Technical No oil light but immobiliser light stays on

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Technical No oil light but immobiliser light stays on

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Feb 28, 2021
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Hi all,
I have a problem with a 16v 04 plate Punto Active Sport 1.2 - see previous thread/post "immobiliser problem".
Just wondering if anyone else has encountered this issue - oil light DOES NOT come on and the immobiliser light DOES NOT go off so car will not start. Everything else on the car is working - lights, blower, wipers etc. Am in the process of changing the oil switch next to the oil filter (once the part has arrived) just in case!
Many thanks in advance
 
Hi
Yes you did, but that thread did not have the additional info about the oil light. Just a long shot really to see if anyone else has come across this issue or if they are linked in any way. Still trying to get to the bottom of the problem, not easy as the car is at my sons house!
Hope I'm not wasting anyone's time!
 
Unfortunately none of the 'regulars' with the 188 tend to post much anymore


But.. as the biggest selling FIAT of the internet era

SEARCH should find a mass of useful info

I only had 2 1242's.. in Active trim.. and a Sporting

One was rotten.. so lots of niggles through poor earthing

The sporting had a Blown fuse that put the ABS light on..
And a dodgy alternator that sometimes was reluctant to charge :eek:


Where is the car actually based?

A 10 minute session with multiECUScan could do wonders :)

Charlie. Near the M4
 
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Hi Charlie
Thanks for this. The car is located in Lydney, approx 9 miles from Chepstow and the M48. Still hoping that a faulty oil sensor is the culprit, that or a wiring issue between the sensor and ecu. Awaiting arrival of new sensor.
Don't have access to a multiECUscan ��
 
Hi Charlie
Thanks for this. The car is located in Lydney, approx 9 miles from Chepstow and the M48. Still hoping that a faulty oil sensor is the culprit, that or a wiring issue between the sensor and ecu. Awaiting arrival of new sensor.
Don't have access to a multiECUscan ��


Hi

Message me later in the week

I can help organise some OBD testing if still required
 
Right.....
This is what’s happened to date.
ALL fuses and relays checked and al, in order. Multiecuscan software installed and registered. ELM327 cable used to connect car and laptop. Software recognises cable and says its ok (in settings) BUT when I connect it comes back with a message basically saying it can’t connect to ecu. Tried swapping ecu with a reset one (apparently) but get same results. Battery has needed recharging twice in a week (new 2 months ago) so have done a parasitic drain test and found a 0.01a to 0.05a drain. All fuses/relays checked again to find drain. When main 70a fuse was removed it read 0a. All fuses/relays in fascia fuse box checked with no change until main power plug was removed.
Thoughts appreciated.
Cheers
 
if you have a ME73H4F001 ECU you can take that out of the car and clone it to the same model ECU and you can do the same thing via the OBD2 port. I am supposing if you cannot read the ECU via the OBD2 port the wiring to the ECU from the OBD2 port is disconnected and it should be possible to trace that or bypass the fault with new wires.
 
Hi judderbar
Thanks for the reply. Yes the ecu is that type. Will the fuse box have to be removed to access the wiring at the rear of the OBD port - I’m assuming So! Can anyone point me in the right direction for a good, clear diagram of this circuit? The spaghetti that currently exists in and out of the ecu is confusing my little brain!! Don’t find the Haynes manual very helpful as I can see no reference to the ecu wiring.
Thanks again for responding, it is very much appreciated.
 
Hi judderbar
Thanks for the reply. Yes the ecu is that type. Will the fuse box have to be removed to access the wiring at the rear of the OBD port - I’m assuming So! Can anyone point me in the right direction for a good, clear diagram of this circuit? The spaghetti that currently exists in and out of the ecu is confusing my little brain!! Don’t find the Haynes manual very helpful as I can see no reference to the ecu wiring.
Thanks again for responding, it is very much appreciated.

Lets back up a bit. Have you fixed the oil light?

There are two connectors inside the fuse box next to the battery which I believe connect the engine wiring harness to the body computer wiring harness. All the OBD communication to the ECU and oil warning light signal must be going via those plugs.
 
OK guys.....
I'm leaning more towards wiring, mainly because the only lights that come when the ignition is turned to MAR are:
On the Speedo clock:-
Handbrake
Power steering - but goes out after a few seconds
ABS - also goes out after a few seconds

On the Rev counter face:
Battery
immobiliser
Flashing passenger airbag - goes out after a few seconds
Airbag

What other lights should I be seeing - bear in mind it's my son's car so I don't drive it.
 
Grand
Thanks Judderbar, any idea how can I check these?
The vehicle has been standing outdoors in all weathers so it's quite possible for water to have got in somewhere - scuttle drains as Varesecrazy suggests.
 
I did some digging around................first via google and then confirming my car fits the ME73H4 information available.

Here are some photos of the K-line diagnostic wire which multiecuscan is using to get the engine information. The wire is white with a red stripe. The K-line wire is at battery voltage or pulses at that voltage so you need to be careful with your test wires.


It is on pin 2 on the engine ECU plug nearest the radiator and then goes thru to pin 7 on the obd2 plug.

This wire must be on a relay in the body computer because when the engine fuse box plugs are unconnected there is no connection between the OBD2 plug at pin 7 on the body computer and the connector next to the battery. The k-line wire is going from the engine via the connector without otherwise going thru the engine fuse box components.
 

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More fiddling..................

https://canlogger1000.csselectronic...ink-16-Pin-Out-J1962-Explained-What-Is_v2.png

If I connect pins 16 4 and 7 from the OBD2 port to my OBD2 cable I can use multiecuscan to detect my engine ECU

If I then take the laptop to the engine with the obd2cable I can connect 16 to battery positive, 4 to battery negative and 7 to the white and red wire on the connector I highlighted before and detect my engine ECU.

But maybe this is getting too complicated? The fiat OBD2 socket uses 7 for the engine and other pins for the other ECU. If I disconnect the engine ECU plugs I can detect the airbag and ABS. ABS is on pin 1 airbag on pin 3?


It will help to know if the OP has got any information from multiecuscan.
 
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