Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: 2.5v6 on 05 July 2019, 21:07:20

Title: Crank sensor wiring diagram
Post by: 2.5v6 on 05 July 2019, 21:07:20
Evening all
Got a slight issue with my car. Stalling at junctions and traffic lights. Checked fault code and was showing crankshaft sensor fault. Replaced sensor and fault code still present/won’t clear. Does anyone have a wiring diagram for the crankshaft sensor circuit so I can confirm if it’s a sensor fault or wiring/ecu fault?
Title: Re: Crank sensor wiring diagram
Post by: Nick W on 05 July 2019, 21:09:44
Try disconnecting the MAF, and see if that helps. It will put the EML on, but that's not a problem.


Reading the codes without the engine running will always return a cranksensor code. But that's for no signal, which you should expect with a stationary engine.
Title: Re: Crank sensor wiring diagram
Post by: zirk on 05 July 2019, 21:52:57
By replacing the sensor did it cure the original fault?, if yes dont worry the Code aill prbablg clear in time.
Title: Re: Crank sensor wiring diagram
Post by: 2.5v6 on 05 July 2019, 22:08:14
She still runs the same without the MAF sensor I need to no what signal/earthing/live that is coming from the Ecu, car stalls at lights and junction/idle I need to rule out the Ecu
Title: Re: Crank sensor wiring diagram
Post by: Doctor Gollum on 05 July 2019, 22:22:21
What crank sensor did you buy?
Title: Re: Crank sensor wiring diagram
Post by: zirk on 06 July 2019, 03:13:30
Never owned a 2.5, but Idle Control Valve ?
Title: Re: Crank sensor wiring diagram
Post by: dave the builder on 06 July 2019, 07:44:52
Never owned a 2.5, but Idle Control Valve ?
that's what i was thinking
they had EGR valves too  :-\
Title: Re: Crank sensor wiring diagram
Post by: 2.5v6 on 06 July 2019, 07:59:47
Crank Sensor is ‘Lemark’ brand, EGR valve has been change with a working old one so has the throttle sensor.
Title: Re: Crank sensor wiring diagram
Post by: biggriffin on 06 July 2019, 09:57:03
Crank Sensor is ‘Lemark’ brand, EGR valve has been change with a working old one so has the throttle sensor.


Mmm. Nice new shiney GM one here.
 https://www.omegaowners.com/forum/index.php?topic=144271.0
Title: Re: Crank sensor wiring diagram
Post by: 2.5v6 on 06 July 2019, 10:19:30
Let me check my numbers!
Title: Re: Crank sensor wiring diagram
Post by: Enceladus on 06 July 2019, 11:24:25
Let me check my numbers!
There are three variants of V6 crank sensor and they are not electrically interchangeable.

The earliest has a connector with square sides. This is GM 90492006 / Opel Kat 62-38-333. The Kat number might be stamped on the head.

Then there are two sensors with oval sides. The first of these is 540Ω. This might be a Delphi part and is GM 90492061 / Opel Kat 62-38-126. This part was apparently only used on 2.5 V6. The Kat number might be stamped on the sensor.

And lastly there is a a 850Ω<>900Ω part. This has a Bosch logo on the sensor. It is GM part 90540743 / Opel Kat 12-34-740. It can also be stamped 9049182 which is a factory only number.. This variant is found on later 2.5&3.0 and all 2.6/3.2. The Bosch part number is 0 261 210 131 and this might be stamped on the head of the sensor from factory. Most V6s have this sensor.

So look carefully at the sensor that came off the car. You want one that matches exactly.
Title: Re: Crank sensor wiring diagram
Post by: STEMO on 06 July 2019, 11:40:09
Let me check my numbers!
There are three variants of V6 crank sensor and they are not electrically interchangeable.

The earliest has a connector with square sides. This is GM 90492006 / Opel Kat 62-38-333. The Kat number might be stamped on the head.

Then there are two sensors with oval sides. The first of these is 540Ω. This might be a Delphi part and is GM 90492061 / Opel Kat 62-38-126. This part was apparently only used on 2.5 V6. The Kat number might be stamped on the sensor.

And lastly there is a a 850Ω<>900Ω part. This has a Bosch logo on the sensor. It is GM part 90540743 / Opel Kat 12-34-740. It can also be stamped 9049182 which is a factory only number.. This variant is found on later 2.5&3.0 and all 2.6/3.2. The Bosch part number is 0 261 210 131 and this might be stamped on the head of the sensor from factory. Most V6s have this sensor.

So look carefully at the sensor that came off the car. You want one that matches exactly.

 :y :y
Title: Re: Crank sensor wiring diagram
Post by: johnnydog on 06 July 2019, 12:26:33

Reading the codes without the engine running will always return a cranksensor code. But that's for no signal, which you should expect with a stationary engine.

That's strange. I have used a friends code reader whenever the EML has come on, and never read the codes with the engine running. It throws up the codes for the suspected issue but never a crank sensor code, except for the occasion many years ago when the crank sensor had actually failed.
Title: Re: Crank sensor wiring diagram
Post by: Enceladus on 06 July 2019, 12:41:13
That's right. On the pre facelift 2.5 & 3.0 V6 you get code '31 - No engine RPM signal' if you read the codes before the engine is started.

If the sensor is properly detected as faulty when the engine is running then you might see '19 - Incorrect RPM signal'. I say might because frequently there isn't any code. However stalling at traffic lights etc. is a classic symptom of a failed/failing crank sensor. That said it could be the idle valve. The idle valve can usually be fixed by cleaning the innards with some carb cleaner.

A stuck EGR probably would throw a fault.
Title: Re: Crank sensor wiring diagram
Post by: Doctor Gollum on 06 July 2019, 15:00:56
Crank Sensor is ‘Lemark’ brand, EGR valve has been change with a working old one so has the throttle sensor.
That's why it doesn't work then... Only* ever buy genuine crank shaft sensors from a genuine Vauxhall dealer that you genuinely have to walk in to. And take your reg and chassis number so that there is zero confusion.

* an acceptable alternative is to buy one from someone who has actually, personally done this ;)
Title: Re: Crank sensor wiring diagram
Post by: biggriffin on 06 July 2019, 15:45:17
Crank Sensor is ‘Lemark’ brand, EGR valve has been change with a working old one so has the throttle sensor.


Mmm. Nice new shiney GM one here.
 https://www.omegaowners.com/forum/index.php?topic=144271.0

This a square plug, early fitment, 2.5/3.0. just look at your plug, oval plugs are either metal body, or plastic body.
Title: Re: Crank sensor wiring diagram
Post by: 2.5v6 on 06 July 2019, 17:11:09
It was the crank sensor after all this time I had a spare one in the garage whacked it on and she’s firing on all cylinders been running on idle for some time not missed a beat lesson learned I’m getting one from dealers that’s for your help all
Title: Re: Crank sensor wiring diagram
Post by: 2.5v6 on 06 July 2019, 17:39:31
Now here’s the thing, when I buy one which one do I go for, the one that came out is oval head but Siemens brand, part number 90 492 061, this is the one I’ve put in off the other engine and also had GM stamped on the part
Title: Re: Crank sensor wiring diagram
Post by: Doctor Gollum on 06 July 2019, 17:59:44
Now here’s the thing, when I buy one which one do I go for, the one that came out is oval head but Siemens brand, part number 90 492 061, this is the one I’ve put in off the other engine and also had GM stamped on the part
You buy the one that the dealer matches to the chassis number ::)

Also have a read of this...

http://www.omegaowners.com/forum/index.php?topic=96562.0 :y