Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: JamesV6CDX on 10 September 2008, 13:59:23

Title: Fault code 38 still
Post by: JamesV6CDX on 10 September 2008, 13:59:23
I was getting code 38 - low voltage for lambda one

I swapped the sensors around and cleared the codes, but the code 38 has come back, so it's not the sensors.

Please can someone help  :'(

I suspect a wiring problem? But electickery and me don't mix too well  :'(
Title: Re: Fault code 38 still
Post by: cem_devecioglu on 10 September 2008, 14:18:31
how abouts fuel consumption compared to before (healthy state) ?
Title: Re: Fault code 38 still
Post by: JamesV6CDX on 10 September 2008, 14:31:36
Quote
how abouts fuel consumption compared to before (healthy state) ?

The same.... economy is actually reasonable...
Title: Re: Fault code 38 still
Post by: cem_devecioglu on 10 September 2008, 14:37:54
if lambda sensors become fubar , fuel economy definitely changes :-/

mine did..

James I estimate you have tech II similiar devices cant you monitor their voltages ?
Title: Re: Fault code 38 still
Post by: JamesV6CDX on 10 September 2008, 14:44:00
Quote
if lambda sensors become fubar , fuel economy definitely changes :-/

mine did..

James I estimate you have tech II similiar devices cant you monitor their voltages ?

I am able to read and reset codes, but not look at live data :(
I have asked TB if we can plug his Tech2 in relatively soon - hopefully the live data may give an idication as to what's up.


Title: Re: Fault code 38 still
Post by: cem_devecioglu on 10 September 2008, 14:49:25
Quote
Quote
if lambda sensors become fubar , fuel economy definitely changes :-/

mine did..

James I estimate you have tech II similiar devices cant you monitor their voltages ?

I am able to read and reset codes, but not look at live data :(
I have asked TB if we can plug his Tech2 in relatively soon - hopefully the live data may give an idication as to what's up.


yep..
Title: Re: Fault code 38 still
Post by: Marks DTM Calib on 10 September 2008, 15:58:55
Why narrow it to wiring when it could be an engine fault!

Anyway, here is the checking procedure:

Conditions required to raise code:

1.) Coolant temperature is greater than 70 °C (158 °F);
2.) Condition 1.) fulfilled for 3 min;
3.) Engine load signal is greater than 1.7 ms;
4.) After conditions 1.) to 3.) are fulfilled, waiting period of 5.1 s elapsed;
5.) Following trouble code not recognised: 73, 74;

Replacement value:

450 mV (oxygen sensor closed loop control is disabled)

Concerned terminals - 28 and 10

So what the above is saying is that the code is raised only once the engine is hot (so it not on the warm up cycle) and the engine is loaded (and not initial idling!) plus, the MAF sensor is not nackered.

My next steps would be to measure at the O2 sensor end to check the heater voltage is there......and work from this

But, dont rule out an injector fault or similar!
Title: Re: Fault code 38 still
Post by: JamesV6CDX on 10 September 2008, 16:07:30
Thanks mark

Interesting what you say - as it does only log the code once it's up to temp :y
Title: Re: Fault code 38 still
Post by: JamesV6CDX on 10 September 2008, 16:09:05
You say terminals 28 and 10 - do you mean on the ECU plug?

Title: Re: Fault code 38 still
Post by: Marks DTM Calib on 10 September 2008, 16:15:04
Quote
You say terminals 28 and 10 - do you mean on the ECU plug?


Yes

You should be able to measure the presence of 12V across two terminals at the lambda also which are the heater feeds, the third connection is the lambda signal and the 0V is via the exhaust
Title: Re: Fault code 38 still
Post by: JamesV6CDX on 10 September 2008, 16:21:39
Do you happen to know what colours the heater feeds are on the sensor, Mark?
Title: Re: Fault code 38 still
Post by: Marks DTM Calib on 10 September 2008, 16:25:03
Quote
Do you happen to know what colours the heater feeds are on the sensor, Mark?

From memory

0V - Brown (pin A?) and 12V - Red/Black (Pin B?)
Title: Re: Fault code 38 still
Post by: JamesV6CDX on 10 September 2008, 16:27:25
Does it matter if I measure for 12v across the heater when the car is cold or hot?
Title: Re: Fault code 38 still
Post by: philhoward on 10 September 2008, 20:14:24
I'd guess not - heater voltage should be applied from startup.

Correct me if i'm wrong - but itsn't the heater only used DURING warmup?  After its warm, there should be no need for the heater, so surely its the actual Lambda voltage you're looking for?
Title: Re: Fault code 38 still
Post by: Kevin Wood on 11 September 2008, 10:12:35
IIRC, the heater is driven from the fuel pump relay so it should be powered whenever the engine is running.

I'd check the wiring to that Lambda carefully, as I recall it being a bit loose when we were under there. Maybe it has caught on the exhaust.

If the heater supply checks out OK have a look at the voltages at the ECU input for the 2 sensors - or view the live data and see what's happening.

Kevin
Title: Re: Fault code 38 still
Post by: JamesV6CDX on 11 September 2008, 10:35:39
Quote
IIRC, the heater is driven from the fuel pump relay so it should be powered whenever the engine is running.

I'd check the wiring to that Lambda carefully, as I recall it being a bit loose when we were under there. Maybe it has caught on the exhaust.

If the heater supply checks out OK have a look at the voltages at the ECU input for the 2 sensors - or view the live data and see what's happening.

Kevin

Do you have a data reader, Kev?

Just wondering how easy it would be to swing by on the way home from WIM tomorrow, if you're around ::)
Title: Re: Fault code 38 still
Post by: Kevin Wood on 11 September 2008, 11:39:58
I have a live data reader but it'll only do OBDII cars so probably not going to work on yours. Feel free to drop by, though. We could have a go with a multimeter and try to figure things out. And you could pick up the things you forgot last time you visited. ::)

 ;)

Kevin

Title: Re: Fault code 38 still
Post by: TheBoy on 11 September 2008, 19:06:28
Quote
I have a live data reader but it'll only do OBDII cars so probably not going to work on yours. Feel free to drop by, though. We could have a go with a multimeter and try to figure things out. And you could pick up the things you forgot last time you visited. ::)

 ;)

Kevin

might be able to loan you a tech2, when i get the bugger working again....      .....2 conditions attached ;)

[/list]
Title: Re: Fault code 38 still
Post by: JamesV6CDX on 11 September 2008, 19:32:39
Quote
Quote
I have a live data reader but it'll only do OBDII cars so probably not going to work on yours. Feel free to drop by, though. We could have a go with a multimeter and try to figure things out. And you could pick up the things you forgot last time you visited. ::)

 ;)

Kevin

might be able to loan you a tech2, when i get the bugger working again....      .....2 conditions attached ;)

  • 1 you already know about
  • 1 you don't!
[/list]

Are you just buying every single Tech2 in the world, so you can control the market? :D