VECTRA CDTI 150 ECU FAULT CODE

[Gav44]

Hi,
I am having an ambient air temp fault code that shows on Opcom. The car does seem to be running a bit rough.

Its hard code that Opcom wont clear in ecu. I changed the MAF but the code still there although there is a problem with the outside temp sensor that gives a different code.

Could the two faults be linked?

[MJRVR]

Why not tell the codes?

[Gav44]

Why not tell the codes?

Sorry codes are:

ECM P0070-71 AMBIENT AIR TEMP SENSOR MALFUCTION

BCM B0173-05 OUTSIDE TEMP SENSOR CIRCUIT OPEN OR HIGH VOLTAGE

The car has been losing fuel rail pressure intermittently and has had new HP Pump fitted due to the engine cutting out.

Im now thinking it may be electrical problem with short circuit causing dropping fuel pressure

[Dunker]

Wouldnt have thought ambient air temp would make engine run rough. Id be checking injectors assuming the filter, spill pipes (& if its got one the tank pump) etc. have been checked.

[MJRVR]

Sorry codes are:

ECM P0070-71 AMBIENT AIR TEMP SENSOR MALFUCTION

BCM B0173-05 OUTSIDE TEMP SENSOR CIRCUIT OPEN OR HIGH VOLTAGE

The car has been losing fuel rail pressure intermittently and has had new HP Pump fitted due to the engine cutting out.

Im now thinking it may be electrical problem with short circuit causing dropping fuel pressure

What's the Maaf reading at idle?

[Gav44]

My laptops not working without being connected to mains extension . But I think 30 or 40 rings a bell and there is usually a slight variation of 10 between desired and actual on Opcom.

The original maf readings are the same as the replacement. The ambient temp reading is on the same screen as Maf on Opcom and reads 20c and does not change.

[Gav44]

Wouldnt have thought ambient air temp would make engine run rough. Id be checking injectors assuming the filter, spill pipes (& if its got one the tank pump) etc. have been checked.

What I mean is limp mode when rail pressure problems start.
Ive got a new fuel filter housing coming tomorrw and have good pressure coming from intank pump. No air bubles I have bypassed filter housing to test with clear tubing.
Also did leak back test and although no. 2 and 4 injectors are leaking back more than other two the car starts first time and runs ok before limp home starts.

[hino18]

Gav44 ,have you checked the large multi-plug behind the rocker cover , had one with similar problems and it was the connections on the multi-plug ,ambient air might just be a thrower().

[Gav44]

Gav44 ,have you checked the large multi-plug behind the rocker cover , had one with similar problems and it was the connections on the multi-plug ,ambient air might just be a thrower().

Hi pal, I have did all that, ABS plug to.
I dont really know where or what the ambient air temp sensor is. But its definately being monitored by the ECU and I think it has something to do with fueling/mixture as my MPG has not been good when problems started.
Looks like the front bumper will have to come off to check all the wiring and ECU

[clusters]

The ambient air temp sensor is for the outside air as a rule, usually behind the front grille. If there is a connector anywhere up front that the temp sensor connects to, check for corrosion.

Disclaimer: I have never seen one of these cars, just general knowledge.

[autoden]

If you changed the MAF i hope it was genuine GM. These do not work well with aftermarket cheap rubbish.

[Gav44]

If you changed the MAF i hope it was genuine GM. These do not work well with aftermarket cheap rubbish.

Yes genuine Bosch replacement. Not new but exact same readings as original so I think both are ok

[Bllinda]

Write vin PM

[Gav44]

Just a quick update.
I installed a new GM fuel filter housing and filter and the car is not stalling after a run. So it looks promising but will get a better test tomorrow an get it connected to Opcom.

The spanner light is still on due to the Air Temp Fault but if I manage to get it sorted I will post back.

Its needing a fair bit of work to get it right and all the usual faults like swirl flaps, dpf and egr.

[Bllinda]

I would do it as soon as possible.

Just a quick update.
I installed a new GM fuel filter housing and filter and the car is not stalling after a run. So it looks promising but will get a better test tomorrow an get it connected to Opcom.

The spanner light is still on due to the Air Temp Fault but if I manage to get it sorted I will post back.

Its needing a fair bit of work to get it right and all the usual faults like swirl flaps, dpf and egr.

I did not find tis2000 of this error z19dt, dth, dtl, z20xx.
ECM P0070-71 AMBIENT AIR TEMP SENSOR MALFUCTION