Intermittent CEL

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Pierre D

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The CEL warning light comes on intermittently on my 3200 GT, for a few weeks. However, I've noticed no error code with my OBD scanner tool, since I've made new solders on the pedal pot wires and replaced the TB for a contactless one. The other thing is that I don't have any limp mode. Any idea of the problem ? I think it can be linked to the connector under passenger's side carpet but I don't know which connector I have to suppress so as to solder the wires. Is it this big blue one ? CAM01058.jpg
 
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Contigo

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The CEL can come on for a multitude of reasons Pierre. The main ones or should I say most common ones are related to the Drive By Wire system (DBW) and include any problems with the Throttle Body Potentiometers, the Bosch Pedal Potentiometer and the cabling at both end of that connector and at the ECU. The cables you show above are not linked to the DBW circuit so I am not sure what you have in mind. If there is a problem with the Throttle Body, pedal pot or the wiring you will get a Check Engine light AND limp mode where usually power is restricted to below 3K rpm.

The other things which can cause CEL are

1) Knock sensors
2) Pierburg valve and MAP sensors
3) Brake Pedal Switch
4) O2 sensors

There are three or four different types of limp mode too so even though the CEL is on it might be in a lower less power reduced limp mode to the most severe or lowest level one.

Are you sure there are no codes stored? What software do you use and what type of connector do you have under the dash?
 
outrun

outrun

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The 3200 is also very sensitive to battery voltage. Its worth buying a new battery even if you don't think that yours has any issue. Or at the very least use a Ctek or similar battery conditioner every time you leave the car for more than 2 or 3 days.
 
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Pierre D

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Contigo said:
The cables you show above are not linked to the DBW circuit so I am not sure what you have in mind.
Click to expand...
I've read that most of the electric problems on 3200 GT are coming from the bad connections on passenger side, below the carpet but that you can supress this source of problems.
Contigo said:
Are you sure there are no codes stored? What software do you use and what type of connector do you have under the dash?
Click to expand...
I have a 0BD2 connector under the dash and I use 3 software : EOBD facile (in french), Torque and DashConverter. None of them give codes. I have even been to an independant Maserati dealer who has the SD2 diagnostic tool and it was the same result.
 
ledlights

ledlights

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Hi Pierre,

Could you tell me what the year of manufacture is for your car?

Thanks,

Steve
 
jluis

jluis

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A CEL light coming on and no codes stored to be read by the SD2?
This can be a long shot but is it possible that the problem is on your cluster/wiring causing the light to come on even if there is nothing wrong with the car?
I don't know about the 3200 but newer cars usually store codes that triggered CELs even after the light is out.
 
Contigo

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Yes the binnacle could be defective for sure.

And the wires you talk about are the ground connections to the ECU form the same loom as the pedal pot.
 
ledlights

ledlights

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I wonder whether the reason you're not seeing any codes is that your code reader isn't compatible with your ECU.

Your car might not be EOBD compatible. Does it have an OBD style multi plug or a 3 pin ISO connector? There was also a change over between the ECUs in 2000 that means that there was a period when the cars had a OBD plug but an early KKL interface protocol. If so, have a look at the guide I put together on the Unidiag which might help you read the codes.

Hope this helps,

Steve
 
ledlights

ledlights

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Okay have a look at his thread:

http://www.sportsmaserati.com/showthread.php/7370-Reading-error-codes-on-an-early-3200GT

I think it's possible that the reason you're not seeing any error codes is that your OBD reader isn't compatible with the KKL protocol on the early 3200s (assuming of course that you've got one of these but based on your car's age it's likely). If you follow the thread above, you may have some success.

On the cause issue - my car has an intermittent CEL which goes away again and doesn't lead to limp home mode when a lambda sensor is starting to fail. The only way to tell is by getting the fault codes.

Hope this helps,

Steve
 
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Pierre D

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Thank U Steve, I've installed the unidiag software but I can not connect my ECU on it. My ELM327 interface is a bluetooth one, so that's perhaps the reason of this failure.
 
ledlights

ledlights

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Pierre, it sounds to me like you'll need to get a V A G . C O M interface to get this to work. It uses a different handshake protocol amongst other things. Have a look at the guide and get hold of a cable that uses the COM port chips manufactured by FTDI (http://www.ftdichip.com/FTDrivers.htm) - this is important because the cheaper Chinese chips aren't compatible with the unidiag software. If you follow the posts on the thread you'll see a lot of people had gone through this before.

Good luck,

Steve
 
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Pierre D

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I've checked my ECU. However the car was manufactured on october 2000, this ECU was produced on 22/01/2001 and there is a sticker with the mention "Phase 3 EOBD aggiornatta". I think it is linked to the fact the engine was replaced under warranty in 2002.
 
Contigo

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You might need Galleto 1260 software to read. You also need the KKLine *** com type cable from Ebay
 
jluis

jluis

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Since you already said that the SD2 reader also did not found any stored codes it should be fair to assume that there is no stored code inside the ECU.
Regarding the ECU I remember seeing a thread here or on some other maserati forum with the part numbers for the ECU in both EOBD and non EOBD version.
I believe yours is EOBD and if you can use the torque app on android with an ELM327 adapter and read the live data from the engine then it's EOBD for sure.

Did you ever notice when the light comes and goes if it turns on solid for a while and then disappears after a while or is it fading in and out?
I ask because usually ground problems make the lights fade in and out with the car vibration, heat and moisture.
 
ledlights

ledlights

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Okay, you've got an EOBD ECU after the engine change then. The V A G lead won't help and you should be able to use your ELM.

Although I've had my car since 2006, I haven't ever had a CEL without stored codes so I can't think what could be the problem here. As jluis says above, it could be a moisture problem but it's not something I've experienced or heard of with on 3200s.
 
jluis

jluis

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To know for sure, force a CEL.
Disconnect a sensor that is easily accessible and that is known to throw CEL's, Maybe someone can suggest an easy victim :)
After the CEL lights up, check for the presence of a code with your reader.
If you see it, at least you will know a code has been raised.

Then reconnect the sensor, wait for CEL to clear and check on your reader for the presence of a stored code.

I did this on a Volvo when I was testing an ELM327 reader and there are 2 distinct code section you can access.
Presently active codes and stored codes. This should also be true for the 3200 with EOBD
 
Contigo

Contigo

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Simple, just disconnect the Pedal potentiometer and start the car, it will fire up in limp mode and the fault code will be p0225 or p0226.
 
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