need help with an audi a4

[mariod987]

i have a 2005 audi a4 quattro, my problem started one day when i filled up the tank with gas, when it came time to start the car up. the engine would turn over but

Topic

[jacobnbr1]

This problem is likely a bit complex for a DIY situation but be advised there are three TSBs that apply to that vehicle.

1st p0089 (In most cases is the g410 fuel pressure sensor)Refer to TSB# 01-07-69 (VW) and 24-08-56 (Audi) for further information on Low Pressure Side Fuel Pressure Sensor G410 diagnostics. 1. Verify low pressure side fuel pressure at the schrader valve on the high pressure fuel pump. The Fuel Pump Control Module J538 controls the operation of the fuel pump by a pulse width modulated signal. J538 regulates the pressure in the low pressure fuel system between 0.5 – 5 bar (7.3 – 72.5 PSI). The pressure is increased to 6.5 bar (94.3 PSI) during hot or cold startups.

2. With a factory compatible scan tool:

A. Start the vehicle and run it at an idle.

B. Disconnect Fuel Metering Valve N276 electrical connector on the high pressure fuel pump.

C. Select Address Word 01-Engine Management Master. Select Function 08-Read Measuring Value Blocks (MVB). Compare Display Group 103 field 1 (actual fuel pressure in mbar) and Display Group 106 field 1 (fuel rail pressure in bar).

D. If MVB 103 deviates than +/- 0.5 bar (7.25 PSI) from MVB 106, then the issue is most likely caused by the Low Pressure Fuel Pressure Sensor G410.

E. After replacement of G410 sensor, Function 04-Basic Settings will need to be selected. Display Group 103 will need to be activated. The vehicle will need to sit with the Key On Engine Off (KOEO) until field 4 shows “ADP.OK”.

3. With a fuel pressure gauge (a factory compatible scan tool is still required):

A. Read the fuel pressure gauge at idle. Add 1 bar (14.5 PSI) to the value obtained from the mechanical gauge.

B. Compare the mechanical gauge reading to the reading in MVB 103 field 1. (MVB 103 field 1 should be approximately 1 bar (14.5 PSI) above mechanical gauge reading.)

C. After Low Pressure Side Fuel Pressure Sensor G410 replacement; Function 04-Basic Settings will need to be selected. Display Group 103 will need to be activated. The vehicle will need to sit with the Key On Engine Off (KOEO) until field 4 shows “ADP.OK”.

4. If there is difficulty running Basic Setting 103, drive the vehicle continuously for 0.5 hours to manually perform basic setting.

2nd p0299
1. Refer to TSB 21/07/02 for replacement of turbocharger recirculation valve with new style valve.

2. Refer to TSB 01/07/18 for reflash of powertrain control module with improved software.

3rd p0455 large evap leak ( In most cases is the n80 canister purge solenoid.)
Tests: Test the N80 Canister Control Valve (CCV) function as follows:

1. Cool the valve in a freezer and then manually energize it by applying power and ground to the valve.

2. Make sure that the valve opens and closes fully and does not stick. Repeat the test with the valve heated to underhood operating temperature.

3. The valve must open and close fully and never stick.

4. Check the vacuum and vapor lines, from the N80 valve to the canister, for leakage or damage.

Test the Leak Detection Pump (LDP) function as follows:

1. At the LDP, disconnect the electrical connector.

2. Apply B+ to terminal 3 of the LDP (terminal 3 is where the Green/Yellow (GN/GE) wire would connect).

3. Apply ground to terminal 2 of the LDP (terminal 2 is where the Grey/Red (GR/RO) wire would connect).

4. Apply vacuum to a small line vacuum nipple (this should hold vacuum).

5. The purge filter should now be sealed off.
4th p0172 Is a very complex test.

• Connect pressure gauge V.A.G 1318 to fuel supply line using adapter V.A.G 1318/11 and V.A.G 1318/12.
• Connect bleed hose – arrow – to the Pressure Gauge V.A.G 1318 and hold it in a measuring container.
• Open shut-off valve of pressure gauge V.A.G 1318 . The shut off valve lever points in the direction of flow.
• Bleed fuel system by pressing remote control briefly.

• Close shut-off valve on Pressure Gauge V.A.G 1318 . The shut off valve lever points in the direction of flow. – arrow – .
• Hold switch of the remote control until no more pressure increase is observed on the Pressure Gauge V.A.G 1318 .
• Specified value: approx. 6 bar (5 to 7 bar) positive pressure.

If specification is not obtained:

• Check delivery rate of fuel pump.

Checking residual pressure

• Check for leaks and residual pressure by observing pressure drop on Pressure Gauge V.A.G 1318.
• After 10 minutes there must be a residual pressure of at least 3.75 bar .

The holding pressure drops below 3.75 bar :

• Check connection between fuel Pressure Gauge V.A.G 1318 and fuel line for leaks.
• Check Pressure Gauge V.A.G 1318 for leaks.
• Check fuel lines and their connections for leaks.
• Replace fuel filter with integrated fuel pressure regulator.
• If the fuel filter is OK, replace fuel pump.

[EricTheCarGuy]

Jacobnbr1 has some great suggestions and I stand by them but just for the heck of it I might just try holding your foot to the floor while you crank the engine, it could just be flooded and holding the gas to the floor will put the engine is clear flood mode which might help it start. Other than Jacobnr1’s suggestions check the basics like spark, fuel, and engine mechanical. Good luck.

[Matt]

I just wanted to say that jacob, you are awesome for submitting these service information answers that aren’t available to the general public. Keep it up boss 🙂

[pcmdjason]

This sounds like when RealFixesRealFast did a 3 part video on symptoms, evidence and solution where they gave you a bunch of codes, waited several days and let you guess.

[Trcustoms719]

loose or bad gas cap can cause EVAP codes.
That’s the first thing i would check.

[Author]

Replies