Technical Bizarre repeat problems with Fuel Injection Warning sign

Currently reading:
Technical Bizarre repeat problems with Fuel Injection Warning sign

Joined
Dec 29, 2017
Messages
57
Points
16
Hi

I am new to the forum and way out of my depth when trying to analyse the deeper issue with my Fiat Punto Mark2 2004, which has had one previous owner and done 65000 miles. A good purchase or so I thought 8 months ago. All ownership checks were done and it was fine. One previous lady owner.

Only issue with it was on idle, at a standstill, it would keep dropping revs for a split second then pick up again, but generally the engine sounded lovely and on the motorway it would purr on 80mph. Also, a minor issue ongoing round right-hand bends, it brief knocking sound from the rear left hand side comprising 3-4 knocks would happen, it has always been like that since I got it, but I thought it was just the exhaust knocking. As it has not worsened I have ignored it - perhaps unwisely? Sometimes when I look at the car, which is in nice condition, from the rear it looks as if the left-hand side is fractionally higher than the right-hand side (not due to tyre pressure). Not sure that is relevant at all.

Anyway, my problems started with the "POWER STEERING FAILURE DASHBOARD WARNING LIGHT" coming on and off. Sometimes there is no sign of it for weeks, but it seems to come on when I either have other people in the car, or when I go up and down steep multi-storey ramps, as though it is linked to suspension sensors almost? The car has always handled well when this light is on or off, and when I book it in the garage they can find no fault as it typically didn't come on when it was in. It still comes on and off, 90% of the time off, but again when on multi-storey car parks or carrying luggage or people, it tends to come on. Not sure why that is? I have never felt a decline in power steering at any point I would add, even when the light is on. Sometimes it stays on for a day or two continuously, but then not again for weeks on end.

Secondly, and more seriously, I have had problems with the INJECTION SYSTEM FAULT DASHBOARD WARNING LIGHT, which has come on 2-3 times now (NEVER FLASHING THOUGH).

First time I had it booked in for the garage, they diagnosed it and said it needed a new Catalytic Converter and gaskets. So they fitted that, cost me £160.

A month or two later the same warning light came on, and I paid £50 for what I think reads "1 x no.2 lamba, and cival(?) codes". (I can't read the word "cival" as its just a scribble and hence it could be any word).

But then two weeks ago, I was driving home after an 80 mile journey when suddenly a mile from home the temperature gauge all of a sudden dropped to zero and the same old "Injection System Fault Dashboard warning light" came on. The engine fan came on although it wasn't needed as I hadn't been standing still in traffic at all. I had it in the garage again, they diagnosed it and said it needed a new Coolant temperature sensor costing £80.

All was fine, but then yesterday, I was making exactly the same journey as previously, and at exactly the same point, a mile from home the same happened again, the temperature gauge suddenly dropped to zero and the fan came on, as well as the "Injection System Fault Dashboard Warning light". I have just been out to the car and the warning is still on when I put ignition on. Could it be weather related, it is still very cold outside?

I thought it was unusual for this to happen at exactly the same point in the journey, at both points about two miles after going over a sharp brow of a hill, which drops quickly. So this occurred twice. I mention this hill as again these warning lights in some way seem to be affected by going over hills/ multi-storey car parks/ extra weight in the car.

I know they are two different warning lights, but I thought it might just be relevant that both possibly seem to be caused by this. Could the whole issue be something to do with suspension, or the knocking sound? Probably not but worth highlighting my observations.

Any help with these warning lights and the causes would be greatly appreciated, I'm just out of my depth and although I trust my garage totally, inevitably they are not Fiat specialists. They can check the diagnosing engine management system I guess, how accurate is that though?
 
Last edited:
Three things.
Steering light.
When the light comes on, does the steering go heavy in either direction?
The steering has a high current draw, and will get upset if battery voltage is lower than expected. These symptoms are often the first sign of a failing battery. As the fault is intermittent and has not stored steering specific codes, a new battery is probably needed sometime soon.
Or not.

Check, carefully, the cable from the negative battery terminal, all the way along its length, to its fixing on the gearbox and the car body.
Check all three connection points for corrosion, ensure clean and tight. If possible, remove the cable and flex it a bit to feel along its length for any breakages inside the insulation. These have been known to corrode internally, creating breaks, or intermittent breaks. A new cable may well fix all your electrical issues. Failure over bumps may well point at this cable.

Engine management light.
The last code you reported related to the oxygen sensor. Has this been replaced?
Temp gauge dropping could be the temp sensor failing, or a connection issue, or the thermostat sticking open. The main cable as described above might be the cure.
To check the thermostat, start engine from cold and feel the top hose, from the thermostat to the radiator. It will get warm gently, but then suddenly as the thermostat opens. If it just gets warm gently, and never hot, the stat is stuck open.
Might have to wait for the temp drop, then open bonnet and check the top hose.

Suspension knocks.
Don't ignore this.
You need to check the suspension mountings. Compare the two sides. A failing mounting will only get worse.
Also check the dampers and their bushes.
 
Wow!!

Thank so much Bill for going to such trouble and time in responding.

I think I'll print it off for my garage, who are a very good garage to be fair. I'm really not a technical person and most of these checks are beyond my knowledge (although I'm sure they are fundamentally straightforward). I'll see what I can check myself when it warms up, but will probably have to ask the garage to make these checks.

Regards the power-steering, I've never noticed any drop at all in the steering, even when the light comes on, its exactly the same (just as light).

I always seem to have one lightbulb out too, whenever I replace a bulb, another one goes, as though there isn't enough power to charge all of them. Its my rear reversing light at present that is out, so I've left it at that.

Great advice regards the engine warning light, and the knocking sound, I'll get that checked out too.

Thank you so much Bill.

ADDENDA - its warmed up a bit, I've just been out to take some stuff to the tip, and the temperature gauge started working again, and then after a bit the "engine warning light" went off.

So, it does seem to be related to either the weather (very cold weather) OR whether I drive with weight in the car, and where I drive.

But at least it is now working again. I think it suggests something with that cable you mentioned.
 
Last edited:
New development - though I will be booking car in for garage on 2nd January, today the engine warning light came on again with no warning, but car was running fine.

Then tonight, I gave a lift to family, as soon as someone got in front seat the power steering warning light briefly came on and then went off, but more concerning without warning my windscreen wipers suddenly stopped working. Whatever position I put them in, there is no response/ no movement at all.

So many electrical issues, would that further suggest that the problem lies with the cable from the negative battery terminal to its fixing on the gearbox and car body?
 
By MK2B also showed these symptoms, have cured the power stirring, and wiper but ecu warning light have not.

On the ecu warning light i replaced the sensor, but the problem did not go. It seems to be related in my case with long journey more then 1 hour motorway at steady speeds economical driving and low temperature outside (sub 8 C). Once the condition are like this and the temperature gauge goes below 1/4 then suddenly drops to zero. If it stays at zero for more then 5 seconds the engine management light comes on and so does the fan. I have disconnected the fan as if it comes on it will keep the engine cold and make the problem worse.

This may be related to a head gasket problem which I am expecting to fail in the near future, but I am suspecting the ECU has got a problem. But as there seem not the be any adverse issues with the running of the car I can live with this for the moment. The ecu light will go off after 3 starts if the ecu does not register any further errors.

The wipers you should check if the motor is working, i.e. there is noise when you turn them on. If yes, the the linkages gone which is a common problem but unrelated to the above.

When I get the power steering light I do lose power assistance so the steering goes heavy. The wiring loom between the power steering ecu and motor is suspect on this car. Disconnecting the loom and cleaning the contacts and refit loom fixes problem usually. Avoid city mode and sudden steering movements when stationary.
 
Very interesting that you are having similar issues - exactly the same issues with my temperature gauge, only after an hours long, good driving, and in cold weather only - it suddenly drops and the fan comes on unnecessarily.

So far I've had new catalytic converter, new Lamba codes and gasket, new sensor, due the Engine warning light coming on (fuel injection system warning) yet is still comes on sometimes. Despite all this, the car seems to run just fine.

It makes you wonder if I am paying for unnecessary work, perhaps it needs a new ECU?

I also had new windscreen wipers 2-3 weeks ago, so it is weird that they have gone again, they occasionally move very slowly but make quite a noise. That seems unconnected.
 
The sensor problem is so similar that I think it must be a known common issue. ECU is possible but is not definite unless someone confirms that it fixed the problem for him by replacing ecu. It also could be related to the instrument panel as the temperature gauge is also controlled by the sensor. I have not read the actual error codes that the ecu is registering which could provide some more clues.
 
Had car back yesterday, typically warning lights were not on when I took car in, so there were no error codes to read.

Anyway, he has replaced thermometer which was indeed sticking, he has replaced earth lead, and also replaced windscreen wipers free of charge as they were more or less new. Sorted out banging exhaust too.

So far so good, Only time will tell if I still get same engine warning lights.
 
Hope is sorted for you.
In my case the light has not come on this week but the temperature showed higher reading.
Check the coolant today and managed to add about 1.5L. So the head gasket is definitely on its way. I am wondering if the light coming on is about the ecu detecting unusual coolant variation due to head gasket failing and then throws an error? So I have much more serious issue then just the light.
 
Although this might sound daft...
Another earth lead to check which has been known to cause 'interesting ' problems on the Dashboard warning lights and sometimes wipers is the Earth lead on the rear light clusters. Sometimes also causes Brake light to Flash alternately with indicator when Indicator is on and brake pedal pressed.
Simple enough to sort out, remove the light unit and unplug the Connector. check the black wire in the connector and if needed clean the contact before reassembly.
 
Last edited:
I know its still early days and I've had no long distance journeys to do, but no more warning lights are coming on.


I think replacing that earth lead from battery, as Portland Bill suggested in post number 2, has sorted it out.


The car has always seemed to run well, its just alarming when lights come on for no reason.
 
Yesterday did it again for me. 5 miles before home temperature went to zero and never recovered until home (same conditions less the 8 degrees and long journey more then 1 hour). Home switched off engine and then ignition on again but no engine start and the temperature started showing ok again. I tried this again before and seems to be consistent.

Time to check that earth lead, just puzzled if the lead is faulty there should be a lot more issues with the electrics.
 
Back
Top