Hi guys,
ive read the above codes and need some help, the car starts for about 10 minutes ten it cuts off and will not start again till it cools down.
The codes refer to the injectors (1,2,3,4) and the ignition coils A&B, however the cause symptoms are shown as Wiring, coils, and ECM on all codes.
I have been told that i will have to replace the ECU, please advise, i would be very grateful.
I have managed to clear all the codes but the car still has the same problem mentioned above and management light keeps flashing, however the codes have not re-appered since i got rid of them even while driving the car.

The ECU Serial is: IAW4AF.M91
Its a 2003 seicento and has only done 13,000 miles.

Before condemning the ECU, check that you have a permanent 12v supply to the coils and injectors with ignition on.

Coils and injectors are negative switched by the ECU so a 12v +ve supply is common to all of them.

ECUs very seldom fail, often unpluging and reconnecting it (with ignition off) will cure a problem.

Dave.

Davren said:

Before condemning the ECU, check that you have a permanent 12v supply to the coils and injectors with ignition on.

Coils and injectors are negative switched by the ECU so a 12v +ve supply is common to all of them.

ECUs very seldom fail, often unpluging and reconnecting it (with ignition off) will cure a problem.

Dave.

Click to expand...

my mechanic tried unplugging as you say but it didnt work, he thinks it requires an ECU as its getting warm. thanks i will try the voltage supply.
any other ideas you may have will be appreciated.thx

Hi

I'd also try the bonding (earthing) straps.

Check for physical damage of wiring or corrosion.

I.e. remove the fastner that holds down the lug and clean all surfaces to silver then coat with copperslip grease and remake.

If it is still doing ten minutes the ECU is hanging on..., some thing else wrong...

Noel
Think there are three bonding straps do all three...

The late type ECU (as you have) is very reliable. I'd be inclined to visually inspect the wiring, do the old start it up at night, bonnet open, and check for flashes routine (blue flashes indicate a HT leak, orange flashes a LT leak), use a single jump lead from battery -ive to somewhere near the coilpack to eliminate earth faults (very common on the Cento).

Getting the codes is one thing -- interpreting them and fixing the fault is quite another. Many garages, even FIAT ones, have the first skill but not the second. IIRC, there's yet another code for an ECU fault.

Pep0 said:

Hi

I'd also try the bonding (earthing) straps.

Check for physical damage of wiring or corrosion.

I.e. remove the fastner that holds down the lug and clean all surfaces to silver then coat with copperslip grease and remake.

If it is still doing ten minutes the ECU is hanging on..., some thing else wrong...

Noel
Think there are three bonding straps do all three...

Click to expand...

I have checked all the wiring, cleaned all the earthing wires and still no luck. still cutting. plugged in code reader and no codes. any suggestions

fingers99 said:

The late type ECU (as you have) is very reliable. I'd be inclined to visually inspect the wiring, do the old start it up at night, bonnet open, and check for flashes routine (blue flashes indicate a HT leak, orange flashes a LT leak), use a single jump lead from battery -ive to somewhere near the coilpack to eliminate earth faults (very common on the Cento).

Getting the codes is one thing -- interpreting them and fixing the fault is quite another. Many garages, even FIAT ones, have the first skill but not the second. IIRC, there's yet another code for an ECU fault.

Click to expand...

i have checked all the above, cleaned all the earth and tried with the jump lead as you suggested, still cutting off.

If it's shoing no codes, there's either an issue with the code reader or...........?

My on experience goes something like this: my Sei decided to develop a fault in the middle of Southport -- a horrible misfire with the code light on. I popped it into the local FIAT who found no less than 8 stored codes, but wanted a couple of hundred quid for "further examination".

I replaced the leads and coil packs, discovered that the aftermarket induction system was effectively grounding out the HT leads, made sure that stood off and it has been fine ever since (touch wood). Diagnostic systems 0, start it up at night with the bonnet up 1.

That it's cutting out without a fault code suggests, to me, TDC sensor. Check -- when it cuts -- for spark and fuel past the injector (pull one injector, if need be).

Simpler to order a TDC sensor and change it for caution. Saves stopping in middle of round about...

Noel

Pep0 said:

Simpler to order a TDC sensor and change it for caution. Saves stopping in middle of round about...

Noel

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i think we found the problem the water temp sensor can someone tel how to remove it, does it need a special tool. when unplugged the car idles fine, it stays for longer. iv just got the new switch

This is MPi so a bit of a mystery to me, but I would have though it simple unscrews once the cable plug is unclipped.

Cheers

SPD

rallycinq said:

This is MPi so a bit of a mystery to me, but I would have though it simple unscrews once the cable plug is unclipped.

Cheers

SPD

Click to expand...

its not that simple its moulded to the plastic housing. theres hardly any room to put a spanner in

The sensor (the green one) itself will unscrew, but is sold complete with the plastic bit it screws into, which -- IIRC -- clips/bolts to the inlet manifold itself. Remove the inlet mani and all will become clear.

fingers99 said:

The sensor (the green one) itself will unscrew, but is sold complete with the plastic bit it screws into, which -- IIRC -- clips/bolts to the inlet manifold itself. Remove the inlet mani and all will become clear.

Click to expand...

ok thx give a try