Technical '06 Panda crank sensor issue.....

[RDM1]

Well done in sticking with it

I think the voltage drop is higher than expected when tested at the engine block

At the time of testing it was not enough to stop the car from running,

It's an intermitantant fault, there's no guarantees that it wasn't tested just as it was working,

It need looking at and fixing properperly at sometime

However all the amps from the starter motor are carried through the bolt on the gearbox and if this was the main fault I would expect the engine to cut out and the starter not to crank, unless there is another bodge somewhere with another earth has been added



There is a bolt with an earth cable just below the windscreen, what is the voltage measure between the stud and the battery negative, with the main beam on and rear windscreen on

Reply to this question in the bottom and there is 2 the 2nd is not quite visible btw in the video it's a bit deep

 

[koalar]

But now i am wondering what this U1700 DTC refers to because that's the first time it ever showed up now if you can please tell me if the BCM does have a ground wire somewhere to double check it

Its all part of the same power ground problem

 

[koalar]

Managed to throw an eye from the downside up viewing everything from behind the engine, everything is normally connected without any apparent issue i even wiggled the cables to make sure nothing is loose or maybe broken and it all seem fine I'm gonna go try with the multimeter checking continuity to make sure everything is fine with the connection on both starter and alternator

No no no

Power and grounds can not reliably be checked by using resitance, this will only find a completely broken cable, which we don't have

A strand the size of hair will still give 0 ohms when checked for reistance

But it will not carry 100 amps

Same with dirty connectors, when you put 100 amps through them they burn and make new connectors

You have to load the circuit and measure for a voltage drop,

I am off out now, back this evening

 

[RDM1]

No no no

Power and grounds can not reliably be checked by using resitance, this will only find a completely broken cable, which we don't have

A strand the size of hair will still give 0 ohms when checked for reistance

But it will not carry 100 amps

Same with dirty connectors, when you put 100 amps through them they burn and make new connectors

You have to load the circuit and measure for a voltage drop,

I am off out now, back this evening

Alright it's ok I'll be able to do that tomorrow so i could have someone to crank crank it while i do the voltage drop test

 

[RDM1]

Have a good afternoon

 

[RDM1]

But now come to think of it the U1700 means that there's a lost connection between the BCM and ECU and the grounds are all not related as i understood your shared explanation of the DTC

 

[A3jeroen]

Did you try a jumpercable between the battery (-) and engine?
You are performing al kinds of tests, come back with all kind of results, but nowhere do I read rsults from what is suggested above...

gr J

 

[RDM1]

I am going to do that but the question how is this going to bring back the communication between the BCM and ECU?

 

[MrMagoo]

A poor battery and suspect connections often present erroneous fault codes.

 

[RDM1]

The battery is good and i even tried jump-start it as extra but it didn't work

 

[MrMagoo]

I moved my earth connections from the chassis to the battery.

 

[RDM1]

Did you have the same problem?

 

[MrMagoo]

Nope.
But I know how finicky Italian cars can be with earths so it's precautionary measure.
I've had Alfa's and Lancia's that would not start due to poor earths.

 

[RDM1]

Alright noted gonna bring an extra wire to the engine and try jump start it simultaneously any other ideas?

 

[RDM1]

Hello everyone i know it's sunday and everyone is chilling out so if someone is feeling like seeing that's what I did with no faults on the ECU BCM and TCM

 

[RDM1]

And still won't start not to mention even with the extra battery based on the diagnostic tool the ecu is reading a drop to 10.3V upon cranking

 

[jackwhoo]

Hello everyone i know it's sunday and everyone is chilling out so if someone is feeling like seeing that's what I did with no faults on the ECU BCM and TCM

The extra wire from battery -ve to the engine is doing nothing to help the connection of the battery -ve to the vehicle body. The quality of the battery -ve to body connection cannot be overstated Most -ve connections are made to the body metal.

 

[RDM1]

And that's something i noticed during my active test not sure if you can hear the sound while the 1 and 2 one gets activated 3 and 4 both can't be activated

 

[RDM1]

And that's something i noticed during my active test not sure if you can hear the sound while the 1 and 2 one gets activated 3 and 4 both can't be activated

 

[RDM1]

One more thing is voltage drop test on the engine is 0.27v and immediate drop to 0.12 and ECU is 0.15 and drops