DTC Codes RE: TB & PP 3200GT AC

[tappets]

Ok, I had 5 stored codes and have got it down to 2! Can anyone tell me what code P1225 indicates (Does the workshop manual contain manufacturer specific code library? Other code is P0225 TPS sensor possibly Pedal Pot as I have slightly low 300mv on idle circuit and normal 3.1v at full pedal. My question is...............is the minimal low 300mv instead of 3500mv enough to activate CEL and prevent throttle response? Still have no throttle response at TB after reset/calibration, should TB butterfly be seen moving with ign in MAR and engine not running when pedal depressed?

Any help appreciated.........Cheers

 

[Contigo]

Yes that is too low. What you need to do is adjust the pedal rest position there are some nuts at the top of the pedal itself, imagine the pedal is traveling too far to rest, if you start the car with a slight pressure on the pedal (i.e. 350-400mv) it will start without CEL and rev Freely. Once you have this position adjust the screws so the pedal is set in this position.

 

[davy83]

yes idle should be between 0.35v and 0.6v and the full throttle should be within 2.9v to 3.6v. you need both to be within these limits. There are large bolts on the pedal that will allow you to move these positions around. And you also need to run the calibration after setting it up. If its outside the range the calibration wont work. allow a little longer for the wait times, officially idle is 2 minutes allow 2 minutes and 10 seconds, full throttle is meant to be for 5 seconds, hold it for 10-12 seconds and make sure its steady, press the pedal hard to the floor and don't let it move during the 10 second period. if either voltage changes much during the calibration it will fail, so try it a couple of time to be sure.
Good luck with it!!
Calibration procedure is car in neutral, ignition on, engine not running. first idle leave for 2 minutes 10 seconds, then ignition off. same deal car in neutral press pedal to full throttle for 12 seconds and then ignition off. repeat!

 

[tappets]

Ok thanks guy's will try this procedure!

Cheers, T

yes idle should be between 0.35v and 0.6v and the full throttle should be within 2.9v to 3.6v. you need both to be within these limits. There are large bolts on the pedal that will allow you to move these positions around. And you also need to run the calibration after setting it up. If its outside the range the calibration wont work. allow a little longer for the wait times, officially idle is 2 minutes allow 2 minutes and 10 seconds, full throttle is meant to be for 5 seconds, hold it for 10-12 seconds and make sure its steady, press the pedal hard to the floor and don't let it move during the 10 second period. if either voltage changes much during the calibration it will fail, so try it a couple of time to be sure.
Good luck with it!!
Calibration procedure is car in neutral, ignition on, engine not running. first idle leave for 2 minutes 10 seconds, then ignition off. same deal car in neutral press pedal to full throttle for 12 seconds and then ignition off. repeat!

 

[Contigo]

yes idle should be between 0.35v and 0.6v and the full throttle should be within 2.9v to 3.6v. you need both to be within these limits. There are large bolts on the pedal that will allow you to move these positions around. And you also need to run the calibration after setting it up. If its outside the range the calibration wont work. allow a little longer for the wait times, officially idle is 2 minutes allow 2 minutes and 10 seconds, full throttle is meant to be for 5 seconds, hold it for 10-12 seconds and make sure its steady, press the pedal hard to the floor and don't let it move during the 10 second period. if either voltage changes much during the calibration it will fail, so try it a couple of time to be sure.
Good luck with it!!
Calibration procedure is car in neutral, ignition on, engine not running. first idle leave for 2 minutes 10 seconds, then ignition off. same deal car in neutral press pedal to full throttle for 12 seconds and then ignition off. repeat!

It can take up to half an hour or even longer if those values fluctuate.

 

[tappets]

Phil............are you saying 30min of trying to calibrate using above advice? I have the correct voltage range now at both idle & full pedal but still no throttle response. I've done the calibration 4 times with zero results??????

I have one of Davy's P pots in the way as I still suspect it's the culprit even with correct voltage range!

It can take up to half an hour or even longer if those values fluctuate.

 

[davy83]

have you measured both of the pedal sensor outputs? there are two of them and they need to be exactly the same. I reckon anything more than 15mV difference is a fail, so if you measure 0.340 on one and measure 0.355 on the other it will fail. This is the biggest reason they fail, and why joining the two wires together can often make it work. The new one on its way to you is electronically matched and should be less than 5mV difference always. It would perhaps allow you to understand why its not working?

 

[davy83]

sorry that was a bad example i should have said if one is .370 and the other is 0.386 it will fail and indeed if the second one is less than .385 it should be ok. The example above of course is below the minimum, sorry.

 

[Contigo]

For the sake of the test do what most people do when the pedal is on its way out, it will prove once and for all that it is the pedal. Bridge the white and yellow cables together with a short block or solder. This will take an average of the two circuits if there is too much of a discrepancy and at least give you some pedal control.

 

[tappets]

Yes thanks chaps........the wire mod was done some time ago when PP began to give trouble. Can anyone direct me to the TB correct parameters and OBD diagnostic code list as I have 2............P1225 & P0225? P1225 isn't listed in generic code list? I do have a new Davy PP on its way so I'm hoping its the PP!

The TB does the click & set at Ign on.............but nil pedal response after recalibration! Car starts and idles but nil throttle.

For the sake of the test do what most people do when the pedal is on its way out, it will prove once and for all that it is the pedal. Bridge the white and yellow cables together with a short block or solder. This will take an average of the two circuits if there is too much of a discrepancy and at least give you some pedal control.

 

[davy83]

Just for clarity the bare wires in that picture need to be connected together, like all four of them connected together for that to work.

 

[CatmanV2]

P1225: Closed throttle position learning value is excessively low.

C

 

[davy83]

Now does that apply to the calibration of the pedal sensor or the position of the butterfly in the TB?

P1225: Closed throttle position learning value is excessively low.

C

 

[CatmanV2]

Now does that apply to the calibration of the pedal sensor or the position of the butterfly in the TB?

Yeah, that's the million dollar question isn't it!

C

 

[Contigo]

Now does that apply to the calibration of the pedal sensor or the position of the butterfly in the TB?

It doesn't apply to anything it is a generic OBD code!

 

[Contigo]

Yes thanks chaps........the wire mod was done some time ago when PP began to give trouble. .

Then your pedal is now totally dead.

 

[Danny]

It doesn't apply to anything it is a generic OBD code!

Contigo, can you please clarify this comment? It is the first time I read this.

 

[bill]

With the ignition on and the engine not running, the throttlebody should make a buzzing noise after the click and set. The butterfly does not always move when the pedal is depressed, under these circumstances. No buzz, no good throttlebody....

Yes thanks chaps........the wire mod was done some time ago when PP began to give trouble. Can anyone direct me to the TB correct parameters and OBD diagnostic code list as I have 2............P1225 & P0225? P1225 isn't listed in generic code list? I do have a new Davy PP on its way so I'm hoping its the PP!

The TB does the click & set at Ign on.............but nil pedal response after recalibration! Car starts and idles but nil throttle.

 

[Contigo]

Unidiag is somehow converting them to OBD specific codes as 99% of these cars are pre OBD2. To really understand what the problems are with the DBW you need it connected to a SD2/3 machine is what I am trying to say.

 

[urquattrogus]

Basically they use standard ones for most manufacturers:

http://www.launchtech.co.uk/dtc-codes-list/

OBD and its variants is supposed to be some sort of generic standard, and it was made mandatory in 2001 for all EU cars, but existed before that too.

As I understand it the car might show P1225 on your ODB reader, but to really tell what it is actually is you need an SD2/3 Maserati system, as it's manufacturer specific application of that code.

But over time we have come to know what P1225 means for the 3200.

Made worse by the fact that it seems even the best ODB readers don't have a list of Maserati codes and or compatibility. I have a good Autel unit, and can use that do so loads on my 2013 BMW and countless others, but I contacted them and they don't support Maserati, so I just use it to read a generic ODB code.