[classiccarman]

Anyone know what causes the "High Turbo Boost" fault code to flag up? This is following on from a previous post on fitting a Drake Tuning box to my engine. The fault occurs with the box fitted or not so its not the tuning box causing it. I have cleared the code using OPCOM each time but re-occurs if you accelerate enthusiastically kicking the turbo in. Accelerating gently does not cause the fault to flag up but who wants to drive like a Granny every where?

 

[djgregory]

will be the tuning box causing it i reckon

 

[evilfish5000]

It's the box you can clear the fault code fine but soon as it goes back on it sets it off again. Get a proper remap not a cheap nasty box.

 

[classiccarman]

What causes High Boost fault on 1.7cdti Denso ECU ?

It's not the tuning box as the car had the fault from when I bought it 3 years ago.
I've only just recently fitted the Drake Tuning box and it works great when the fault dosen't trip the dreaded Limp Mode.
I took it to a Vaux main dealer who updated the ECU software to make the EGR valve work harder which improved it quite a bit. It only trips occasionally now. Makes you wonder if it was the reason they switched to Bosch ECU's on later models like fitted on the Astra.
Anybody else with the 1.7cdti engine experiencing the same problem?
I've heard it is very difficult to get remapping right on the Denso ECU so I don't want to waster further money on a re-map.
Does any one think a bigger intercooler would improve things?
I'll just have to get a real Nurburgring Corsa when they become a bit cheaper !

 

[ianofbhills]

Not sure if the 1.7 turbo has a wastegate or is a variable nozzle turbo but high boost pressure means your turbo is overboosting due to the wastegate or vnt being sticky. You can try cleaning it and freeing it off with some penetrating oil and manually operating it, this is a very comon problem on the 1.3 and yours sounds like it is doing it too. defintately try that before replacing the turbo.


Also worth trying a new boost pressure sensor in case the signal from that is corrupt, they are only about £20 and easy to change.

 

[evilfish5000]

It's not difficult to map a 125ps. All they do is take the ecu out of the car then it can be mapped. It's easy to find threads saying you can't map it. They have been proven wrong there is a couple of guys with 125ps remaps and my 130 ps is mapped. You can safely map a 125ps to 160 bhp.

 

[classiccarman]

It has a variable nozzle turbo. I will try your suggestions Ian, as it seems the cheapest :smile: I will look further into re-mapping, evilfish, and weigh up if it is worth me going that route.
I have had the car 3 years now (not exactly trouble free, the spanner light has been on more than off), and fancy a change like the Astra VXR that even Clarkson likes.:thumbs: Not any about second hand though.
Another problem I have on the engine is a broken glowplug that refuses to unscrew which Vaux says is a cylinder head off job:yikes:. Only brings on the fault light on cold mornings like we are having now. Might fool the glowplug controller by sticking a 0.5 ohm power resistor across the stubborn glowplug.:shock:

 

[DJ_Ben_DJB]

I had a similar problem with a 57 plate Corsa Design 1.7CDTI, turned out to be that it had a small split in the vacuum hose where it connects to the actuator, bought replacement hose (£5 ebay job) solved the problem.