Technical U1600&u1601 [ECU poor contacts?]

[Geyta1983]

Hi there,

Every week my stilo cuts out a few times, i bought a code reader from ebay and there are two error codes storred:
u1600 Key not recognised
u1601 C-can network fault.

Didn't go to the fiat dealer yet, but can this be due to a battery problem?

I did the free stuff first mentioned on the guides section. The car runs better, but stil having the problem.


Cheers

 

[Deckchair5]

re: U1600&u1601 [ECU poor contacts?]


As you have U1600 key not recognised and can bus fault, i'd have a look here at the immobiliser chip recognition pick up aerial ring at the ignition switch. Seems to be a common problem with poor electrical contact here.

Look for poor wire contact at the connector

 

[danhans115]

re: U1600&u1601 [ECU poor contacts?]

Might also be worth checking the connections to the body computer. The immobiliser pick up ring and both B-CAN and C-CAN connect to it. The BC is the part that forms the diagnostic connector where you connected your code reader.

 

[Geyta1983]

re: U1600&u1601 [ECU poor contacts?]

Thanks for the quick reply's. I ordered the key barrel(antenna) just in case, wil take a look at the connections and clean them. Hopefully it's that simple!!! Will let you know the outcome!

 

[Geyta1983]

re: U1600&u1601 [ECU poor contacts?]

Changed the antenna ring and cleaned the contacts with contactcleaner, but still cutting out. Any ideas?

 

[Deckchair5]

re: U1600&u1601 [ECU poor contacts?]

Presuming it's still firing up the same fault codes then I'd look for open circuit/poor contacts from the Body computer M1 through the D4 connector to the ECU M10 as that's all can line



You haven't said what engine it is as connector numbers are different- refer to your engine size on the diag

 

[Geyta1983]

re: U1600&u1601 [ECU poor contacts?]

Today it didn't throw up any faults, just a loose connection on the display of the car. I don't know why it sometimes give a u1600 and/ or u1601 fault en sometimes not. After the cutting out i can not connect my obd reader to read the fault codes. I have to wait until the loose connection disappears. Thanks for the wiring diagram!!! Today when i put the stilo in revers the rear wiper start to clean the window, seems like i suddenly have an earthing problem to!! :-s maybe a part of the problem?

 

[Deckchair5]

re: U1600&u1601 [ECU poor contacts?]

You haven't told us what engine you have

Loose connection could be something entirely different-like battery earth- especially as your fault reader won't connect either, that needs 12v on pin 16

If you're not getting U1600 and U1601 then you may have cured the immobiliser recognition problem

rear wiper coming on automatically when you have front wipers on and select reverse is normal

 

[Geyta1983]

re: U1600&u1601 [ECU poor contacts?]

I have a 1.6 16v stilo. The car still cutting out and can not immediately start it over again, so it seems like the symptoms are the same. The code reader get's electrical current because it start up OK but not making any connection to the stilo. Yesterday i checked al the fuse, nothing strange over there.

 

[Deckchair5]

re: U1600&u1601 [ECU poor contacts?]

Describe what happens and under what situations when your engine "cuts out". Does it just die with nor warnings? Only on tickover? Does it tickover fine then just stop? Only when engine is hot?

If your engine just stops/ just won't start with no sign of life then miraculously just restarts as if nothing happened and states "Loose connection" then I'd check out your rpm sensor

There needs to be low resistance ie continuity of circuit through the sensor, good contacts at the connector, air gap between sensor and pick up ring correct

 

[Geyta1983]

re: U1600&u1601 [ECU poor contacts?]

It seems that the engine cuts out random. I was trying to see a pattern, but i don't think there it any. It can do it after 5 miles, 10 miles, 20 miles or the second i start it up only happens twice. But more whilst i am driving, maybe coincidence. It can occur whilst in tickover, running on highway with steady rpm, in heavy traffic basically everywhere. It just completely cuts out, with some warning light's, like ebd, and esp and loose connection. But when i read the fault code there is no sign of any ebd trouble or esp. So i think the car just throw's up anything on the display. After the problem occured i can start it fine with no problem, i did have a few times that the car was running very rough but usualy it start perfect. When i don't leave the car alone for 5 - 10 minuts and force it to start sometimes it starts up, but cuts out after 4 seconds, maybe less then 4 seconds.

Sometimes the car is a little bit struggling before it cuts out, i can almost feel it comming up. Because i first thought it was engine like i bought new spark plugs and a coil to change one coil that didn't look to nice. The car is running much better, but still having the problem.

I saw that the RPM sensor has been changes 6 months ago by the previous owner i can read in the maintenance log.

 

[Deckchair5]

re: U1600&u1601 [ECU poor contacts?]

Sounds more like an earth fault particularly ECU to earth. That would explain your u1600 immobiliser fault and why you can't get your code reader to read off the ECU when fault is there and the "Loose connection" warning

Won't be the first time a crank sensor has been fitted badly too

 

[Geyta1983]

re: U1600&u1601 [ECU poor contacts?]

I think i am gone make an extra earth to ecu, do you mean the body computer or engine management ecu?

Also will check the rpm sensor!

 

[Deckchair5]

re: U1600&u1601 [ECU poor contacts?]

Engine ecu
You're looking for an open circuit/poor connection. It could be at the ECU connector itself
Happy hunting!

 

[brocherboy]

re: U1600&u1601 [ECU poor contacts?]

Sounds more like an earth fault particularly ECU to earth. That would explain your u1600 immobiliser fault and why you can't get your code reader to read off the ECU when fault is there and the "Loose connection" warning

Won't be the first time a crank sensor has been fitted badly too

Just to throw my penny in the ring,i had the same problem on my abarth with the constant "loose connection" to the point car would not start at all ,ordered and changed the crankshaft sensor and away she went £31 well spent

 

[Geyta1983]

re: U1600&u1601 [ECU poor contacts?]

I did some checks, and disconnect the ecu. Getting exactly the same message like asr and loose connection, when i try to start the car security failure comes on seems like the problem is somewhere in the connection of the ecu. It definitely looks like it's coming from the ECU.

 

[Deckchair5]

re: U1600&u1601 [ECU poor contacts?]

Good stuff! You're on your way then

 

[Geyta1983]

re: U1600&u1601 [ECU poor contacts?]

So this is what i found out, it was cutting out again. Try to see what's wrong in the engine bay. Pressed on one of the two connectors of the ECU and hear the system starting up. So this rings bells. I cleaned the connector with contact cleaner and as i was cleaning i felt the temperature of the ECU, it's the one on top of the engine and it's bloody hot. So knowing that bloody hot and cold conditions can do tricks with wiring. So i tried to isolate the ECU rising it up 1/2 inch so the back of the ECU is not resting on a metal plate but in the air, and isolating the bolts with rubber rings. The ECU definitely feels much colder than before and driving now for three days no problems occured since then and that wasn't before. So hope it stays.

Thanks anyone for the tips!!

 

[Argonought]

Sounds a great fix to me

 

[Deckchair5]

Your ECU shouldn't ever be getting hot to the touch

Hot temp equals short circuit- short circuit low enough in resistance to produce high current. By moving the ECU you have probably moved the connector wiring enough to temporarily stop the short circuit

That would worry me a little so I think I'd look for crushed wiring or blackened insulation close to the ECU connectors.

Just a heads up, not to alarm you but unfused short circuits lead to fires. You're right on the location of the fault now, you just need to fix it permanently