Failing inspection

Hi and thanks for using 2CarPros.

If there are no lights on, has anyone told you why it is failing? Also, you replaced a few things already, was there a trouble code indicating a cooling system issue? I'm not sure why they wouldn't tell you why it won't pass.

Although there are no lights on, I suggest using a scanner to determine if something is pending or stored.

Also, are they telling you maybe the one of the components haven't yet reset?
Let me know the answers to the aforementioned questions.

Take care,
Joe

Welcome back:
If the code was deleted and it came back, confirm the connector isn't damaged and is properly installed. The small pins in them can get corroded or damaged.

Now, it that isn't the problem, then you have to go through a list of diagnostic tests to determine the problem. It requires a VAG scanner, and a few other general tools. I will provide them for you. If you don't have the proper test equipment, most likely this won't be helpful. I hate to say that, but it's the bottom line. And, to determine what is causing the problem, these are the tests that need done. However, some of the testing is done using a multi meter. Here are a few links that may help:

https://www.2carpros.com/articles/how-to-use-a-voltmeter

https://www.2carpros.com/articles/how-to-use-a-test-light-circuit-tester

https://www.2carpros.com/articles/how-to-check-wiring

The attached pictures correlate with these directions.

MASS AIR FLOW (MAF) SENSOR, CHECKING
Mass Air Flow (MAF) Sensor, Checking

Special tools and equipment
- VAG 1551 Scan Tool or VAG 1552 with cable VAG 1551/3
- Test box VAG 1598/22
- Hand multimeter VAG 1526 or multimeter VAG 1715
- Adapter set VAG 1594
- Wiring diagram

Check conditions
- Coolant temperature must be at least 80 degree C, see display group 04, display zone 3.
- All electrical consumers, e.g. lights and rear window heating must be switched off
- If the vehicle is equipped with an air conditioner, this must be switched off.
- On vehicles with automatic transmission selector lever in "P" or "N" position

Test sequence
- Connect VAG 1551 Scan Tool ((VAG 1552). Start engine and select "Address word" 01 of engine control module. Engine must be running at idle speed. (Connecting scan tool and selecting engine control module See: Computers and Control Systems > Reading and Clearing Diagnostic Trouble Codes > Connecting VAG Scan Tool 1551/1552).

Indicated on display

Rapid data transfer HELP
Select function XX

- Press keys 0 and 8 for function "Read Measuring Value Block" and confirm entry with Q key.

Indicated on display

Read Measuring Value Block HELP
Input display group number XXX

- Press keys 0, 0 and 5 for "Display group number 5" and confirm entry with Q key.

Indicated on display: (1 to 4 = Display zones)

Read Measuring Value Block 5 ->
1 2 3 4

- Observe idling switch operating mode in display zone 4. As long as engine is running at idling, idling must be displayed
Display: Idling

If the specification is not obtained:
- Check idling switch, checking throttle valve control module.

If the specification is obtained:
- Press C key.
- Press keys 0, 0 and 2 for "Display group number 2" and confirm entry with Q key.

Indicated on display: (1 to 4 = Display zones)

Read Measuring Value Block 2 ->
1 2 3 4

- Check mass of air drawn in in display zone 4
Specification: 2.0 to 5.0 g/s

If the specification is obtained but there is a malfunction regarding Mass Air Flow (MAF) sensor registered in the DTC memory:
- Check voltage supply for Mass Air Flow (MAF) sensor.

If the specification is not obtained:
- Check signal and Ground wires for Mass Air Flow (MAF) sensor.

If the specification is obtained:
- Press -> key.
- Press keys 0 and 6 for "End Output" function and confirm input with Q key.
- Switch ignition off.

Testing power supply to Mass Air Flow (MAF) sensor

Picture 1

- Pull 5 pin connector -1- off Mass Air Flow (MAF) sensor -2-.
- Connect multimeter to measure voltage on connector contact 2 and engine Ground.
- Start engine and run at idle speed.
Specification: 11 to 15 V

If no voltage is present:
- Switch ignition off.
- Check wiring from contact 2 to fuel pump (FP) relay -J17- according to wiring diagram.

If the voltage supply and wiring is OK:
- Switch ignition on.
- Connect multimeter to measure voltage on connector contact 4 and engine Ground:
Specification: 4.5 to 5.5 V

If no voltage is present:
- Switch ignition off.
- Check signal and Ground wires.

Testing signal and Ground wires for Mass Air Flow (MAF) sensor

Picture 2

- Connect test box VAG 1598/22 to control module wiring harness.

Picture 3

- Check wiring between test box and 5 pin connector for open circuit using wiring diagram.
Contact 5 + socket 13
Contact 4 + socket 11
Contact 3 + socket 12
Wire resistance: Max. 1.5 Ohm
- Additionally check wires all for short to one another.
Specification: Infinite Ohm
- Additionally check the wiring for short to battery positive or Ground.

If no wiring malfunction is detected:
- Replace Mass Air Flow (MAF) sensor -G70-.

___________________________________________________

Let me know if this helps or if you have other questions.

Joe