Technical FIAT PUNTO 188 1.2 16V ECU (0261206546) PINOUT DIAGRAM

[Mohato]

Good day everyone, I am looking for the ECU wiring diagram for my Fiat punto 188 1.2 16V.
I have a donor engine I want to build and test on the test stand and my wiring loom isn't looking good.
Kindly assist.
Thanks

 

[Fiat1271300]

Hello, I think I have the same symptoms, I changed fuel pump with original fiat, manifold pressure sensor with Fiat original, throttle body new, Fiat original spark plugs, new 10mm silicone plug leads, wateR temperature sensor, replacement fuel injectors from known good car working, brand new catalytic converter, Bissau centre section exhaust, Bosch crankshaft sensor, new battery and alternator, and it still misfires, rough idling, erratic running, doesn’t start first time anymore. I have borrowed a icarsoft scanner and no codes found and not a clue what’s wrong. Anybody any ideas?

 

[Fiat1271300]

Does anybody know where I can find the pin outs for the ecu for the Fiat Punto 1.2, 16v ELX.

 

[judderbar]

Does anybody know where I can find the pin outs for the ecu for the Fiat Punto 1.2, 16v ELX.

its in the punto downloads uploaded by me

 

[Fiat1271300]

I’m new to this and don’t know how to see where the download upload is

 

[Fiat1271300]

The ecu pin out download picture differs from my eco, see attached for my Punto mk2

 

[judderbar]

how different is it though? They are both bosch ME73H4

 

[Fiat1271300]

Hello, thank you very much for supplying the information about the ecu for punto mk2. 1.2,16v. I am trying to understand why my punto seems to run in limp mode. It smells in the car when it runs badly like burning, either wire or plastic but I can’t trace it. The problem starts when I turn into a corner weirdly. I am looking at it tomorrow.

 

[Fiat1271300]

Is there a diagram explaining what all the relays and fuses do in the box in the engine compartment for Fiat Punto 1.2, 16v ELX, I can check if they are working to help diagnose the problem I am having

 

[judderbar]

The fuse box diagram is part of the underside of the fusebox cover.

https://www.hy2japan.com/product-page/fuse-box-fiat-punto-elx-2003-gf-188a5

 

[mcf1lmnfs]

Hello, thank you very much for supplying the information about the ecu for punto mk2. 1.2,16v. I am trying to understand why my punto seems to run in limp mode. It smells in the car when it runs badly like burning, either wire or plastic but I can’t trace it. The problem starts when I turn into a corner weirdly. I am looking at it tomorrow.

If it smells in the cabin like burned plastic this is usually because one connector is burning due to bad connection and therefor increased electrical resistance. The connector that you should check 1st is a heating resistor connector. You know you have ventelation in this car and you can turn it on 0 or 1 or 2 or 3 or 4. When you have 0 or 4 there is everything okay because there is no electrical current trough this resistor ( 0 becase its not running at all, 4 the current bypasses this resistor). Usually the biggest problem is 3, becase there is largest current trough this resistor and the connector on this pin used for this gets coroded 1st. Shortlly after this, if you still use the ventilation on number 3, the whole connector is getting melted and burned, even if you buy the new heating resistor, you still have bad connector on other side, so thing i recommend here is to cut this connector away, throw it in garbage, and connect the wires without connector, preferly by good soldering, thick solder connections and over it add protective tape or shrink wrap. This connector can be found where passenger knees usually are. The resistor is sticking inside of ventialation chamber because inside there is moving air and it uses this air for cooling itself down. This is also why you have to be careful that your cabin filter is not clogged. So as said the main body of this resistance is inside this ventilation chamber, but the connector we are talking about is sticking outside, so, down to the foot of the passanger. And the other part of connector - the one with wires comes to it. So just take this conncetor of and you will immediatly see if it is in good shape or is everything here burned. Anyway I hope i guessed your problem - if its not this, remember that only very high current can cause such heating and you only need to check these. Meaning, there should be nothing wrong with ECU because there are all the lines with very little current. In this car, until now I only found this trouble that i am mentioning above. Other lines i can think to check are red cable from car battery to the fuse box, is it in good condition, does it heat up when you have a car in idle? Main ground connection from the car battery down to the gearbox? - you have to remove the car battery and the box for carbattery to get down to the connection to the gearbox.

About missfiring, remove the passanger front wheel, remove the inned plastic guard/fender, remove the guard for serpentine belt, take the serpentine belt off (you take it off by trying to screw bolt on serpentine tensioner even more - bolt 13mm head), remove 3 scews 13mm from the serpentine pulley (when you will be puttin it back notice a little pin here - it can only be turned this one direction), support the enginge from the bottom - you can putt some wood under the oil can, and lift the engine 1cm, undo the all 6 nuts at the top for the engine holder on passenger side (this is under the hood, near where big spring nut is at top), now next step is a bit tricky because there is not much room here, if you need a bit more room, you can lift the engine up from bellow a bit more, 5 or 10cm, so you need to undu 6 horizontal screws that are in the bottom part of the engine holder, they are all the same - 13mm head. Then undo plastic cap of the timing belt - one screw at top 13, one screw towards front of the car 10, and one screw in middle of the bottom half 10, remove the cap for timing belt, check timing tensioner, does is still hold? At the bottom you have induction sensor that is reading teeth at the previously removed serpentine pulley. Make sure there is no metalic, iron dirt on this sensor - so wipe it a little, and also check your pulley if it has no metalic, iron, ferite dirt or maybe even broken one tooth. The next thing is, this sensor is sending this date trough wires that goes trough the plastict cap of the timing belt, please check if these wires are in good conndition. At the beginning of engine lifetime there is usually some protection around these wires, but usually withing 10years it degrades, so add some protection to these wires back. After checking all this and assemblying it back, I expect the motor to have 0 missfires. If you find the tensioner a bit loose it is possible that the timing is off for a tooth. Its possible to align it back with some tools, or even with just a picture of the tool, so i wont describe this until you say its needed. I never had a problem of it being missaligned for a tooth, but i had a problem that i was drilling something above this motor and one sharpenel from drilling fell down right in between that induction sensor and the serpentine pulley. So i believe the ECU is giving spark timing according to this lower induction sensor. But you should be aware that there exists one more. At the top of this engine, between 3th and 4th spark plug there is also one induction sensor for inlet camshaft, that also serves for some timing corrections for sparks and injectors, but it plays smaller part, if you have such large missfires there is either a problem with the one at the bottom or with you even have a missalgiment in timing belt. If you get until here and still with a problem, you can try replace both of the sensors.

What do you mean by "I have borrowed a icarsoft scanner and no codes found and not a clue what’s wrong". On this car every missfire gets recorded, and when reading errors, you should see missfire cylinder 1, or 2 or 3 or 4, or combiantion of more of them.

you mentioned you changed many parts already, did you also do the ignition coil ?
Did you remove throttle valve and clean it inside where air is passing trough ?
your catalyitic converter, does it have heat shield in front of itself? These cars have aluminium heat shield and on holes where it is attached it usually corodes and the shield falls away, but this heat shield is a crictical component for this engine - only if the catalytic converter is properly heated 02 sensors are working correctly.
How do you know your car is in a limb mode?
Do you have your engine light on? I assume you should - but then why are you saying you see no error codes - get the error codes with obd diagnostic tool and report more about your problem so we can solve it. If you dont know how or something, we can work on this 1st..

Please come back with more info about problem or with info how you solved it and what it was.

 

[Fiat1271300]

If it smells in the cabin like burned plastic this is usually because one connector is burning due to bad connection and therefor increased electrical resistance. The connector that you should check 1st is a heating resistor connector. You know you have ventelation in this car and you can turn it on 0 or 1 or 2 or 3 or 4. When you have 0 or 4 there is everything okay because there is no electrical current trough this resistor ( 0 becase its not running at all, 4 the current bypasses this resistor). Usually the biggest problem is 3, becase there is largest current trough this resistor and the connector on this pin used for this gets coroded 1st. Shortlly after this, if you still use the ventilation on number 3, the whole connector is getting melted and burned, even if you buy the new heating resistor, you still have bad connector on other side, so thing i recommend here is to cut this connector away, throw it in garbage, and connect the wires without connector, preferly by good soldering, thick solder connections and over it add protective tape or shrink wrap. This connector can be found where passenger knees usually are. The resistor is sticking inside of ventialation chamber because inside there is moving air and it uses this air for cooling itself down. This is also why you have to be careful that your cabin filter is not clogged. So as said the main body of this resistance is inside this ventilation chamber, but the connector we are talking about is sticking outside, so, down to the foot of the passanger. And the other part of connector - the one with wires comes to it. So just take this conncetor of and you will immediatly see if it is in good shape or is everything here burned. Anyway I hope i guessed your problem - if its not this, remember that only very high current can cause such heating and you only need to check these. Meaning, there should be nothing wrong with ECU because there are all the lines with very little current. In this car, until now I only found this trouble that i am mentioning above. Other lines i can think to check are red cable from car battery to the fuse box, is it in good condition, does it heat up when you have a car in idle? Main ground connection from the car battery down to the gearbox? - you have to remove the car battery and the box for carbattery to get down to the connection to the gearbox.

About missfiring, remove the passanger front wheel, remove the inned plastic guard/fender, remove the guard for serpentine belt, take the serpentine belt off (you take it off by trying to screw bolt on serpentine tensioner even more - bolt 13mm head), remove 3 scews 13mm from the serpentine pulley (when you will be puttin it back notice a little pin here - it can only be turned this one direction), support the enginge from the bottom - you can putt some wood under the oil can, and lift the engine 1cm, undo the all 6 nuts at the top for the engine holder on passenger side (this is under the hood, near where big spring nut is at top), now next step is a bit tricky because there is not much room here, if you need a bit more room, you can lift the engine up from bellow a bit more, 5 or 10cm, so you need to undu 6 horizontal screws that are in the bottom part of the engine holder, they are all the same - 13mm head. Then undo plastic cap of the timing belt - one screw at top 13, one screw towards front of the car 10, and one screw in middle of the bottom half 10, remove the cap for timing belt, check timing tensioner, does is still hold? At the bottom you have induction sensor that is reading teeth at the previously removed serpentine pulley. Make sure there is no metalic, iron dirt on this sensor - so wipe it a little, and also check your pulley if it has no metalic, iron, ferite dirt or maybe even broken one tooth. The next thing is, this sensor is sending this date trough wires that goes trough the plastict cap of the timing belt, please check if these wires are in good conndition. At the beginning of engine lifetime there is usually some protection around these wires, but usually withing 10years it degrades, so add some protection to these wires back. After checking all this and assemblying it back, I expect the motor to have 0 missfires. If you find the tensioner a bit loose it is possible that the timing is off for a tooth. Its possible to align it back with some tools, or even with just a picture of the tool, so i wont describe this until you say its needed. I never had a problem of it being missaligned for a tooth, but i had a problem that i was drilling something above this motor and one sharpenel from drilling fell down right in between that induction sensor and the serpentine pulley. So i believe the ECU is giving spark timing according to this lower induction sensor. But you should be aware that there exists one more. At the top of this engine, between 3th and 4th spark plug there is also one induction sensor for inlet camshaft, that also serves for some timing corrections for sparks and injectors, but it plays smaller part, if you have such large missfires there is either a problem with the one at the bottom or with you even have a missalgiment in timing belt. If you get until here and still with a problem, you can try replace both of the sensors.

What do you mean by "I have borrowed a icarsoft scanner and no codes found and not a clue what’s wrong". On this car every missfire gets recorded, and when reading errors, you should see missfire cylinder 1, or 2 or 3 or 4, or combiantion of more of them.

you mentioned you changed many parts already, did you also do the ignition coil ?
Did you remove throttle valve and clean it inside where air is passing trough ?
your catalyitic converter, does it have heat shield in front of itself? These cars have aluminium heat shield and on holes where it is attached it usually corodes and the shield falls away, but this heat shield is a crictical component for this engine - only if the catalytic converter is properly heated 02 sensors are working correctly.
How do you know your car is in a limb mode?
Do you have your engine light on? I assume you should - but then why are you saying you see no error codes - get the error codes with obd diagnostic tool and report more about your problem so we can solve it. If you dont know how or something, we can work on this 1st..

Please come back with more info about problem or with info how you solved it and what it was.

Hello, thank you for your detailed reply, I have bought the Multiecuscan software and FIAT ALFA OBD DIAGNOSTIC LEAD SWITCH FOR USE WITH MultiECUScan , this reported lambda P0130 error. I have ordered a new Bosch sensor and will get it Saturday. I will check the heater resistor for problems, I assumed the electrical smell was from the engine but may have been a coincidence. I hope the lambda sensor will cure the problem. What seems to happen is when I try to accelerate the engine refuses to accelerate smoothly, it hesitates, misfires and will eventually stop. I will keep you updated.

 

[mcf1lmnfs]

This lambda error reminds also to check do you have the aluminium shield attached in front of catalytic converter? On the exhaust manifold?
If your shield is missing or if it has some holes in middle Its possible that lambda is ok, and that this catalyizator was running on to low temp for long time - this leads to carbon building inside and then the car gets weak and the engine light is constantly on, reporting lambda errors.
I advise to patch the shield if broken with some aluminium sheet pieces and using aluminium rivets. After this get some zinc plated nuts bolts, big washers. Make holes at places in exhaust manifold where its intendent for them. Its good to use zinc plated bolts nuts and washers, because there is less corozion then.. after this being properly attached we have to get the build up carboon out of the catalytic converter, you this by going on s drive with a car, and out the car under as high load as possible with goal to heat the exhaust, like driving 140km/h possibly uphill, and in worse cases it can take up to 3h to get completly rid of the carbon.

In previous reply i mentioned this, but i refered to lambda sensors as 02 sensors, this is the same thing, you have one above and one below cstalyc converter.

If you will be removing this lambdas, the bottom one usually goes out very hard, it helps to heat the exhaust pipe using s small torch flame - be careful not to burn axle boots. Before puting new bottom one in, if you have at hand the correct tap to clean the threads, this would be nice. If i remember correctly i think the thread is M18x1.5.
Btw, both upper and lower lambdas are exactly the same, same thread, same build, same connector.

 

[Fiat1271300]

Hello, I really appreciate your feedback, expertise and experience. I have owned this car for 17 years, when I bought it it had 45,000 miles now it has done 175,983 miles. This car has been very reliable in all that time with regular service and maintenance. So I haven’t done bad. I have always done the work myself for mot’s. This is the first time I’ve had to plug the car to a computer to help diagnose a problem. I will usually check obvious things first then go from there. I also am going to check the inertia switch just for peace of mind. I understand what you say about the catalytic converter heat shroud, mine needs a little repair and I will do that like you mentioned with pop rivets. The catalytic converter was replaced on the last mot because the original one was beyond repair, I should have replaced the lambda/ O2 sensor at the same time.
Where are you in the world? Regards Nick

 

[mcf1lmnfs]

Hello, I really appreciate your feedback, expertise and experience. I have owned this car for 17 years, when I bought it it had 45,000 miles now it has done 175,983 miles. This car has been very reliable in all that time with regular service and maintenance. So I haven’t done bad. I have always done the work myself for mot’s. This is the first time I’ve had to plug the car to a computer to help diagnose a problem. I will usually check obvious things first then go from there. I also am going to check the inertia switch just for peace of mind. I understand what you say about the catalytic converter heat shroud, mine needs a little repair and I will do that like you mentioned with pop rivets. The catalytic converter was replaced on the last mot because the original one was beyond repair, I should have replaced the lambda/ O2 sensor at the same time.
Where are you in the world? Regards Nick

No problem, always happy to help if i can. I am from Slovenia, country next to Italy. Punto is quite popular here.

 

[Fiat1271300]

Hello, you were correct about the plug on the heater wires. I checked my inertia switch to make sure it hadn’t tripped, it hadn’t because this would possibly explain why fuel was not being supplied to the engine. I will get the lambda sensor later today so hopefully it will resolve my problem the software is highlighting.

 

[Fiat1271300]

I have fitted the new lambda/ O2 sensor and a new set of Champion spark plugs, also crankshaft timing sensor. Brand new injectors/ rail and wiring harness. Runs a lot smoother at idle. Starting is not good, takes a lot to start it. I noticed when I pulled the petrol pipe off the fuel rail not much fuel came out, no pressure. I haven’t got a fuel pressure gauge tester yet. I did replace the fuel pump in the tank with a Bosch one correct for this model 16v etc so shouldn’t doubt the pump, maybe?. But when I spray some carb cleaner in the intake and turn the ignition over starts straight up first time, and idles. The Multiecuscan scan software has corrected the lambda fault it flagged up before, so I know that is all good now. I am wondering if the evap solenoid valve in the intake would have an effect or not to the running of the engine? I am going to check the petrol feed pipe from the injector rail to the petrol tank tomorrow, just in case there is a problem with it.
I have ordered a spare throttle pedal just in case.

 

[mcf1lmnfs]

Throttele pedal should be ok. It has two potentiometers inside, so the ecu is checking if both signals match, and if not it tells you an error about it.

About fuel pump, each time you go with your key from off into MAR you should hear it working for a around 2 seconds. Do you? And you can try going multiple times from off to mar again and again before starting the engine. Does it start better like this? Then there is some problem with pump or fuel lines.

 

[mcf1lmnfs]

To fix this resistor connector i usually drill holes trough black plastic (red marks on picture) And i cut off the connector on wires. Then i bring wires trough these drilled holes. And i solder all of them straight on the resistor pins (marked by yellow dots on picture).
But multiple possible repairs are here, so choose the one you feel best with... Its possible to buy new wire connector and also this heat resistor if you want to have it really nice. I usually do my version because these connectors eventually get this issue and i feel that if i solder this good it is permament solution. But you should know there are people who say that in car you should never use soldering because constant vibrations can make soldered things come apart - thats why many wires are crimped inside a car instead of soldered.

 

[mcf1lmnfs]

Maybe check in what condition is the fuel filter. Hmm, if my memory serves me correct it is above front passanger wheel, above the plastic fender which has many many annoying philips screws.