p0191 fault code [Resolved]

[Tuneserv]

How do I find out about the remedy's people have found for the 132 kw t6 vw kombi transporter that has just developed a p0191 fault code . Rail pressure sensor range performance . Have replaced the sensor but the problem still persists . Clear the fault and you can drive 160 km no problem . Switch off and leave to stand Turn the key on and the code is back before the engine even runs . ? Anyone had this problem ???

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[n10n]

Check out thread [T6_measured] Monitoring DPF regeneration, DPF condition, EGR operation - there were other symptoms and eventually p0191 fault. Change of rail pressure sensor improved the situation a lot although I think the jury is still out if the sensor was the sole fault.

 

[Jeff@tuneserv]

Thanks will try forced regen . Doesn't make sense as the fault is there before it even starts

 

[Jeff@tuneserv]

Problem solved ! On further investigation and while working the check engine light went out by itself and never came on again. So I decided to check the pins on the ecu and check for corrosion. While checking I found that this vehicle had had a Unichip fitted at some stage. Maybe because the guy has added every conceivable accessory and vehicle just to heavy The Unichip is connected into the main engine harness. It requires ...Power ,earth,tps,fuel in. ie.rail pressure and crank shaft signal. There appears to be a bad connection on the rail pressure wire . With the unichip removed and the wires returned to standard . The problem has gone. I also noticed black smoke on acceleration meaning Unichip fueling values in the map were excessive. The EGTS would have been to high , so good thing it is out

 

[ebiii]

Problem solved ! On further investigation and while working the check engine light went out by itself and never came on again. So I decided to check the pins on the ecu and check for corrosion. While checking I found that this vehicle had had a Unichip fitted at some stage. Maybe because the guy has added every conceivable accessory and vehicle just to heavy The Unichip is connected into the main engine harness. It requires ...Power ,earth,tps,fuel in. ie.rail pressure and crank shaft signal. There appears to be a bad connection on the rail pressure wire . With the unichip removed and the wires returned to standard . The problem has gone. I also noticed black smoke on acceleration meaning Unichip fueling values in the map were excessive. The EGTS would have been to high , so good thing it is out

Oh I think I have the same problem ! Had p0191, sensor replaced. The problem cale back after 3 months ...
Where was the unichip connected ?
And have you changed anything in the ECU afterwards ?

Because in my case I know the previous owner had a chip and then removed it. There is also a device to repel rodents. I suspect wires are going bad..

 

[Jeff@tuneserv]

Oh I think I have the same problem ! Had p0191, sensor replaced. The problem cale back after 3 months ...
Where was the unichip connected ?
And have you changed anything in the ECU afterwards ?

Because in my case I know the previous owner had a chip and then removed it. There is also a device to repel rodents. I suspect wires are going bad..

Hi you have to look in the ecu area and make sure there are no performance enhancement gadgets attached to the loom.
Thanks Jeff

 

[ebiii]

Oh I think I have the same problem ! Had p0191, sensor replaced. The problem cale back after 3 months ...
Where is the unichip connected ?

Hi you have to look in the ecu area and make sure there are no performance enhancement gadgets attached to the loom.
Thanks Jeff

Thanks ! I removed it. For now no intermittent P0191, we'll see over the next few days.

 

[ebiii]

P0191 hasn't showed yet many thanks for your insight