Technical Can I use an engine wiring loom from a 500 on my 2007 1.2 petrol panda?

[Uproaraudio]

I've got a 2007 1.2 petrol panda. It's developed a rough idle and hesitant acceleration. I've got fault codes p0204 (injector 4) and p0352 (Ignition coil B).

I've checked the 4th injector with a multimeter, and I'm getting nothing, so I'll be replacing that anyway. I've also swapped the ignition coils around but still getting the same fault code which leads me to believe it's a wiring issue.

Engine wiring looms for the 169s are sitting around £100 on eBay and are impossible to buy from the parts stores. 500s wiring looms can get as low as £30 and there seems to be more of them online.
The question is are they interchangeable since the engine is the same?

Any advice is appreciated. Or if you think I've missed something in my diagnostic please let me know!

Cheers

 

[koalar]

I've got a 2007 1.2 petrol panda. It's developed a rough idle and hesitant acceleration. I've got fault codes p0204 (injector 4) and p0352 (Ignition coil B).

I've checked the 4th injector with a multimeter, and I'm getting nothing, so I'll be replacing that anyway. I've also swapped the ignition coils around but still getting the same fault code which leads me to believe it's a wiring issue.

Engine wiring looms for the 169s are sitting around £100 on eBay and are impossible to buy from the parts stores. 500s wiring looms can get as low as £30 and there seems to be more of them online.
The question is are they interchangeable since the engine is the same?

Any advice is appreciated. Or if you think I've missed something in my diagnostic please let me know!

Cheers

Will it just plug in no ECU are are different

Most 500s 1.2 will have two identical size plugs

I suspect yours will have one large and one smaller plug

The wiring to the Cam sensor and Cam sensor even though they Look the same are different

 

[koalar]

Good probability the original problem will be in this joint

The power for the injectors and coils are all from this same point, it's failed in the past

 

[jrkitching]

The question is are they interchangeable

In a word, no.

since the engine is the same

It isn't. There are numerous differences, not least of which is that all 1.2 500's use the 69HP VVT engine.

 

[varesecrazy]

Indeed 2 generations

A 312 panda and 312 500 obviously closer in build

 

[Uproaraudio]

Good probability the original problem will be in this joint

View attachment 430986

The power for the injectors and coils are all from this same point, it's failed in the past

Thanks, Koalar. That's really helpful.

Do you have any advice on repairing the wiring if I find the culprit?

 

[koalar]

Thanks, Koalar. That's really helpful.

Do you have any advice on repairing the wiring if I find the culprit?

You need to confirm if this is the problem first

You can back probe the power pin on the injector, with a T pin or similar (brown and red I believe) it the wire that's the same colour on all injectors

Test light or multi meter on volts, probe on the t pin to earth, should be battery voltage with ignition on, wiggle the wires gently see if it goes out

The car not here at the moment, I can do a little video if you want

Reflowing the solder might be a problem, hobby soldering iron does not have enough energy as the mass of copper will soak the heat away, trivel job with a 500w iron

You might just be able to use one of these

Plenty of flux or fresh solder

 

[Uproaraudio]

You need to confirm if this is the problem first

You can back probe the power pin on the injector, with a T pin or similar (brown and red I believe) it the wire that's the same colour on all injectors

Test light or multi meter on volts, probe on the t pin to earth, should be battery voltage with ignition on, wiggle the wires gently see if it goes out

The car not here at the moment, I can do a little video if you want

Reflowing the solder might be a problem, hobby soldering iron does not have enough energy as the mass of copper will soak the heat away, trivel job with a 500w iron

You might just be able to use one of these

Plenty of flux or fresh solder

Awesome. Thank you!

 

[koalar]

A broken wire to the injector gives this error code, cylinder one was the easiest for me to get to, all further test are on injector 1

The code self clears after 5 starts without errors

On my car it battery voltage on the centre pin of the connector, ECU side

And this can be checked at the injector also

And 2.5V on all the other pins, ECU side

On the injector side of the connector still disconnected

Centre pin to any other pin is around 50 ohms

You can put a long reach handle screwdriver on each injector and your ear to the other, you can hear a distinctive tick as it fired, all 4 should sound the same

With this few tests we have checked

Continuity between the ECU and each injector

The resistance of the windings of each injector

Power is reaching each injector

And if the valve is opening and closing

It will not tell you the spray pattern

 

[Uproaraudio]

A broken wire to the injector gives this error code, cylinder one was the easiest for me to get to, all further test are on injector 1

View attachment 431027

The code self clears after 5 starts without errors

On my car it battery voltage on the centre pin of the connector, ECU side

View attachment 431028

And this can be checked at the injector also
View attachment 431031


And 2.5V on all the other pins, ECU side
View attachment 431029


On the injector side of the connector still disconnected

Centre pin to any other pin is around 50 ohms

View attachment 431030


You can put a long reach handle screwdriver on each injector and your ear to the other, you can hear a distinctive tick as it fired, all 4 should sound the same

With this few tests we have checked

Continuity between the ECU and each injector

The resistance of the windings of each injector

Power is reaching each injector

And if the valve is opening and closing

It will not tell you the spray pattern

This is incredibly helpful. Thank you. Getting my head round electrics is definitely an issue for me but this goes a long way to understand it better.