Audi Q7 Quattro Technical 240928 Date: 091218
Fuel System - MIL ON/Multiple Fuel Pressure DTC's Set
01 MIL on (DTC P310B, P129F, P008B, P129E, P008A, P2540, P0087)
24 09 28
2022132/1
December 18, 2009
Affected Vehicles
Condition
MIL on and one or more of the following DTCs are stored in the ECM data memory:
^ P310B (Low-pressure fuel system regulation, fuel pressure outside tolerance)
^ P129F or P008B (low-pressure fuel system, pressure too high)
Audi Q7 Quattro 253
^ P129E or P008A (low pressure fuel system, pressure too low)
^ P2540 (low pressure fuel system, pressure out of range)
^ P0087 (rail fuel pressure system, pressure too low)
Technical Background
Comparing Measure Value Block 103 with 106 is not an accurate method to diagnose low-side fuel pressure sensor G410.
In order to diagnose G410 accurately, use a mechanical gauge and compare results with the low-side fuel pressure Actual Value in the applicable
Measured Value Block (varies by engine).
Production Solution
Not applicable.
Service
1. Verify the customer did not run out of fuel at the time the DTCs were stored.
Tip:
P310B and/or P129E / P008A may be accompanied by P1250. If so, it is likely the faults occurred due to a low fuel level and not a malfunction of
the G410 Pressure Sensor.
2. Follow indication of GFF for applicable DTCs.
3. To check the low-side fuel pressure sensor G410, measure the fuel pressure with a mechanical gauge using the following method:
a. Start engine and allow to idle for at least one minute.
b. Stop the engine.
c. Keep the ignition on.
d. Measure actual low-side fuel pressure via mechanical gauge (VAG 1318) on the low pressure supply line in the engine compartment (Figure 1).
4. Add 1 bar to the value obtained from the mechanical gauge to calculate the adjusted gauge measurement value.
5. Compare the adjusted gauge measurement value to the Actual Value stored in the applicable low pressure MVB.
Tip:
In some cases, the MVB actual value is shown in hPa instead of bar. For comparison, 1 bar = 1000 hPa; (5000 hPa = 5 bar).
6. If the MVB value deviates more than ?.0 bar from the adjusted gauge measurement value, then the DTC was likely triggered by a faulty G410
low-side fuel pressure sensor. In this case, document the adjusted gauge measurement value and MVB value on the Repair Order and perform the
Sensor replacement procedure below.
Audi Q7 Quattro 254
Sensor replacement procedure
1. Replace the G410 low-side fuel pressure sensor.
2. Clear DTCs and verify that the problem was eliminated.
3. If applicable, run Basic Settings to adapt low-side pressure system.
4. Do not replace the high pressure fuel pump, electrical fuel pump, fuel pump control module or fuel filter unless problem persists and further
diagnosis indicates a malfunction of any of these components.
Audi Q7 Quattro 255
Warranty
Required Parts and Tools
Additional Information
All parts and service references provided in this TSB are subject to change and/or removal. Always check with your Parts Department and service
manuals for the latest information. provided in this TSB are subject to change and/or removal.
Fuel System - MIL ON/Multiple Fuel Pressure DTC's Set
01 MIL on (DTC P310B, P129F, P008B, P129E, P008A, P2540, P0087)
24 09 28
2022132/1
December 18, 2009
Affected Vehicles
Condition
MIL on and one or more of the following DTCs are stored in the ECM data memory:
^ P310B (Low-pressure fuel system regulation, fuel pressure outside tolerance)
^ P129F or P008B (low-pressure fuel system, pressure too high)
Audi Q7 Quattro 253
^ P129E or P008A (low pressure fuel system, pressure too low)
^ P2540 (low pressure fuel system, pressure out of range)
^ P0087 (rail fuel pressure system, pressure too low)
Technical Background
Comparing Measure Value Block 103 with 106 is not an accurate method to diagnose low-side fuel pressure sensor G410.
In order to diagnose G410 accurately, use a mechanical gauge and compare results with the low-side fuel pressure Actual Value in the applicable
Measured Value Block (varies by engine).
Production Solution
Not applicable.
Service
1. Verify the customer did not run out of fuel at the time the DTCs were stored.
Tip:
P310B and/or P129E / P008A may be accompanied by P1250. If so, it is likely the faults occurred due to a low fuel level and not a malfunction of
the G410 Pressure Sensor.
2. Follow indication of GFF for applicable DTCs.
3. To check the low-side fuel pressure sensor G410, measure the fuel pressure with a mechanical gauge using the following method:
a. Start engine and allow to idle for at least one minute.
b. Stop the engine.
c. Keep the ignition on.
d. Measure actual low-side fuel pressure via mechanical gauge (VAG 1318) on the low pressure supply line in the engine compartment (Figure 1).
4. Add 1 bar to the value obtained from the mechanical gauge to calculate the adjusted gauge measurement value.
5. Compare the adjusted gauge measurement value to the Actual Value stored in the applicable low pressure MVB.
Tip:
In some cases, the MVB actual value is shown in hPa instead of bar. For comparison, 1 bar = 1000 hPa; (5000 hPa = 5 bar).
6. If the MVB value deviates more than ?.0 bar from the adjusted gauge measurement value, then the DTC was likely triggered by a faulty G410
low-side fuel pressure sensor. In this case, document the adjusted gauge measurement value and MVB value on the Repair Order and perform the
Sensor replacement procedure below.
Audi Q7 Quattro 254
Sensor replacement procedure
1. Replace the G410 low-side fuel pressure sensor.
2. Clear DTCs and verify that the problem was eliminated.
3. If applicable, run Basic Settings to adapt low-side pressure system.
4. Do not replace the high pressure fuel pump, electrical fuel pump, fuel pump control module or fuel filter unless problem persists and further
diagnosis indicates a malfunction of any of these components.
Audi Q7 Quattro 255
Warranty
Required Parts and Tools
Additional Information
All parts and service references provided in this TSB are subject to change and/or removal. Always check with your Parts Department and service
manuals for the latest information. provided in this TSB are subject to change and/or removal.
