Error 17656: Performance Issues & Troubleshooting

Hello,

My Octavia 1.9 TDI (110 hp, manufactured in 2000, approximately 105,000 km) has had very little power in the lower RPM range for about a week. It only starts to feel almost normal again above 2300 RPM. This problem appeared quite suddenly while driving (around 50 km/h going up a slight incline). I've been to my local mechanic twice. The first time, he only read the error codes and ordered an ASR switch (the ASR indicator was constantly on, and the switch itself broke when trying to turn the ASR function on and off). The second time (when I left the car there for a few hours), he said it might be related to the camshaft timing and that the timing belt may have slipped. He wants me to come back next week to investigate this further.

Meanwhile, I have used VAG-COM to read the error codes, and the following errors were found (using the English shareware version):

Address 01
17656 - Injection Start Regulation: Control Deviation.
P1248 - 35-10 - - - Intermittent

Address 03.
01314 - Engine Control Module.
013 - Check Diagnostic Trouble Code (DTC) Memory - Intermittent.

Then I read out some engine groups, and for the following groups, there were deviations from the target values:



Are these typical values for a slipped timing belt, or could something else be the cause (fuel filter, fuel injection pump, hose connections, etc.)?

The timing belt was replaced about 5,000 km ago by a friend (not a professional mechanic), but everything has been fine since then. And I don't use biodiesel.
It would be great if someone could help me.


Best regards,
Ralph

rhae wrote:

Then I read out some engine groups, and for the following groups, there were deviations from the target value:

Hi Ralph,
The air mass sensor reading suggests a malfunctioning EGR valve (assuming it hasn't been disabled). This could be due to a lack of vacuum pressure, which could also explain the sluggishness at low RPM (the VTG is not closing properly).

Quote:

Are these typical values for a skipped timing belt, or could something else be the cause (fuel filter, fuel injection pump, hose connections, ...)?

If the engine was warm during the log, the early injection timing could be due to a slipped timing belt -> have it checked as soon as possible!
Alternative possibility: a stuck or jammed check valve inside the pump.
Regarding issues with the injection molding machine's pressure regulator (specifically, interruptions), I believe there should be a more specific error message logged.

Hi,

Water ingress in the control unit or at the connectors?
Okay, let's clear all the error codes again, and after checking the timing belt (i.e., verifying the timing), take another drive and see what comes back.

Best regards, Rainer.

Thank you for your quick help. So, when I read the data, the engine was somewhat warm (I let it run for a while to get good readings). And my workshop and I have already cleared the error memory several times, but the entries reappear immediately after the next start .


Best regards,
Ralph