Fuel System - MIL ON/Fuel Pressure DTC's Set
24 08 582017356/2
November 19, 2008. Supersedes Technical Service Bulletin Group 24 number 08-11 dated March 3, 2008 for reasons listed below.
Vehicle Information
01 MIL on (DTC P310B, P129F, P2293, P0087)
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 (low-pressure fuel system, pressure too high)
- P2293 (Fuel pressure regulator 2, performance)
- P0087 (Rail fuel pressure too low)
Technical Background
Due to fuel intrusion into the low-pressure system fuel pressure sensor (G410), a false signal may be sent to the controller resulting in a reading that is out of tolerance.
Production Solution
Improvements to G410 fuel pressure sensor.
Service
1. Follow the indication of GFF for applicable DTCs.
2. Measure the fuel pressure using one of the following methods:
Alternative 1
1. Start engine and allow it to idle.
2. Disconnect the fuel metering valve electrical connector (N276 or N290) on the high pressure fuel pump.
3. Compare fuel pressure values from MVB 103 field 1 and MVB 106 field 1.
4. If the MVB 103 value deviates more than +/- 0.5 bar from the MVB 106 measurement, then the DTC was likely triggered by a faulty G410 low-side fuel pressure sensor. In this case, perform the Sensor Replacement Procedure below.
Alternative 2
1. Start engine and allow to idle for at least one minute.
2. Stop the engine.
3. Keep the ignition on.
Figure 1:
4. Measure actual low-side fuel pressure via mechanical gauge (VAG 1318) on the low pressure supply line in the engine compartment (Figure 1).
5. Add 1 bar to the value obtained from the mechanical gauge to calculate the adjusted gauge measurement.
6. Compare the adjusted gauge measurement to the value stored in MVB 103 field 1.
Tip:
The MVB 103 field 1 value should be approximately 1 bar above the mechanical gauge reading. This is a normal condition and does not indicate a faulty sensor.
7. If the MVB 103 field 1 value deviates more than +/- |1.0 bar from the adjusted gauge measurement, then the DTC was likely triggered by a faulty G410 low-side fuel pressure sensor. In this case, perform the Sensor Replacement Procedure below.
Sensor replacement procedure
Figure 2:
1. Replace the G410 low-side fuel pressure sensor.
2. Clear DTCs and verify that the problem was eliminated.
3. Run Basic Settings 103 to adapt 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 on any of these components.
Warranty
When procedure applies to vehicles under warranty, use the following:
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.