49

Terminal 4+ socket 30

Terminal 5+ socket 68

Wire resistance: max. 1.5 Ω

Check wires for short to one another, to vehicle Ground and to battery positive (B+).

Specification: ∞Ω

If no malfunction is detected in the wiring:

Replace Diesel Direct Fuel Injection (DFI) Engine Control Module (ECM) J248 → Diesel Direct Fuel Injection (DFI) Engine Control Module (ECM) J248 , replacing .