2004 Astra 1.6 p0110

Hi All, I have a 2004 Vauxhall Astra z16xep with code P0110, the air intake temp' in freeze frame says -40c, the spanner light is on followed by the engine light, the car then loses power, the thing is that there is 5volt readings on both connector wires with key on engine off? I thought one wire should be 0 volts?
I can't find much info on google and hope someone might be able to point me in the right direction. many thanks for any help.

I think you are, already, looking in the right direction. Disconnect the connector and check the harness side. Do you still have 5 volts on both wires? If so, your ground wire is shorted to 5 volts. If not, do you have a good ground on the wire that does NOT have 5 volts?

Thank you for your reply, yes unpluged there is still 5v on both wires. Would you expect this to be a loom or ecu fault? Or could I try running a new ground wire in? Many thanks.

Both wires on the IAT show 5V KOEO and unplugged? :blink: Weird!

Is the P0110 your only code? For giggles, I'd be tempted to test some other 5V sensors under the hood, just to see if any of their grounds show 5V, too. 5V reference sensors commonly share grounds, so if there's an ECU problem, I'd expect other sensors to show the same thing.

I'd hesistate to run a new ground? :huh: 'Cause you could end up shorting the 5V reference to ground and pulling down the computer with it. Most PCM's will survive that, but you'd rather not do that if you don't have to.

A wiring diagram would be awesome, too. They don't sell Astra in the US, otherwise I'd find one.

Yes P0110 is the only code. I retested today on a cold engine left over night and found it had a GOOD ground with 0 volts, when I warmed it up it was back to NO ground with the 5 volts????

WTF? :huh: I think we definitely need a wiring diagram at this point.

At Z16XEP engine the Intake air temp sensor got 2 wires ...

The one is brown and is shared between cam sensor, IAT and throttle body ....

and the other is brown-black (that is the signal)

The brown wire is the ground and it comes str8 from the ECU i think ...

If that ground was broken shouldn't you have other fault codes also ???

hmmm ... that needs little thinking ... hmmm :huh:

BTW If his Astra is the H (2004 - 2009) model, in USA, GM was selling it as Saturn Astra i think ... or something like that ...

Ok so this is what I have this morning on COLD engine..
KOEO IAT reads 26c..
Pulled the connector off and jumped it IAT READS 149C..
Unplugged no jumper -40c..
KOEO unplugged there is 5 volt ref
0 volt grd
KOEO Plugged in ref drops to 2.5 volts??
0 volt ground..
I thought it might be worth concentrating with cold values first? As the engine hot values are twisting my brain.
Thanks for all your input..

NEW CODE manufacturer specific P1405
engine fully up to temp, engine died and stalled, this was at idle.
Restarted, revs stuck at 1500rpm NO throttle.

Live data seems to show that the IAT is working ok??????

Can this all be tied together?

Hello, I have info for european version but I think is not much diference...only on wires colors! For the P0110 with KOEO unplugged;
-br/black(US) measure voltage to ground, must has more then 4.8volts;
-black measure voltage to ground, must has less then 0.3volts;
-jumpe a fuse wire between them and you must see on data pid less then 0.3volts;
-if you have more look wire problem or ECM!
Note that with engine hot the welding points on ECM can became "lose"!

Are you shore is P1045? I have only P1405!

Thank you, Yes I am thinking computer falt to be honest, just want to make sure, the readings just seem to be all over the place, makes me think the computer is being confused internally maybe??

Sorry yes it;s P1405

During measurements, tapp on ECM and see if values(voltage) change!