Control Difference Intermittent: Troubleshooting Guide

Today, I connected my diagnostic interface to the 1998 A4 1.9 TDI quattro using VAG-COM, and I was able to read the following error message from the diagnostic memory:

Address 01: Engine.
Controller: 038 906 018P
Component: 1.9L R4 EDC 00SG 1623
Coding: 00003
Shop # WSC 06325
1 Fault Found:
00550 - Start of Injection Regulation.
17 - 10 - Control Difference - Intermittent

What does this error mean? Can anyone help me?

Best regards,

Hannes.

00550 Injection start control, setpoint difference.


Possible cause of error: -> Injection start not functioning correctly. -> Possible consequences: -> Lack of power at higher speeds and/or difficulty starting the engine. -> Troubleshooting: -> Check and adjust the injection timing.


Possible cause of error: -> Injection pump adjustment range blocked (dirt, debris). Possible consequences: -> Reduced power at higher engine speeds. Troubleshooting: -> Check the fuel injection system.

Possible cause of error: -> Fuel supply interrupted: fuel tank empty, fuel line or filter clogged, system drawing air. Possible consequences: -> Possibly error code 00542: implausible signal from needle lift sensor. Troubleshooting: -> Check the fuel system.

Possible cause of error: -> Engine was stalled (within the last 50 starts).
Troubleshooting: -> Clear the error memory and continue to monitor the vehicle.

Possible cause of error: -> Wiring fault to the injection start valve (N108) - Possible consequences: Engine misfires at idle because the injection start timing is constantly set to 'early.' Possibly multiple errors are stored. Troubleshooting: -> Check the N108 valve, -> Check the fuse.

Possible cause of error: -> N108 injection timing valve worn out. Possible consequences: -> Inability to maintain a consistent injection timing at the 'basic setting' (display field 2 fluctuates more than 10 units) - uneven engine running, lack of power. Troubleshooting: -> Replace the N108 injection timing valve.

Hi Hannes,

Injection start may occasionally be difficult to regulate.

Please search for '*550'.

Best regards, Rainer.