940 not-quite-OBD2

[rogerthechorister]

The article about building a reader has lost its attached thumbnail, here http://www.volvoforums.org.uk/showthread.php?t=61562

The posts for an 850 may or may not be the same but is a little unclear to me, here http://www.volvoforums.org.uk/showthread.php?t=46943

And has anyone got a list of the fault codes please?

[Husqyman]

This help??

and this as well http://www.volvoclub.org.uk/faq/EngineOBDCodes.html

[rogerthechorister]

Thank you for that. At a first glance the FAQ seems to say that VOlvo went from the box (or boxes) on the suspension turret directly to needing a computerised code reader for full OBD2 - and I know that that is not right at least for UK cars where quite a lot of 940s had what looked like an OBD2 socket in the central cubby but which did not produce standard OBD2 codes. I'll read it again.

Have you any idea when the "revised" codes apply from?

And has anybody got the circuit diagram/construction details to make a not-quite-OBD2 reader?

[rogerthechorister]

I found another thread withthe same pictures.

I think some mod or other might want to link teh standard article to this thread - http://www.volvoforums.org.uk/showthread.php?t=98903

And put the pictures somewhere safe!

[CTCNetwork]

Hi,

Ahhh... The attachments... Tell me about it..
Those are on photobucket..

Des. . .

[Husqyman]

Not sure about revised codes, I think they went from under bonnet to in the armrest pocket (OBD alike socket) around 94-95

[rogerthechorister]

Sensors under the manifold correctly attached.
Cam timing correct.
Injectors and seals OK.
That silly electrical lead at the back of the engine (cam position sensor?) OK.
3 metres of the little turbo hoses (including turboplus hoses) OK
Various vacuum hoses off the inlet manifold OK
Throttle position sensor OK
Lambda sensor was horrible but has been changed and was not a cure.
Crankcase breather hose is a twin-layer hose (a layer of plastic and one of rubber) and one layer is iffy but surely one layer remaining will suffice and anyway it wouldn't cause the manifested fault.
Plugs checked and OK.
HT leads checked and OK.

I'm going to buy a spray can of AMM cleaner (if it foxes the AMM well a pattern AMM is not that dear).

Garage knows a bloke wot has a load of 90s adaptors for OBD (and with any luck he will know if he can't read the VOlvo not-quite-OBD) and will ask him to try to read the socket.

Failing which - and failing any other ideas - I'm going to build the Volvo code reader.

Incidentally, the fault is not significantly different from when I drove the car into the garage, so whatever it is is something that would NOT normally be changed when doing head gasket (and clutch).

[rogerthechorister]

As per title!

[rogerthechorister]

The local OBD2 wizard has retired defeated by the cunning of the Volvo system. All he could read was about the airbag.

I have ordered the parts to make a Volvo Code reader. Some of the bits elsewhere listed here are not consistent from thread to thread, so when they get here and I make them fit together I will put up a corrected list.

In particular the Pang OBD2 connector previously suggested is out of stock. There is a different one with a right angle entry that I have ordered.

Maplins no longer do a 1.8k resistor - funny that I'm sure it's a preferred value - so I've ordered a 1.5k one. I am not sure if it is necessary - one set of parts includes it, the other not, and text suggests it can be omitted. Watch this space. We'll try first with the 1.5k in circuit to be on the safe side and only remove it if there is no joy with it in.

One list suggests a 2-way toggle switch - fine and dandy if you only want to read two sets of codes - so I ahve got a rotary switch. The only single pole rotary switch that Maplins do is now 12 way so I expect some VERY fiddly wiring.

[lnparry]

Please do share how you get on. I am pretty hopeless with electrical stuff but now I have my first Volvo with lots of electrical gizmos I will probably have to take the plunge to.
Good luck,
LeeP