Throttle Body problems? Fault Code 1230

[pompey]

Sorry folks, this is a bit of a saga with my 9-5 Aero (2.3l petrol 2000 X reg)...

About a year ago my car cut out 1 minute after starting my journey from home to the shops and it wouldn't restart. The Green Flag man turned up, read the fault code of 1230, reset it (after checking a few other things) and the car was fine again right up until a few weeks ago when it cut out again on my way to work about 2 miles down the road and wouldn't restart. Luckily it was the same Green Flag man who turned up which reminded me about what had happened last year and I told him it was pretty much the same thing that had happened this time. He reset the fault codes and the car seemed good again - got me to and from work that day.

The following day it cut out almost straight after starting it up so another call to Green Flag and the same guy turns up. This time he's phoned a friend on his way to me to ask them about fault code 1230 and, upon said friend's suggestion, he cleaned the throttle body but then, whilst putting it back together, he noticed a 1 way valve in between 2 pieces of pipe had split so we thought he'd found the true cause of the issues. We replaced it and everything seemed OK until yesterday when the car again cut out on the way to work in virtually the same place but I could actually restart it so Green Flag came to my work to fix it.

This time there was the same 1230 codes but he (different guy) found another small pipe had perished at the end and fallen off so he reconnected it. We took it out for a spin and it felt OK but occassionally a little stuttery at times and the revs seemed to drop off super quick when I eased off the throttle. I was testing it properly and giving it some guts and the Green Flag guy said "Christ, it ain't slow is it" so I was thinking all was well finally!

Anyway, when I came to leave work the car started and ran fine but the engine warning light came on and stayed on. When I got home I disconnected the battery to clear the fault code and then took it for a drive. It was fine this time but when I parked up at MacDonald's and then restarted the car to head home the engine warning light came back on. There doesn't seem to be any reduced power and the turbo gauge still creeps up to the end of the orange zone when giving it the full beans.

I've read that this is to do with the throttle body but I was hoping that, because almost every time the car had the fault there was a problem with one pipe or another, it might not actually be the TB. Any ides? Should I see if I can pick up a 2nd hand one and replace it myslef or isn't it that straight forward?

[sgould]

You have a misread in the position sensors.

There are two sensors.  One connected to the throttle cable.  The other connected to the throttle butterfly.

When you put your foot on the pedal the first sensor (a potentiometer) rotates and the resistance changes.  The ECU read the position and moves the throttle butterfly to match.  The potentiometer attached to it turns in the opposite direction.  The two potentiometers are wired in series, as one increases resistance, the other decreases. The total resistance of the two together should stay the same.  if it isn't the engine light comes on and the throttle body goes into limp mode.

There is a software upgrade to some cars made 2000 and before.  Has your car got the latest version?

Also the resistance reading can be affected by damaged wires and solder joints under the plastic cover of the throttle body.

A proper Saab Tech2 analysis could pin it all down better.

It could also be the Crankshaft Position Sensor (CPS).  My 1998 car had the problem of cutting out immediately after driving off.  It also failed when driving quickly around roundabouts.  I thought my thigh was hitting the key and turning the engine off, but it wasn't.  A new CPS fixed it.

Attached is some bits from the Saab workshop manual.

[pompey]

Thanks for yet another detailed response, sgould. It's much appreciated. You seem to be pretty confident with your diagnostic of my car problems but the car does still seem to drive OK with the engine light on and with (virtually?) no reduction in power. Cruise control still works and it doesn't feel like it's in a limp-home mode.

I have no idea if my car has the latest software or not. It's certainly nothing I've had done and I'm pretty sure my Dad never had it done when he owned the car before me.

If it is either of these sensors (including CPS) is it an expensive job would you say? I'm planning to sell this car in the next 6 to 12 months to get a newer 9-5 Aero. I don't want to spend too much money keeping this one running in the meantime. Am I causing more damage driving it whilst it's like this?

Last question - can anyone recommend a garage around Peterborough that has the necessary Saab Tech 2 diagnostics and decent prices?

Thanks all, and again to sgould for all the info.

[sgould]

I'm not sure that I'm confident that I know your problem!!

All I have done is quote the Saab workshop manual for P1230 and try and explain that the pedal and throttle butterfly motor also operate resistors that try and cancel each other out.

The fact that you haven't got all the symptoms of P1230 leads to some doubt about a diagnosis.

The two resistors moving and cancelling is not an instant operation, it takes a few milliseconds to do it.  As far as I am aware all the software upgrade did was to allow more time before it threw a CEL and limp-home.

As far as a Tech2 source.  I know of no one near you, but I can post these links.

http://the-saab-specialist-register.com/independent-saab-specialists/

http://www.saabparts.com/en-gb/uk/

[Audax]

You could try Leelac Saab who are near St Neots, the guy there is competent and has Tech-II and is cheap too. The only issue I found was that getting hold of him can be tricky at times but he will work on your car while you wait.

[pompey]

Thanks again for your info sgould and your suggestion of a garage audax.

I've got it booked in with a ex-Saab dealer and, for the princely (pricey!) sum of £55 they'll hook it up to their Saab Tech 2 equipment and see what's what.

An interesting thing happened yesterday though.... Well, I say interesting but it's not really and I'm going to tell you anyway...

I DID only have the engine warning light on and the car had felt pretty normal apart from that - cruise control seemed to work and the turbo span up to what I think were the usual levels. To test the power on my way to wok I took it on the A1M for a few miles and it seemed normal. However, pulling off the slip road to work I gave it some beans and the TC kicked in as you'd expect but then I hear "tick, tick, tick" like I've turned my hazards on a the TC light is now permanently on too. Also, I can no longer switch cruise control on.

I'm going to do the good old carb cleaner spray check for any pipe leaks tomorrow but if that finds nothing of any use I'll be sure to show the ex-Saab dealership who are checking it on Friday this thread.

Here's hoping it's going to be relatively cheap to fix!

[Audax]

Sounds like it has gone into proper limp home mode. Ask about Trionic 7 software upgrade and get the throttle body cleaned and reset. If it does it again after that then it's likely to be new throttle body time. A new genuine throttle body is going to be around £300+fitting etc. I note leelac are selling secondhand ones on ebay for £65, I doubt leelac would charge more than £55 labour for the Tech-2 and fitting a replacement throttle body if it is at fault.

[pompey]

Thanks, Audax. I'll try and call Leelac tomorrow and see when they might be able to look at the car. They're not that far from me really and I wish I'd known of them before I used Offord Motors which is a fraction less distance because they were appalling!

[Audax]

It's further for me to get to Leelac (15 miles from me) than it is to Offord (10 miles from me) but having seen some things from Offord in the past I doubt I'd ever go there. There is also Two Stroke to Turbo (10 miles from me but another 10 miles further south for you) who I've heard mixed and slightly worrying things about but I only ever used them for parts and they were very helpful and good for that.

[pompey]

Result! Booked in with Leelac for this Saturday and only £35 per hour.

[Audax]

One thing I should have mentioned, make sure you take a map and their phone number with you to find Leelac... 

(Some satnavs will take you to the wrong side of the airfield!)

[pompey]

Yeah, I can see what you mean. The guy gave me some directions and then I was able to find the area on Google maps and then use good old Street View to see the actual entrance to the airfield industrial estate so I've picked up a postcode from that point that I'll use in my phone on Saturday. It looks pretty straight forward so, when I finally buy myself a newer model 9-5 Aero, I think this guy might become my new go-to man for the big stuff!

[pompey]

Wow! What a great guy! He's done the software upgrade and swapped my radio unit for less than the ex-dealership were going to charge and with no doubt a far more interesting conversation - this man seems to live and breath Saabs. He was telling me about some VERY nice ones in his collection and some fun ones he's tweaked up.

I'll be using this guy again for any big, specialist jobs.

So far the car seems fine and may even have a bit more oomph but that might've the placebo effect!

[Audax]

Did he say if he thought the software upgrade would resolve or did he say you'll have to wait and see?

[pompey]

He kinda took the lead from me from what I'd said when I called him explaining the symptoms and the advice I'd received here. But the price he quoted me for if he does have to change the TB seemed VERY reasonable so I am more than happy to see how it goes. So far it's looking good - I've done several short journeys after the drive back from Leelac Saab and all seems good.

Thanks again to you guys for your help and advice!