Hi all,

I've been having running issues for a while now and after a trip to DTR they think its the ECU being faulty.

I've tried to call around 10 ECU testing companies, none of them work with the Hitachi unit.

Does anyone know of an ECU testing company that work with our ECU's?

Thanks

Hi.

SEARCH on here is good

Ducato section has quite a few repair faults threads..

You have ruled out poor connections??

Charlie

Thanks, but this is specific to the Barchetta due to its Hitachi unit. I've called numerous vendors and none can help. The crux of the issue is that the Hitachi unit on our cars are just so uncommon that most people dont have a test rig.

I found 1 company that can support it, but not the model of the ECU my car has.

Well i would be looking along the lines of:

You don't say what the issues are:

1) Check the ecu connector for corrosion, good contacts on male/female parts etc.

2) Use MultiECUScan to check and record ECU data signals/parameters and compare before issue and after issue data

I appreciate (2) above might prove tedious and time consuming but it may real/point to issues with ECU input data and not ECU output data.

The FREE MES version of MES supports the Barchetta so all you need in a cheap KKL interface device with no modifications. Depending on your vehicle's year of mfg you may need an OBDII 16 Pint to 3 Pin Adapter.

You can also with MES do Actuator tests such as: check ignition coil and injector operation.

Would it not be easier to find compatible ECU from some internet junkyard? Shouldn't cost you a fortune.

wapper said:

Would it not be easier to find compatible ECU from some internet junkyard? Shouldn't cost you a fortune.

Click to expand...

They are often Coded..

I would spend time checking connections... they fail more than ECU's


But worth discovering who DOES use HITACHI kit.. their specialist garages should be in the know regarding repair workshops

Charlie

wapper said:

Would it not be easier to find compatible ECU from some internet junkyard? Shouldn't cost you a fortune.

Click to expand...

Yes, but ......

Not 100% sure about the Barchetta (depending on year) but the ECU may be paired and coded to the key control unit (and body computer).

This would mean that a replacement ECU has to be "virginised" for it to work with the vehicles existing key/body ECUs

The reason the fault is thought so sit with the ECU is due to impossible readings coming from the temp sensor.

When the sensor is plugged in it reads an almost constant 20c, causing a large reduction in fuel going through the cylinders. This is causing my lean running and misfiring at idle/low rpm.

When the sensor is unplugged it should default to a -37c reading, which sometimes it does, and when this happens the car runs very rich but of course runs without misfiring. But sometimes the ECU is reading a temp sensor value of 20-25c.

If the ECU is reading a value from a sensor thats not connected to the ECU then the fault lies within the ECU...it would explain why the car is running so lean if it thinks the external air temp is so hot (and thus less dense, so requiring less fuel to combust).

Connections have been checked, but this weekend I'm going to remove the ECU and give it a once over as much as I can do.

I've also found 2 more companies to call today, and am speaking to Henk as he mentioned he can test the ECU.

Backup plan - and one I'd like to avoid due to the cost - is going down an Emerald ECU route.

May I suggest looking at the o2 sensor signal .
If signal is switching then the ecu is adjusting the fueling.
If o2 signal switching then even with wrong air temp reading the ecu has still been able to trim fuel .

If mixture still obviously incorrect then you may have a faulty o2 sensor that is reading incorrectly.

If you have really bad misfiring then the above is not helpful due to unburnt air air fuel entering exhaust.

try unplugging air temp sensor and looking to see if ecu goes into closed loop and o2 sensor switching when normal coolant temp reached.

Strange that a reading of 20 degrees( that would be pretty typical inlet air temp) would cause problems.

What air temp reading do you get from ecu if you short the air temp sensor contacts?

I wonder if low rpm misfire cause is not caused ecu air temp reading but lies elsewhere.

minimayhem said:

The reason the fault is thought so sit with the ECU is due to impossible readings coming from the temp sensor.

When the sensor is plugged in it reads an almost constant 20c, causing a large reduction in fuel going through the cylinders. This is causing my lean running and misfiring at idle/low rpm.

When the sensor is unplugged it should default to a -37c reading, which sometimes it does, and when this happens the car runs very rich but of course runs without misfiring. But sometimes the ECU is reading a temp sensor value of 20-25c.

If the ECU is reading a value from a sensor thats not connected to the ECU then the fault lies within the ECU...it would explain why the car is running so lean if it thinks the external air temp is so hot (and thus less dense, so requiring less fuel to combust).

Connections have been checked, but this weekend I'm going to remove the ECU and give it a once over as much as I can do.

I've also found 2 more companies to call today, and am speaking to Henk as he mentioned he can test the ECU.

Backup plan - and one I'd like to avoid due to the cost - is going down an Emerald ECU route.

Click to expand...

Most ECUs will assume default values when any input is missing, or outside parameters. This could be what you are experiencing.

When the intake temp sensor is unplugged it goes into closed loop...sometimes. It will go in/out of closed loop, all the while all other sensors (including 02) are registering normal readings (or are indicative of lean running). The temp sensor is also pulling a steady voltage as well.


I removed the ECU today and the connector that is near the brake fluid reservoir has evidence of liquid along the connector ports, and the ECU on that side has spots of fluid imprinted where the connector fits in.


A while back brake fluid sprayed over the engine bay when my brake bleeding tool depressurised due to a fault. The problem started after that. I've been chasing air leaks for about a month to no avail, so took it to DTR. They cant find an air leak and came to the conclusion it could sit within the ECU.

I'm starting to think that what I just found today is further evidence of this. I can't see why else there would be liquid on the inside of the connector, although the fact that the connector is protected by a rubber sheath discredits this.

Called the other 2 companies plus 2 more I found today, to no avail. Options now are:

1) Buying some contact cleaner and cleaning the connector male and female side. I can see the male side (ECU side) has a visible gap around the connector spokes (spikes?), if oil made its way in I will need to open the unit up. It's fully sealed, so god knows how I'm going to do that

2) Henk. Requested, no response. Does not have an ECU using the same part number as mine. Risk of buying an ECU that is wired differently to my car, and being a big waste of money.

3) Emerald. Very expensive, and confirmed today they have not worked on a Barchetta/HGT engine before. Will need a custom loom to be made, modification to the engine and potential development to work with the B's BCM.


I'll plug my laptop in and take more sensor readings when it stops to try and confirm this all, but am heavily leaning towards DTR's diagnosis.

What reading do you get with air temp sensor wires shorted together ?

Yes to cleaning connector plugs and sockets.

Correct electrical cleaner should not harm electrical components but keep the ecu vertical so any excess cleaner doesn't run into ecu if it's open to connector.


Did you find wet liquid in connector?

I'll need to check at the weekend,it's raining hard at the moment and to tomorrow.

My plan is to spray contact cleaner liberally into the ECU while holding it vertically and spraying down from the side opposite the brake fluid reservoir,so with that side facing down. That way if oil made it in, the force of the contact cleaner with push it out nearest the side the liquid entered into. I've got a can of compressed air which I'll spray after to remove debris and remaining contact cleaner.

I didn't shine a light into the connector, will check though.

So the soak failed! No change at all.

Annoyingly I cant see coolant temp on multiscanecu.

I'll check out the lambda sensor voltage tomorrow. I noticed it dripping from 0.3 to 0.2 whenever the car hunted.

Coolant temp sensor voltage was stable but shot up when disconnected. I'll get back tomorrow with more readings.

minimayhem said:

Annoyingly I cant see coolant temp on multiscanecu.
I'll get back tomorrow with more readings.

Click to expand...

Should be air and fuel temps too

minimayhem said:

So the soak failed! No change at all.

Annoyingly I cant see coolant temp on multiscanecu.

I'll check out the lambda sensor voltage tomorrow. I noticed it dripping from 0.3 to 0.2 whenever the car hunted.

Coolant temp sensor voltage was stable but shot up when disconnected. I'll get back tomorrow with more readings.

Click to expand...

What device are you using to read ecu data?
I've just been looking at my mes software for barcetta and it does not show inlet air temperature!

Before doing anything to inlet air temperature sensor post a picture so I know what you are talking about.

I've been using multi ecu scan 4.6R1 on my laptop. Just seen that I have engine temp, which I presume is coolant temp?


I also mis-read the email from DTR, they were referencing the coolant sensor temp. What they are saying is that:

- When the car has the coolant sensor connected, the voltage registered on the sensor is consistent but the temp reading is inconsistent

- When the sensor is disconnected the fan runs constantly, and the reading drops to -37, and the car runs fine. After a while the car starts to misfire and despite the sensor not being connected the ECU is reading 20 degrees.

- They checked for air leaks but found nothing substantial. They think its not an air leak due to it being an intermittent issue (although to say its always happened with me over the past month).

- They replaced the MAF, IACV, plugs and coils to no effect


What I've noticed is that if I cover half the intake, the car runs fine. So for some reason the car is injecting less fuel into the cylinders.

minimayhem said:

I've been using multi ecu scan 4.6R1 on my laptop. Just seen that I have engine temp, which I presume is coolant temp?


I also mis-read the email from DTR, they were referencing the coolant sensor temp. What they are saying is that:

- When the car has the coolant sensor connected, the voltage registered on the sensor is consistent but the temp reading is inconsistent

- When the sensor is disconnected the fan runs constantly, and the reading drops to -37, and the car runs fine. After a while the car starts to misfire and despite the sensor not being connected the ECU is reading 20 degrees.

- They checked for air leaks but found nothing substantial. They think its not an air leak due to it being an intermittent issue (although to say its always happened with me over the past month).

- They replaced the MAF, IACV, plugs and coils to no effect


What I've noticed is that if I cover half the intake, the car runs fine. So for some reason the car is injecting less fuel into the cylinders.

Click to expand...

Ok so nothing of this is intake air temperature sensor related which it looks like your car does not have or is not supported mes readings.

Engine temp in degrees c yes coolant temp.

Voltage consistent, consistent to what?

You can not assume ecu is faulty because after unplugging coolant temperature sensor the reading you get from ecu drops then a while later levels off at 20c. The reading could be what the ecu is substituting because it thinks the coolant temp sensor is faulty , that could be exactly what ecu is programmed to do.

With coolant sensor plugged in and watching mes start the car and watch the coolant temperature in degrees c.
You can even select graph.
Wait until car properly warm and thermostat opens .
What temp does coolant get to, on way to warm does coolant reading smoothly rise?

The injection system is nothing like carbs where restricting the air intake will richen the mixture .

Though it is interesting that you day covering half the inlet changes things. Do you mean covering half air filter inlet ?
Or have you removed the duct between air filter and throttle plate?