check engine light keeps coming on. (Full Version)

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cloudy9 -> check engine light keeps coming on. (9/6/2009 17:12:14)

Hello. I have a 3200gt and the check engine light keeps coming on. When it does i lose power. The car still goes but does not accelerate. I then turn the engine off and leave for 5 mins, turn it back on and its ok. I have taken it to lancasters maserati and another specialist in essex. I have had two new potentiometers, 1 left hand oxygen sensor, 1 spark plug sensor, plus ive had all the electrical connections replaced. The fault still shows up as being the potentiometer.
Can anyone please help me.

davy83 -> RE: check engine light keeps coming on. (12/6/2009 10:42:25)

one of the problems that can beset these cars is poor wiring connections, i rather suspect you have a bad wiring connection some where.

I got a local automotive electrical specialist to go over my 3200 and just clean up and replace bad conenctors and this removed most of the sporadic warning lights and the fuse which used to blow regularly. They did not replace any sensors or do any thing other than inspect and fix the wiring.

I still occasionally get the engine warning light and it usually is complaining about the throttle pot. I bought an ODBII ECU reader so I ismply log these error warnings and then clear them, i can give you a link to the web site i got the reader from it was not expensive.

having the wiring checked might be worth a try. If you are into the details i have a workshop manual and could try to send you copies of wiring diagrams for the relevant bits of the car.

Hope this helps

cloudy9 -> RE: check engine light keeps coming on. (16/6/2009 21:37:29)

Thank you for your help, it is much appreciated. I will have the wiring checked over again. I have had two maserati specialists look at the wiring and alot of it has been changed. Unfortunity when it comes to a problem like this, i don't really have a clue. Its just strange that noboby so far seems to be able to find the problem. Its bloody irriatating.

Phil H -> RE: check engine light keeps coming on. (16/6/2009 21:58:22)


You said that various parts have been changed (Oxy Sensor, Plug Sensor, Connectors), but were they changed on spec or because fault codes identified their circuits as the culprits? Are you paying for the work, or is it being done under warranty?


cloudy9 -> RE: check engine light keeps coming on. (17/6/2009 19:20:10)

Hello. Ive had it tested 3 times in the past on the diagnostics and had faults cleared and the car has been fine, but only short term. Last time it said i had a problem with the potentiometer, despite having had 2 new ones fitted. I took it to a place in halstead essex which specialisers in maseratis, ferraris and lambos. He then changed all the connectors. The engine light then stayed off and the car was fine for 450miles. The car is a w reg so its not under warranty and its getting quite expensive. I start the car and drive off and its fine, but then all of a sudden the check engine light comes on and the revs/acceleration is restricted. It may be a dodgy wire, but i would of thought it would have been discovered by now. I don't think its the throttle body. Just wondered if anyone had come acrossed a similar problem? Thank you for your replies so far.

Nigelo -> RE: check engine light keeps coming on. (18/6/2009 11:04:27)

The fact that you have driven 450 miles before a problem surfaced (or resurfaced) does not neccessarily mean it is a recurrence of the same problem. You cannot diagnose these errors by speculation, guesswork and random replacement of parts - You will need to get a full diagnostic check on an SD2/3 to pinpoint precisely what is the cause of your current problem, so suggest you take it back to Rob Grimaldi for this purpose

hope this helps

Jeremydb -> RE: check engine light keeps coming on. (28/7/2009 12:28:26)

Cloudy -

A similar thing happened to my 3200. The engine warning light came on and it went into limp-home mode (i.e. engine not allowed to rev over about 3000rpm). Next day, all was fine. And diagnostics at its next service didn't pick anything up.
As you'll know, the point of limp-home mode is to safeguard the engine from knocking and I did hear that there is a sensor for knocking that can become affected by moisture so gives a false reading and so sends the car into limp-home mode. Once the sensor is dried up, all is fine, hence the problem can be intermittent.

ironass -> RE: check engine light keeps coming on. (21/8/2009 22:18:59)

As a new member glad to hear somebody else has the same problem.  First time round the engine light came on and car entered 'limp home' mode. Reset at the specialist (nothing wrong with accelerator pot) and same thing happened again. On restart worked fine until all up to temperature then throttle went dead again.  In neutral throttle worked fine.  Specialist now tells me that I need throttle pot. @ £400+.  Also told me that 100% throttle required every trip to ensure proper working.  I've done this at the potential expense of my licence but without effect (see above).  Now I wonder whether this expense will really fix the problem or I will be left with a supercar with the performance of a Daihatsu Charade.  Can anybody provide me with a definitive answer or at least some credible hypotheses on what is the real cause of this? Thanks.

lozcb -> RE: check engine light keeps coming on. (22/8/2009 7:32:10)

Ironass, as you will see i have a 4200 , and forgive me if my speculation if its  misguided , but from previous posts on this subject  it could possibly be a leaking hose directly above the knock sensor , which i beleive is in the center of the V  , what had tended ot happen to some folks is when the car gets up to temp the pressure in the hose forces a leak directly onto the knock sensor causing the cel light/limp home mode ,  hopefully change the hose or fix the leak and just maybe that might be the answer to your probs , apparently a bit a of pig of job , Conaero had the same problem  and listed a how to do on here somewhere  perhaps it worth sending him (matt) a PM

regards loz 

catalan3200 -> RE: check engine light keeps coming on. (22/8/2009 10:19:55)

I have had the same problem after having my throttle body refurbed by David Askew and replaced at Grimaldi. Took the car back to Rob who hooked it up to the SD and the potentiometer fault was diagnosed. He was trying to get everything sorted at the workshop before going on holiday but still gave me his time and enthusiasm FOC.

Rob believes that the problem could be wiring connectors and checked the key connectors. After the visit the problem kept re-occuring and became a real pain. The re-set sometimes took 6/7 attempts before the CEL went out and everything returned to normal. I always wait for all lights to go out before starting her up so it could be quite time-consuming.

However for the last month or so everything has been fine. No issues at all.

Canate -> RE: check engine light keeps coming on. (1/10/2009 21:18:51)

Hi, I have a 3200 GT. The check engine light appears every time I make a sharp turn or go over a bump in the road. I've spent around £££ with Giallo, and today it appeared again. If I switch the engine off, set the alarm, turn-off the alarm, and start the car, the check engine light is off but appears again at the next sharp turn or bump. I'm seriously going to hit the bonnet with an axe if someone doesn't help me. Please.......please.....someone help me....

rob4wd -> RE: check engine light keeps coming on. (1/10/2009 22:30:27)


it sounds as though the magnet on your accelerometer has become detached. these can be refixed (cheap) as opposed to relacing the unit (expensive). often the errant magnet can short the cct board and blow fuse 10 . there has also been one report of it causing a fire.


it is not obligatory to use full throttle on every trip. do not risk your license.on the 3200s if full throttle is not used on a trip it narrows the voltage parameters of the throttle pot slightly. eventually the band is so narrow your car feels twitchy and entertaining to park.just carry out the throttle reset procedure to reset the no throttle and full throttle limits and your good to go again.cant help with your cel you need sd.



bill -> RE: check engine light keeps coming on. (1/10/2009 23:15:36)

if the sd2/3 points to throttle body potentiometer reading errors, (and thats the best way to nail the CEL light issues) the best solution is to replace them with contact less potentiometers. I offer this service at a discount to forum members so PM me if you  are intrested. I have done this to my own car with great success. What other people offer is cleaning of the worn track or moving the wipers of the pots to a unworn part of the track or swaping the maserati throttle ECU with the volvo body (!). This however does not solve the problem long term especialy the last one as there is a 13mm diference on throttle bore!