Volvo S80 diagnostic rubbish

[garethj]

I don't want to turn this into another "modern cars are rubbish" thing, because it's not as simple as that. But modern mechanics are rubbish, I'm just reorganising my hate-filled card index so they're next to the estate agents. If it continues they'll be up there with the ambulance chasers.

 

This 1999 Volvo S80 has been our family car for three years, it's a 2.4 petrol and quite a nice thing to doze in on the motorways. About two years ago, the engine management light came on, so we took it to a local garage who diagnosed a buggered catalytic converter. They changed this for an aftermarket one, about £350. After a month, the engine management light came back on so they swapped the cat under warranty. A couple of months later and the light is back on, so they swap both oxygen sensors for another £300ish.

 

Time passes, the light comes back on, the code still says it's the catalytic converter, the garage shrugs their shoulders.

 

We take it to another garage, he sticks his code reader on and reckons the other garage put the sensors on the wrong way, so they swap the connectors around. The light stays off for about a week (this is just because they clear the code and it takes a week to do a complete drive cycle - certain time at 30mph, certain time at 50mph etc) then the light comes back on. The garage shrugs their shoulders.

 

Next garage says the other places were only guessing, they've got the real Volvo diagnostics which read the codes in the order they happen and it's the throttle body. This is a common failing on early petrol S80s apparently, it needs this and everything will be fine. £350, plus vat, fitting, software flash etc. After a while the engine management light comes back on.

 

They say that the oxygen sensors are connected the wrong way around, it needs two new oxygen sensors, another £300. This was done on Friday and I took the car for a long drive yesterday, guess what happened to the engine management light? You'll never guess? I can't even face writing it so this should give you a clue:

 

Taking it back to the garage again tomorrow, they hinted that it might need a proper Volvo catalytic converter but we'll see what the codes say.

 

It's also done normal car things, like needed 4 new tyres, brake pads, MoT, road tax, basically in the last 2 months this car has cost 3 times what my 740 cost to buy.

 

I'm thinking along the lines of a gallon of petrol and box of matches, anyone have a better idea?

[Guest]

I don't want to turn this into another "modern cars are rubbish" thing, because it's not as simple as that.

 

I'm thinking along the lines of a gallon of petrol and box of matches, anyone have a better idea?

 

I feel your pain, brother.

These modern mo-chines are hoopty. Lord knows what the future shiteist will do when the diagnostic equipment has been binned.

[Mr_Bo11ox]

These so-called 'Mechanics' should be killed. is there another industry where you can pay a professional several hundred pounds for his services, and when he fails completely to solve your problem, just shrugs his shoulders and invites you to spend a few more hundred quid with him? Hopeless.

 

Maybe you could tie one of them into some sort of deal where they guarantee their work for 6 months or something, obv they'd have to tell you exactly what their diagnostic gizmo was telling them, otherwise they would just say 'oh its a new fault' when you were back a week later with the light on.

[Mr_Bo11ox]

Lord knows what the future shiteist will do when the diagnostic equipment has been binned.

 

He'll just diagnose his shite issues via a bluetooth app on his I-phone and a £2.99 dongle off ebay that piugs into the cig lighter and talks to the ECU's, no need for pros and diagnostic gear. The app will probably even order a replacement part off ebay automatically.

[Guest]

 

Maybe you could tie one of them into some sort of deal where they guarantee their work for 6 months or something, obv they'd have to tell you exactly what their diagnostic gizmo was telling them, otherwise they would just say 'oh its a new fault' when you were back a week later with the light on.

 

Yeah, I've tried that one with several 'reputable' garages when they were 'really sure' that wheel balancing would 'definitely solve' the wheel wobble issue on my C4.

 

Me: So if this doesn't solve it, can I have my money back?

Garage: Er, why?

Me: Because if it hasn't solved the problem that you swore blind to me a minute ago would be solved by wheel balancing, I've just wasted £40. So will it solve the problem or not?

Garage: Well we've spent time sorting your car out so you'd have to pay us.

Me: But if that doesn't solve the problem, why should I pay you?

 

etc.............

[Luxobarges_Are_Us]

Lord knows what the future shiteist will do when the diagnostic equipment has been binned.

 

He'll just diagnose his shite issues via a bluetooth app on his I-phone and a £2.99 dongle off ebay that piugs into the cig lighter and talks to the ECU's, no need for pros and diagnostic gear. The app will probably even order a completely inappropriate replacement part off ebay automatically.

 

Fixed...

[Pete-M]

 

Maybe you could tie one of them into some sort of deal where they guarantee their work for 6 months or something, obv they'd have to tell you exactly what their diagnostic gizmo was telling them, otherwise they would just say 'oh its a new fault' when you were back a week later with the light on.

 

Yeah, I've tried that one with several 'reputable' garages when they were 'really sure' that wheel balancing would 'definitely solve' the wheel wobble issue on my C4.

 

Wheel balancing did solve most of the wheel wobble issue on your C4

[garethj]

Lord knows what the future shiteist will do when the diagnostic equipment has been binned.

To be honest - fuck the future. Right now the car is current, there's not one bloke you've got to drag out of retirement who remembered fixing them 30 years ago, all the equipment is here now.

 

But it's still not easy.

 

I'm reluctant to take it to the dealer, last time it went there they broke the front hub, leaving the main bolt rattling around inside the hubcap

[Guest]

 

Maybe you could tie one of them into some sort of deal where they guarantee their work for 6 months or something, obv they'd have to tell you exactly what their diagnostic gizmo was telling them, otherwise they would just say 'oh its a new fault' when you were back a week later with the light on.

 

Yeah, I've tried that one with several 'reputable' garages when they were 'really sure' that wheel balancing would 'definitely solve' the wheel wobble issue on my C4.

 

Wheel balancing did solve most of the wheel wobble issue on your C4

 

Yeah, but only because your garage actually bothered to balance the wheels properly, unlike 4 places near me who couldn't be arsed and then 'couldn't understand' why the steering wheel vibrated.

[scaryoldcortina]

These so-called 'Mechanics' should be killed. is there another industry where you can pay a professional several hundred pounds for his services, and when he fails completely to solve your problem, just shrugs his shoulders and invites you to spend a few more hundred quid with him? Hopeless.

 

err... Building? Plumbing? Block paving? Law? Debt counselling? Medicine, dentistry, chiropracty, advertising..... ah feck it. The list is endless. Anyone claiming to be a professional anything is going to take your eyeballs out every time you visit them!

 

 

Back to problem.... I have frequently seen code readers insist that the catalyst or oxygen sensor has failed when in fact the car needs a £20 coolant temp sensor changed. In fact, I fixed one like that today.

 

 

Oh yeah, and I use a homemade (ELM323) adapter and a cheapo (free, actually) laptop running linux with no software. I talk to the car via a serial terminal (8N1, 9600) and convert the codes from hex in my head.

[worldofceri]

...is there another industry where you can pay a professional several hundred pounds for his services, and when he fails completely to solve your problem, just shrugs his shoulders and invites you to spend a few more hundred quid with him?

 

Autoshite Repair SErvices:

 

"No Fix, No Fee!"

[garethj]

Back to problem.... I have frequently seen code readers insist that the catalyst or oxygen sensor has failed when in fact the car needs a £20 coolant temp sensor changed. In fact, I fixed one like that today.

That's interesting. Perhaps it's time I got a Haynes manual and went looking for a coolant temp sensor.

Oh yeah, and I use a homemade (ELM323) adapter and a cheapo (free, actually) laptop running linux with no software. I talk to the car via a serial terminal (8N1, 9600) and convert the codes from hex in my head.

I think we need to know more about this - sounds invaluable, like the 21st century equivalent of a mole grips

[Pillock]

Yeah SoC - can you supply any more information about home made fault code readers?

[scaryoldcortina]

Seriously? OK then.

 

I made my adapters years ago using the ELM 32x series chips and a MAX232 to do serial to RS232 conversion - you can now get an all singing/dancing ELM327 which autodetects OBD protocol and does the RS232 conversion too, PDF data sheet is here, I'm thinking of getting one and building a new adapter to replace the 4 I carry at the moment. You could also buy one ready made, they ain't expensive really. Connect adapter to serial port on laptop (or USB via a cable adapter)

 

Now, the software side...

OBD is really really simple. If you only want to read and erase codes this is all you need to do..

Open a suitable serial terminal program (hyperterm, GTKterm etc) set it to read the port your OBD adapter is plugged into (ttyUSB0, tty0, whatever) and set bbaud and protocol to 8n1,9600 (same as pretty much everything else, it's probably the default setting)

Plug the interface into the car, switch the ignition to "run" but don't start it (this is KOEO - key on, engine off mode)

If you got the port and baud rate right, the terminal screen will say "ELM 327, ready" or similar and give you a ">" prompt.

Type "03" and return

Reply will be 43 00 00 00 00 00 00 (if there are no stored codes) the 43 is the command acknowlegment, each pair of 00's is a fault code (3 per line). If there are more than 3 codes stored another 43 line will follow until there are no more to report.

Real screenshot example - this is showing 0172 as a fault code - the first 0 means P0 and the rest (conveniently) means 172 so the code is P0172, which means fuel system rich. This golf is going to get a coolant temp sensor fitted first.

 

To clear codes, type "04" at the prompt, car will reply with "44" and the management light goes out.

 

More info on OBD can be found via google.

[Morgan84]

Don't be affraid to take it to a Volvo main dealer;they have ALL the correct diagnostic equipment and software for your car,and therefor have absolutely NO excuse in not being able to solve whats actually bugging your car.Yes,they might charge £90 to do a diagnostic,but its cheaper than all the hundreds you've had to fork out already which haven't cured the problem,only made you want to destroy the damned car instead.I know how it feels to have a car which does its best to destroy your soul !

 

I usually say with engine management lamps,providing the cars driving ok,just ignore the damned thing,and wait till MOT time,and if it passes the emissions test,then leave it alone.

[garethj]

soc - that's interesting. Is it just some veroboard, an OBD plug and USB connection to add to the IC for a diagnostic system?

 

Don't be affraid to take it to a Volvo main dealer;they have ALL the correct diagnostic equipment and software for your car,and therefor have absolutely NO excuse in not being able to solve whats actually bugging your car.Yes,they might charge £90 to do a diagnostic,but its cheaper than all the hundreds you've had to fork out already which haven't cured the problem

Yeahbut - now the car has got an aftermarket catalytic converter, so I'm a bit concerned they'll say it needs a proper Volvo one before they can do the diagnostics. And that's ££££. Plus after they left the hub bolt rattling inside the hubcap last time, I'm more than a bit nervous leaving them the keys again.

I usually say with engine management lamps,providing the cars driving ok,just ignore the damned thing,and wait till MOT time,and if it passes the emissions test,then leave it alone.

You could be right, but it's a bit juddery too, when you're driving along at motorway speeds every 30 seconds or so it'll miss. When you've driven knackered old sheds as long as me, that's a heart in the mouth moment as you're just ready to bang the clutch pedal down, stick the left indicator on and try to nurse it over to the hard shoulder

[Negative Creep]

 

Maybe you could tie one of them into some sort of deal where they guarantee their work for 6 months or something, obv they'd have to tell you exactly what their diagnostic gizmo was telling them, otherwise they would just say 'oh its a new fault' when you were back a week later with the light on.

 

Yeah, I've tried that one with several 'reputable' garages when they were 'really sure' that wheel balancing would 'definitely solve' the wheel wobble issue on my C4.

 

Me: So if this doesn't solve it, can I have my money back?

Garage: Er, why?

Me: Because if it hasn't solved the problem that you swore blind to me a minute ago would be solved by wheel balancing, I've just wasted £40. So will it solve the problem or not?

Garage: Well we've spent time sorting your car out so you'd have to pay us.

Me: But if that doesn't solve the problem, why should I pay you?

 

etc.............

 

 

I had a similar thing where wheel balancing fialed to cure the wobble on the BMW. Rang the garage up again to be told "your brakes must be sticking then", the fact it passed an MOT the previous week apparently meaning nothing. Didn't even say bring it in and we'll have a look, just a case of not our problem go somewhere else. I ordered new spigot rings and that solved the problem. So that was £30 completely wasted

[r.welfare]

Interesting, Gareth. I'm in a similar situation with my wife's Avensis - EML permanently lit due to codes P0420 and P0430 (catalytic converters not working at optimum efficiency or some such). Four oxygen sensors and a new coolant sensor later and it still does it - puts the damn thing on within 10 miles of a reset.

 

It does the occasional judder thing and is a bit flaccid under 3,000 revs, but otherwise runs smooth as silk and is still doing decent MPGs - and passed the last 2 MOT's fine with the light on (the only advisory!) as emissions were on-spec. Trouble is, of course, that the new MOT regs from 1.1.12 will mean an automatic fail with the light on...so I may be going down the new cat route as well. Which, like you, will mean £££ as the damn thing has three, and my money's on the two built into the exhaust manifold. £280 aftermarket, more like £600 from Toyota.

 

Looking at Toyota forums, this is a known problem which the dealer can happily fix with the aforementioned cats, 4 oxygen sensors and a new ECU (apparently it can't be reflashed) at a cost of c. £1,800 - not much point in that when the car only cost £1,500 and is worth about a grand now.

 

My last-ditch attempt will be to clean out the throttle body, put in some Cataclean and apply an Italian tune-up...and investigate whether I can rig the EML to another warning light instead...

[scaryoldcortina]

The ABS lamp trick would work for the EML at test time

 

Disconnect the offending lamp from the loom, then use a 555 timer IC in monostable mode to switch the light on with the ignition, and out after 3 seconds.

[garethj]

The thing that's just come back to me about building an OBD rig is - reading the codes isn't the problem. What I've got here, is a case of the codes being wrong, or interpreted wrong.

 

That, and flushing the thick end of a grand down the toilet over the last couple of months is making me a bit tetchy

[scaryoldcortina]

yeah, the real problem with diagnostic trouble codes is that they are not a solution, merely a hint. "Bank 01 oxygen sensor reading high" does not mean that it is faulty, it just means it reads a rich mixture going into the catalyst. Most chimps don't realize that, change whatever is mentioned in the fault code and give the car back after a code clear...

[andrew e]

Hey Scary you need a thread with pictures for this ridculously usefull data. My permantly pissed electronic lecturer made me build something with a 555 chip nearly 20 years ago, but I never thought it might have a use! Tick VG

[scaryoldcortina]

Are all electronics lecturers pissheads? All I really remember from back then is that we all pissed ourselves laughing every time he said "astable multivibrator"

 

The 555 trick is laughably simple, and the solution to all warning lamp related MoT problems.

Use this basic circuit. R1 and C1 determine the "on" time, put a 4.7uF capacitor where the trigger switch is so it only trips once, the chip can direct drive a small lamp easily from the output pin.

[dollywobbler]

Nice one SOC. My brain is struggling to comprehend what you've written, but this is the tinkering of the future. I'd better try and get my head around it...

[garethj]

News from the garage, it needs a new catalytic converter. When I asked how sure they were a new cat would fix it, the reply was “pretty sureâ€Â. I’m going to overshoot my allowance of rolleyes smilies at this rate.

 

Verdict: arse

[Mr_Bo11ox]

wankers

[Rocket88]

yeah, the real problem with diagnostic trouble codes is that they are not a solution, merely a hint. "Bank 01 oxygen sensor reading high" does not mean that it is faulty, it just means it reads a rich mixture going into the catalyst. Most chimps don't realize that, change whatever is mentioned in the fault code and give the car back after a code clear...

 

I totally agree. Trying to teach someone who may be a whizz at mechanical stuff diagnostics is like attempting to instruct Chopin how to bowl leg breaks. They are two completely different fields of expertise, and there aren't many people who can master both. Plus Volvo and Saab electronics are a bit strange anyway, although not as contrary as French stuff. The Germans [surprise surprise] have the most logical diagnostic set-ups.

[dollywobbler]

The real genius is indeed correctly decoding the fault. Was at a Landy specialist the other day. A Disco 2 TD5 comes in, misfiring and clearly only running on four cylinders. Chap hooks up his computer, sees that the fuelling is all to cock on one cylinder. Knackered injector? Duff sensor somewhere? No. He pulls the top off the engine, removes the wiring to the injectors and cleans it all up. Yes, the wiring is INSIDE the cam cover. Connects it all back up and bingo. Running beautifully on 5. A common fault apparently - but I wonder how many people have ended up with such a cheap fix...

[oldford]

To some extent the owners bring it on themselves. The scenario of the car needs a new cat, it'll cost £600 for a genuine one or £250 for a pattern one, what's going to happen? the instruction from the owner will be get the £250 one.

 

From experience, the £250 one is £250 for a reason, they contain less material and don't fit exactly the same. We had this on a Fabia, the lambda probe hole was further round, (straining the cable and very close to the floor) and it kept popping the light on every couple of weeks with an efficiency fault. You fall into the trap of, it's had a new cat, the fault must be something else. You spend time cleaning and resetting the throttle body, erasing learned values and checking for implausible signals from a myriad of sensors every time the car comes back, you spend time on it which you know the customer is not willing to pay for. You turn full circle and get a genuine second hand cat and the problems solved. Lesson learnt, make the customer aware that a cheap cat may not be upto the job.

 

We had an old lady with a Fabia in for an ABS fault, she had gone to the local dealer where they fitted a new ABS unit at £650 and it didn't cure it. We code read it (at our standard charge), fixed it in 10 minutes and it was fine, cost her £50 in total. When she collected the car she was a bit mistrusting of our repair, we had to demonstrate that the system was working exactly as the manufacturer intended, maybe if she had had a much larger bill, she may have been more accepting that it was fixed. To my knowledge she never went back to the dealer for an explaination or some money back on her original £650 invoice.

 

It's interpreting the codes that's important, I've seen some VW 1.8s with a camshaft sensor/crankshaft sensor correlation error which doesn't mean that there's a problem with either sensor just the the cam belt has been fitted a tooth out, despite the person who fitted the belt swears blind the the timings perfect.

[Morgan84]

Here's a thought - something I wouldn't usually reccomend - are there any Volvo breakers near you ? Ask if they have a car in with a compatible cat,as I'm sure a good used one is worth trying if its sensible money.If it works,you can then maybe consider investing in a new one IF its deemed necessary. Sounds hard work I know,but sounds like you've had a expensive time with this one