My 3200 GT hard to start

[ledlights]

Hi,

0x just means its a hex number in unidiag. As you're plugged into the engine ECU it's bound to be a P descriptor hence P1225. That code relates to the TB potentiometer, recon or not there's something amiss there.

I'm still pretty convinced that your non-starting issue is related to the RFID code and induction loop... I could be wrong though.

The ECU route has got to be your last port of call, surely? If the engine starts when you truncate the systems check, there can't be too much wrong.

Steve

 

[Alecci]

Time for an update here then.

I finally got round to both trying the red master key and measuring the voltage output from the PP.

Master Key:

No change in issues about starting, but since trying it Key Code Light hasn't been lit once, not even after engine started. In fact, not even the CEL any longer shows up after starting the engine until I press the accelerator.

Pedal Potentiometer Voltage:

I received some instructions to go along with the new contactless pedal potentiometer. It tells me to measure the voltage output in the PP connector between either the black and the white or the black and the yellow wires. Voltage output should be 0.35-0.5 Volts for idle and 3.1-3.7 Volts for WOT unless my memory fails me.

When measuring, output would not rise above 0.005 Volts for neither idle nor WOT, but the weird thing is that it would climb to 0.46 Volts maximum at about half-throttle. We tried several times using both of the indicated combinations of wires, with the same results. We tried adjusting the sensor according to the instructions, but only succeeded in lowering the half-throttle output to about 0.21 Volts maximum, with idle and WOT unchanged.

While I myself am personally a total newbie when it comes to electrics and electronics, my brother-in-law is at least a qualified electrician, if not specialized in any way in vehicles and their electronics. I figure he at least ought to know how to use the multimeter and make the correct settings.

I wish I had a verified fully-functioning standard PP to compare with, but my guesses are my standard one is more or less rubbish.

Is there any way - or meaningful one at least - to measure the voltage at the other end of the system, i.e. throttle-body side?

 

[CatmanV2]

Pedal pot is dud, in my humble opinion.

C

 

[ledlights]

Hi Alex,

Sounds like the RFID chip might be either missing or dud in your normal key, hence the key light error.

On the pedal pot, your readings sound wrong. I'm not saying that you've measured anything incorrectly but they don't tally with anything I've seen. The pot normally fails by wearing through a section of the resistive material.

I think you're onto the problem now....

 

[Alecci]

Hi Alex,

Sounds like the RFID chip might be either missing or dud in your normal key, hence the key light error.

On the pedal pot, your readings sound wrong. I'm not saying that you've measured anything incorrectly but they don't tally with anything I've seen. The pot normally fails by wearing through a section of the resistive material.

I think you're onto the problem now....

As always, much obliged for your input, mate. Don't know if you missed it, but these readings were taken using the brand new contactless pedal potentiometer (which shouldn't have any resistive material?).

 

[ledlights]

Yes, sorry missed that. By the sound of it, the new part is faulty. You're right, the contactless one uses a Hall effect sensor that links to the rotor by a magnetic field, so no resistive material.

I saw this post and thought it might be of use: http://www.maseratiforum.co.uk/OBDII_P600_error%/m_66941/tm.htm

Steve

 

[davy83]

Hi Alecci - The pedal pot is certainly not right. Did you check the power supply voltage? Shoudl be a 5V DC on the red wire (I think). Is the pedal pot one of mine? If so this is the first one thats ever been wrong. Let me know i will get you a replacement by post if its one of mine and I will have a look at the one you have. At least you have one of your problems there. Does not explain the lock warning but the lack of engine response would be caused by this pedal sensor not working.

 

[NickP]

I was going to ask where did you source a contactless pedal pot, last I heard this was still in dev, davy can you give me any info on your please?

 

[davy83]

I have made and sold 12 of these in total and in 3 years no problems. I have had one on my own car for 3.5 years and i still think its smoother and easier to control. idle on start up seems better. I can make them as required, I have a couple I think in store for any one who wants one. Alecci is the first person to have had problems so i may be speaking too soon!! PM me if you are interested i have an install instruction with some photos shows you what it looks like and so on. Its a mixture of a custom made transducer from a reputable UK sensor company who made this to my spec, and its mounted in a machined metal body, with sealed precision bearings. It also allows a little adjustment so you can get the idle and full throttle set up just right. I have a couple of prototypes made for the 4200 but have been so busy I have not finished them yet.

 

[Alecci]

Hi there,

Sorry for not replying any sooner, been much work lately and ended up with a migraine yesterday.

Davy mate, the pedal sensor is supplied by you. I may have to take you up on your kind offer to rectify things, but before I put you through the trouble I'll measure the power supply as you suggested, and also once again try and measure the other readings in order to make sure it's not the human factor at fault here.

I will also try to measure the standard one that I still firmly believe is dud (as I received a DTC for it), so that I may have something to compare with.

I've also been told that the new contactless throttlebody can be at fault, is there any way to measure this and what readings should I expect if there is? I figure a good way to test the performance of the throttlebody would be to loosen the intake house and check for movement while the accelerator is pressed, but if the pedal sensor is faulty then I guess there's no signal - or a too weak one - that tells the throttlebody how to operate.

 

[ledlights]

Hi Alex,

I don't think you should try to move the butterfly when it's in it's open position i.e. when the ignition is on and the throttle is fully depressed. From what I've seen, any check of the TB should be done with the ignition off and the butterfly can then be safely moved through its range to check for sticking/jamming both from the idle position to fully open and from the idle to fully closed. Any grittiness in its movement is bad news - the butterfly should move very smoothly as it's mounted in ball races.

I think that if the pedal pot is faulty, get that changed first then move onto the TB if a fault is still present?

Steve

 

[Alecci]

Update time again.

I measured and adjustred the contactless pedal sensor today, and ended up finally getting the correct voltage outputs. I ran the throttle reset procedure and then tried starting the car.

The car still will not start if I let the diagnostic check complete, but there is no CEL until I press the accelerator ever so gently, then it lits up instantly. My take on this at the moment is that we can at least take the pedal sensor of the list of probable causes now that I've firmly established it does what it's supposed to and that the outputs are correct.

As for the DBW system I think the next item to double-check would be the equally brand new throttlebody. Is there any way to check that the operation of the throttlebody performs as intended?

After that, I don't know what to look for... Any suggestions?

Hi Alex,

I don't think you should try to move the butterfly when it's in it's open position i.e. when the ignition is on and the throttle is fully depressed. From what I've seen, any check of the TB should be done with the ignition off and the butterfly can then be safely moved through its range to check for sticking/jamming both from the idle position to fully open and from the idle to fully closed. Any grittiness in its movement is bad news - the butterfly should move very smoothly as it's mounted in ball races.

I think that if the pedal pot is faulty, get that changed first then move onto the TB if a fault is still present?

Steve

Steve mate,

I tried moving the butterfly of my old TB, that has been removed from the car. It's dead stuck, whereas I think it ought to move rather freely whether it's in the car or not. I'd never try to move it while mounted in the car and engine running.

 

[ledlights]

Hi Alex,

Your old TB sounds like it has a problem with corrosion between the rotor and the coil. If you're interested. You can see the construction and symptoms if you search for Volvo TB problems on google. When you posted, I was concerned that you would have blown the servo driver in the TB if you'd tried to move the butterfly when the ignition was on.... Sorry if I misunderstood your post.

It still sounds like you've got 2 problems, the first sounds like the RFID in the key (when you tried the red key you didn't get the key error, did you?) and the second sounds like the TB now you've eliminated the pedal pot.

Steve

 

[Alecci]

Is there any way to check that the operation of the throttlebody performs as intended?

Hi gentlemen,

Problems with the car persists. Any thoughts on what I quoted above?

 

[davy83]

Hi Alecci. Its really pointing at your TB and the problem is that if there is a problem with the rotary sensors or the rotary motors, it s a delicate and fairly complex device. Beyond checking that the butterfly moves freely, its really hard to work out exactly whats going on inside!! I think boomerang in Holland does some work on TB's perhaps he might pitch in here and see if you could maybe send it to him for a check up!. The only other thing I can think of is to see if you can get another TB on loan from some one like David Askew or Bill McGrath and swap it out, if the replacement works then you know what the problem is! The RFID problem really requires you to start replacing either the sensor under the steering column or the key or immobiliser? The place in Wales who used to do good work on the immobilisers and keys have stopped now as the bloke who used to do it died. I am not sure if there are other places who can decode the key and immobiliser codes and sync is all up again? There are a few places who advertise immobiliser decoding and they might be able to look at the immobiliser and key and work out the problem? You could try to get a replacement immobiliser and keys from a breaker and swap out the RFID chips in your keys (swap the bodies) not sure if this can be done but it might work.

 

[Alecci]

Hi Alecci. Its really pointing at your TB and the problem is that if there is a problem with the rotary sensors or the rotary motors, it s a delicate and fairly complex device. Beyond checking that the butterfly moves freely, its really hard to work out exactly whats going on inside!! I think boomerang in Holland does some work on TB's perhaps he might pitch in here and see if you could maybe send it to him for a check up!. The only other thing I can think of is to see if you can get another TB on loan from some one like David Askew or Bill McGrath and swap it out, if the replacement works then you know what the problem is! The RFID problem really requires you to start replacing either the sensor under the steering column or the key or immobiliser? The place in Wales who used to do good work on the immobilisers and keys have stopped now as the bloke who used to do it died. I am not sure if there are other places who can decode the key and immobiliser codes and sync is all up again? There are a few places who advertise immobiliser decoding and they might be able to look at the immobiliser and key and work out the problem? You could try to get a replacement immobiliser and keys from a breaker and swap out the RFID chips in your keys (swap the bodies) not sure if this can be done but it might work.

Dave mate,

The TB is a brand new contactless one purchased from Bill, since he offers warranty on them (unless I'm mistaken) I would attempt to go for a swap there, but I wanted to know if there's any way of checking whether it's really at fault - as we did the pedal sensor - before putting him through the hassle. Is there any voltages one can measure or something similar?

 

[Contigo]

Remove the inlet pipes and check to see that the butterfly open and closes. Similar to this video here.

http://www.youtube.com/watch?v=pDWtaBZUhy8

I assume you have checked your rpm/tdc sensor? The weird thing about your car is that it does actually start if you override the engine checks.

 

[Contigo]

http://www.abacuscaralarms.co.uk/re-coding-meta-alarms/maserati.html

 

[davy83]

Good link Contigo!!! its good news that some is still able to work on this

 

[Alecci]

The thread continues, regrettably...

Remove the inlet pipes and check to see that the butterfly open and closes. Similar to this video here.

http://www.youtube.com/watch?v=pDWtaBZUhy8

I assume you have checked your rpm/tdc sensor? The weird thing about your car is that it does actually start if you override the engine checks.

I have now verified that the butterfly doesn't move a millimeter when pressing the accelerator.

If you by RPM/TDC sensor mean the CRANKSHAFT SENSOR (585069401) then it has been replaced with a brand new item.