The following codes were present in the ecu
0403 EGR control circuit
0100 air mass sensor signal to low
0243 pressure converter boost pressure control
When viewing live data the boost pressure appears ok until approx 2krpm at which point it fails to increase further.
There are no boost leaks, the turbo has been replaced, the vac circuit is holding pressure, the boost control pressure transducer is functioning correctly and is receiving the correct voltages from the wiring harness. the maf sensor is ok. the exhaust is not blocked.
does anyone have any suggestions? we have a Bosch kts570 scanner at our disposal if anyone has any ideas on what to investigate next.
Edited by Dynamic Dave on 12/08/2008 at 19:47
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P0243 often seems to turn up with an EGR fault. It's possibly the boost leaking away to the exhaust through a stuck-open EGR valve - that flags low-airflow codes too.
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Sorry, I forgot to mention that we also blanked off the egr at the manifold.
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So do these codes recur after clearing and when/how long do they take?
How much disparity between target boost and actual boost do you get? Tried it with no air filter?
Has the boost hose split down below the battery.
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These codes were present in the ecu when we first saw the vehicle, although the engine management light was not lit, the only symptom was the lack of power through the whole rev range, first off we blanked the EGR to no avail, the egr code did not re apear but the boost code did a short time later, we removed and thouroughly inspected all boost hoses plus the front mounted intercooler which we pressure tested, that was all fine.
We then borrowed another 406 hdi 110, although this was a phase 2 (99) and the problem car is a late phase 1 (99) factory fitted with the hdi 110 engine. The second car ran well and made a good amount of power, from this car we tried swapping the boost control pressure transducer, this made no difference, we also checked the voltages supplied to the transducer, these were ok. next we looked at the live data from the working car while out on the road and compared it against live data from the problem car, as we suspected boost increase was comparible on both cars upto 2-2.5krpm after which it leveled off on the problem car.
The air filter is only a month or two old as the car was recently serviced.
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neil
Does the problem pre-date the air filter? How/when did it start? There is no significant difference between an RHZ in a late D8 and one in a D9 model.
How did you check the MAF; is it a genuine dealer-supplied one? Doesn't the KTS show a target boost to compare with the actual?
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the problem pre dates the air filter change, we swapped the maf for a known working maf in a different RHZ vehicle, this had no effect on either vehicle. I will look at some live data in the morning and compare what the kts expects although I have a feeling it only gives idle figures. I might be able to borrow another working RHZ 406 to compare against anyway if I'm lucky. I'm waiting on a mityvac to check the wastegate actuator and the rest of the vac system for the correct readings to rule that out, only trouble is we can't get one for a few days. The kts also has a scope if there is anything worth scoping?
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