Technical water temperature max. for 5 seconds + beeps

[yellowstilo]

Did some searching on the forum but couldn't find an answer to this problem:

i changed the instrument cluster in my 1.6 Stilo (2002) by a colour display instrument cluster from a 2001/2002 Abarth.
Used my Examiner to do the cluster replacement procedure and did a Proxy alignment procedure to align it's programming to my body computer.
Everything works fine up to one "little" problem:
When I turn the ignition or start the car the pointer of the water temperature gauge goes to max. for 4-5 seconds, the warning beeps sound, the red warning lamp lights up (but I guess it always lights up during the check period?)
After this the pointer returns to it's normal position, beeping stops and red warning lamp extinguishes - everything works as expected after these 5 seconds....
No fault codes are stored in any node concerned- I also tried if any software updates existed on the Flash cd but no result.
Does anyone know how this little annoyance can be cured?
During my search on the forum i encountered several issues mentioning the same kind of problem but i didn't find a solution yet...
I hope somebody knows how to fix this....
thank you,
yellowstilo

 

[Greggers]

My Abarth has three wires coming off of the coolant temperature sensor and I believe your 1.6 might only have two. I think one of the wires is for the cluster and the other is for the computer...

It could be that the cluster is expecting information from the third wire but not getting it (because there is no third wire to feed the cluster), then failing to the information coming from the second wire (from the computer) hence the spurious reading for the first five seconds?

Sound feasible?

 

[yellowstilo]

Hello Greggers,
yes , that sounds feasable but I checked this on the Elearn cd (for the Abarth version) and at the third pin of the sensor it says NC (not connected) and only two wires are shown coming from the temperature sensor - one ground and one for reference signal.
I compared that to the schematics of my 1.6 L and it also uses these two wires.
The information about the temperature is sent on C-CAN by the engine-ecu and transformed into a B-CAN signal by the gateway inside the bodycomputer which is then used by the instrument cluster to determine what temperature is shown and if the warning led has to be lit.
Could you please check if there really are three wires connected on your temperature sensor?
I know I'm not the first one who has put an Abarth (colour) cluster in a non-Abarth Stilo and others didn't mention this problem.....
So I hope there is another logical explanation and solution?
Does someone have the resistance vs. temperature table for the temperature sensor in the Abarth so i can compare it to the values of the 1.6 model?
thanks in advance for your help,
yellowstilo

 

[john55]

If the reading is OK after the initial 5 seconds, then you have the correct temperature sensor for the car. Anyway, as the temperature is sent over the can bus, changing the sensor will not help, and will probably make your car run like crap because it needs to be matched to the engine ECU. I assume the can bus data is sent in K or degC, and not a value related to the resistance of the sensor.
I don't know about abarth's specifically, but a lot of cars have 2 temperature sensors, one for the engine ECU to use and one for the temperature on the dash display.
This is more likely a can bus data issue. Maybe the 1.6 ecu takes longer to initialise and start sending data so the display thinks there is a fault initially, until it receives the first temperature reading.
Watching the can bus data as the car initialises everything may give you a clue and if possible compare it to an Abarth when it starts. You say the data is routed by the body ECU, so there could be an issue here. Can you power up the display with the can bus disconnected, just to see if it gives the same behaviour. I think it probably shows a fault initially, by default until it is told not to by receiving the correct data.

 

[yellowstilo]

Hello John,
only one temperature sensor is used (that's one of the economical benefits of the CAN-bus technology...)
the temperature-data are sent on the CAN-bus as a degrees Celsius value (-40 to 215 degrees)
Your explanation of data being available too late might be plausible - however i never had this problem with my non-Abarth cluster.
Because the Abarth cluster is produced in 2001 it might be there is a fault in the software of the cluster - i know the early Stilo's suffered from many electronic failures which were solved by software updates.
Does anyone know of such issues regarding the colour Abarth cluster?
I will have a look on the can-bus data on high- and low speed can networks and see if i can find a delay in data delivery.
Thanks for your help, i hope i will find a solution because this beeping on start-up is getting on my nerves....

 

[yellowstilo]

i checked the B can-bus data for engine water temperature but the correct values are sent immediately on the bus so they are available for the Abarth instrument cluster.
I also measured the resistance value of the temperature sensor and it was correct too.
Then i simulated several values by connecting a 10k ohm potentiometer instead of the sensor and they all made the pointer to indicate the right value and producing the right value on the can bus (including a sensor fault warning when the resistance was too low..).
After i reconnected the sensor lead the pointer showed the right position on start-up once but all following start-ups produced the same fault.
I tried to reproduce this condition by disconnecting the cable, switching the ignition on (which produced the sensor-fault message because of the infinite resistance) , switching off , then reconnecting the cable but got the initial fault message (coolant temp. too high) for 4-5 seconds.
So my guess is it is a fault in the Abarth cluster software but I would be happy to hear some other suggestions from the Fiat-techs.....
Thanks,
yellowstilo

 

[john55]

This is not related, but I hope you can answer this question for me.
I presume the abarth had a Connect Nav+ fitted. Do you get the my car menu options on the display, or is it coming up like the connect nav ones, where the only thing you can set is the speed limit warning, and everything else has to be done throught the CN+. I want to know if I replace my dials, can I get the menu functions to come up or will it still be the same?
Thansk.

 

[Greggers]

I went through the testing of the temperature sensor with Deckchair5 and it definitely has 3 wires and not the two as eLearn states. Decks was as suprised as I was and I believe that one is the earth, one is for the cluster and one is for the computer...

If I remember rightly... one of the wires presented information when at the first stage of the ignition (MAR?) and the other kicked in when the engine is running... I don't know why, but that's what I found when doing the testing with a variable resitor replacing the sensor and watching the temperature guage...

 

[yellowstilo]

This is not related, but I hope you can answer this question for me.
I presume the abarth had a Connect Nav+ fitted. Do you get the my car menu options on the display, or is it coming up like the connect nav ones, where the only thing you can set is the speed limit warning, and everything else has to be done throught the CN+. I want to know if I replace my dials, can I get the menu functions to come up or will it still be the same?
Thansk.

Hello John,

in my 1.6L nothing has changed regarding the my car menu after installing my Connect Nav - all options are choosen by the menu buttons just like before the Connect Nav was added.
However it is also possible to change most settings using the Connect Nav menu.
I guess the Abarth which my colour instrument cluster was taken from also had a Connect Nav (as this was standard on the early Abarth's) - after fitting this dashboard nothing changed regarding the my-car options.
As far as I know the configuration in the bodycomputer determines how the my car settings are done - with the small button panel or with the Connect Nav if this is standard equipment.
Until now i didn't find any information how this configuration can be changed -
i guess it will be very difficult to change the standard factory configuration !
If you want to change the "missing" settings because of a faulty or missing Connect Nav it is possible to send messages on the can-bus containing the my-car settings and the time settings.
You will need a can-bus interface and appropriate software for this.
I have the knowledge how-to if needed.

yellowstilo

 

[yellowstilo]

I went through the testing of the temperature sensor with Deckchair5 and it definitely has 3 wires and not the two as eLearn states. Decks was as suprised as I was and I believe that one is the earth, one is for the cluster and one is for the computer...

If I remember rightly... one of the wires presented information when at the first stage of the ignition (MAR?) and the other kicked in when the engine is running... I don't know why, but that's what I found when doing the testing with a variable resitor replacing the sensor and watching the temperature guage...

Hello Greggers,

it is correct that the Elearn cd shows three connections on the temperature sensor.
According to the schematics there is a second sensor inside the same housing from which one side is connected to it's housing (earth) and the other side is the third connector you mention.
As mentioned before it says NC (not connected) and there is no wire shown on this connection.
However i can't find any info on the Elearn cd regarding a connection of this extra sensor towards the instrument cluster - the temperature value is sent on C-and B-can network and used by the instrument cluster (which don't have a connection for a temperature sensor....
So i'm very confused - until now i had only a few start-ups with normal initial temperature readings - on all other occasions the pointer goes all the way to "hot" and returns to it's normal value after 4-5 seconds.
At the same time the messages "engine coolant too hot - stop engine" and "cruise control activated" (which isn't) are shown.
After these 4-5 seconds everything works as expected without further fault messages.
I did some further searching on other forums and found out i'm not the only one with this problem - it might be it is a software-problem of the cluster but i didn't find a definite answer or solution to my problem.
I hope someone with "Fiat-connections" knows more about this (known?) problem and can supply a solution for it.
thanks for your help ,
yellowstilo

 

[yellowstilo]

Well, i just fitted another Abarth colour instrument cluster in my 1.6L Stilo and it has exactly the same problem:
at almost any start-up the temperature gauge goes up to max. temp. and after 4-5 seconds it drops to it's normal value.
This produces an annoying "beep-beep" an a "coolant temperature too high - stop engine" message.
It also produces a "cruise control activated " message although my CC is switched off.
After those messages everything is normal and all functions are o.k.
Occasionally a start-up is normal with real temperature indication and no beeps followed by "check o.k".
I'm out of ideas, maybe i will change my ignition swith as a test but i still hope some Fiat insider can tell me where this problem comes from....
(p.s. did the "replace cluster" and "proxy procedure" with my Examiner Smart...)
Hoping to get some helpful hints,
thank you,
yellowstilo

 

[Deckchair5]

Haven't got a clue really as you're always walking onto the dark side fitting parts designed for other vehicle set ups

It's obviously the pre start sensor checks that's causing the warning
but your engine temp is producing normal values at start up

Food for thought,
The Abarth instrument cluster will be expecting a reply from the Abarth oil temp sensor directly to pin 1 on the instrument cluster shown here from K29 - a normal looking temperature resistor. A set resistor to earth within values might make it happier?


Why would that make the coolant temp needle go to max with warnings?
Dont know, but it might be the only way the 1.6 body computer can communicate that something's wrong with one of the engine temperature sensor even though it's not the coolant temp sensor

Headache No.2
What kind of oil pressure gauge setup are you putting in as the 1.6 just has a simple warning pressure on/off switch whereas the Abarth has a proper oil pressure gauge fed from pressure variable resistor K28 going to into pin 2 on the Abarth instrument cluster

 

[yellowstilo]

Hello Deckchair,

thanks a lot for looking for a possible solution!
I also studied the schematics of the Abarth and found the sensors for oil temp. , -pressure and -level.
Because fitting a Abarth cluster has been done before by other forum members (Germany and Netherlands) and nobody mentioned this problem after having it proxy-realigned i did not bother about the extra sensor connections.
In the CAN-message from the body-computer I see a normal temperature value from the start but a flag for the warning lamp for 4-5 seconds.
Can somebody check if the coolant warning light lights up during the initial check under normal conditions?
the oil pressure setup doesn't give any problems after the Proxy procedure -the instument cluster is adapted to the 1.6 L behaviour so it doesn't show items regarding the Abarth setup like parking sensors, oil gauges etc.
Because the same happens with two different clusters i don't think of a faulty cluster, a software fault might be a possibility...
But i'm very happy with your idea's and will give it a try, i will do some experiments with dummy sensors connected to the right pins.
Does someone has a resistance value table for the different oil sensors?
Thanks for your help, any other ideas are still appreciated!
yellowstilo

 

[Deckchair5]

Yes it's normal for water temp red warning to light for 5 secs as a bulb test on start up checks
Could try a variable resistor and see what makes it happy. Good luck, as you're in uncharted territory

 

[yellowstilo]

Thanks for your quick reply - i will do some experiments regarding the missing sensors and post my findings...
Thanks again,
yellowstilo

 

[Andy Monty]

Have you checked the earth points on the battery /chassis and gear box there has been a similar problem on the Grande Punto section

two are the problems that cause the message of overheating.
the temp sensor has a pin with 5V from ECU and on the other
sends a level of voltage between aprox 1v (hot) and 4V ( cold).
when starting engine at cold, a latch of earth (minus) caused by weak contact from batery earth to chassis and/or gearbox , or a big current sucked by starter ( especialy hitachi ones) leads to a supply voltage to sensor of only 2-3 V Ecu receiving back a verry small signal of arround 0,6V meaning over 125 celsius, which causes the massege and stopping engine.
for gasoline engines there is a soft upgrade. for diesels look for uptold.

https://www.fiatforum.com/grande-punto-technical/141886-excess-radiat-what-2.html


Dont know if its of any use to you but its always the case you do the most complicated things first and when it all boils down its the simplest of things...

 

[yellowstilo]

Thank you Andy for this hint - I never look on the Punto chapter of this forum so i missed this one....
It all seems plausible reading this post - however i already replaced my battery by a larger one (60 Ah to 74 Ah) and never experienced this problem with my "low" model instrument cluster...
The part which wonders me is the drop of the 5 volt supply of the temp. sensor - the 12 volt battery voltage may drop while starting but the built-in voltage regulator should maintain it's 5 volt as long as the battery voltage doesn't drop under 7-8 volt??
the problem also occurs if i don't start the engine so i guess this is caused by something else...
But of course i will check the earth connection of the engine and gearbox - as you say most faults are caused by minor things like bad connections , low battery voltage etc.
thanks for your help, i will continue my research.....
yellowstilo

 

[Andy Monty]

no problems i had it on my GP anyhow to cut a long story short i cleaned the earth post, clamp, eyelet crimps and earth posts smeared them with a bit of copper grease and put back together and the problem went away :slayer:

its not the fact that the battery is low on charge its the dirty/ corroded/oxidesed (spl) contact that gives a high resistance path therefore reducing the voltage/current carrying capacity even though there is a voltage regulator if it cant get enough power to begin with the voltage will drop

(i think )

 

[yellowstilo]

thanks Andy,
i will clean the earth strap from battery and engine, will post results when done..

 

[yellowstilo]

Well, today I found a way around the annoing beeping when turning on the ignition or starting my 1.6L Stilo with the Abarth instrument cluster instead of the "low" version:
as i expected this to be a timing problem i built the delay circuit which is normally used for retrofitting a Connect Nav.
I changed the capacitor on pin 7+6 of the LM555 from 100uF to 47 uF to decrease the delay time.
I cut the dark blue wire of the cluster (switched 12v) and put the delay circuit in between these two wire ends.
I attached the earth of the delay circuit to the black wire of the cluster (earth)-
after some experiments i found that after 1-1,5 seconds delay the cluster doesn't beep anymore, the "checking" and "check o.k." are shown and the car runs fine.
As the body computer does 3 attempts within 4 seconds to check if all nodes are present this is not a problem.
Although the pointer of the temperature gauge still moves to "very hot" for a few seconds and the text "cruise control activated" is still shown at start-up i'm glad i can start the car without the 3 annoing beeps....
I realise this is not the final solution but it's not that urgent anymore to find out where this comes from....very rarely the car shows normal reading of the temperature but i can't find a relationship yet.
Of course i will continue to search for the cause of this annoing fault but if it can't be found this may be a solution for other Stilo owners with similar problems.
I will keep you informed about my progress...

yellowstilo