Amarok diesel problem

[andrew55]

Currently my rok is off the road for the past 3 weeks, the coily warning light came on & it went into limp home mode with very little boost, I managed to get it it to the mechanic however the engine check light had also come on. the scan tool came back with 4 faults P0236 turbo boost sensor, P0651 Sensor ref voltage, P1440 & P0403 EGR Ref & voltage codes. the earths at various points were cleaned & reattached. The EGR Cooler was also clogged, this was cleaned & reassembled. The rok was driven for 30kms all was fine. Hey presto drove out of the mechanics & the coily light came on & lost boost, promptly turned around & left it at the mechanics once again. Also have bench tested the turbo actuator & this was working correctly. This part had actually failed on my tdi tiggy at 97K. the rok has only done 75k, I bought it with 65k on the clock.
anyone got any ideas????

[Darkhorse Developments]

Ive had 2 like this and made up a new wiring loom between the turbo pressure sensor and the ecu. Cured both. (Might not cure yours!) Made up a 4 wire loom with new pins and either end and worked.

[andrew55]

thanx for the heads up darkhorse, hopefully will get a result soon & post.

[edi25]

if it's under warranty, vw will probably replace your turbos (mine were replaced at about 30000km from the same issue), as it's the whole assembly they replace. The fault was probably only the boost solenoid valve. I could switch the car off and back on, have full power again until the same conditions were met, then it would go back into limp mode with the flashing glow plug light. In my instance it happened at 100km/hr with cruise control on.

[andrew55]

at last a solution, the egr valve soleniod had a malfunction i.e. stuffed. solution was to replace egr valve assembly, cooler & assoc gaskets. total bill at VW dealership was a bit over $1600, including parts component of about $640. This was the 2nd one that the dealership had seen with the same problem. I must say great service even washed & cleaned the car inside & out.
It leads me to think a 3inch ss exhaust, egr blankoff & ecu reprogram may be the ultimate solution.

[andrew55]

50 kms max & back into limp home mode with coily light flashing with reduced boost; back to dealership, await with baited breath, not!!!

[andrew55]

picked up rok today, they reprogrammed the parameters in the ecu for the new egr valve, drove it for about 40kms, no problem, soon as I drove home after 20kmsl back into limp home. the new fault is low boost which I think is a furphy as it's the ecu trying to protect the engine from damagei!!!

[andrew55]

Picked up the rok twice this week, drove less then 20kms and coily light back on & back to the dealership. I think that they are thinking it could be an issue with the turbo or turbos. Been at dealership for 3 weeks as of yesterday. On Tuesday they checked the boost controller & it was recalibrated to factory specs, still no joy. edi25 may be right, unfortunately in my case no warranty. I have emailed VW Australia to see if they will offer any remedy!

[buzuki]

Id be looking at what darkhorse said.

[andrew55]

hi buzuki,
they checked that part of the wiring loom, all connections etc, could not find or generate a fault. It seems to be occurring at 2600-3000 rpm. does not generate a specific fault code.