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

[RDM1]

I know i never went short on anything with the car but the previous owner was a total jackass because i got the car with barely 1l of oil selespeed was empty (completely dry) plastics were broken everywhere, key seems like it came out of a world war and never gave us the second, the air filter were fixed with 5 additional useless bolts,... And the list goes on and on but I'm still trying to keep it going and fixing it one bit at a time but now falling completely dead I don't know anymore

 

[koalar]

Let's go back a step, we could be going round in circles

Since we have done a lot of testing the codes have change

P0335 not come back for some time

And I don't full trust the scan tool to be 100%

It would be nice to know if we still have no spark at first crank

It worth unlocking with the remote (some cars have a built in alarm and need unlocking with the remote before they will start)

Clearing any codes

And looking if there is a spark

 

[RDM1]

Will check it tomorrow but still pretty sure there is no spark because no RPM still which means ECU is still not responding to the CPS signal as for remote unlock i always and i mean always unlock the car with the remote unless the battery is removed and the hood is closed otherwise it's always and only via remote

 

[RDM1]

And the BCM stores the remote number upon unlocking as last remote used with the key number following so it's not related we need to find some power issue that I don't know where

 

[koalar]

Will check it tomorrow but still pretty sure there is no spark because no RPM still which means ECU is still not responding to the CPS signal as for remote unlock i always and i mean always unlock the car with the remote unless the battery is removed and the hood is closed otherwise it's always and only via remote

Not a good test

Once the code is sent at ignition on the BCM only sends current to the starter solenoid

Here's mine with low volts on the BCM there's no canbus information sent until the alternator is charging and the BCM reboots

So no RPM while cranking

or the first couple of seconds after it's fired up,

 

[RDM1]

Oook so what do i need to look for? Although mine used to always throw up the RPM upon cranking even when the battery was almost dead (the first one) it used to delay a little bit hardly ever until now

 

[RDM1]

Hmmm wait a second now i remember that even when RPM was delaying the car wouldn't start

 

[RDM1]

And also if the fault of low voltage is true shouldn't the BCM reboot while cranking causing the dashboard in whole to restart?

 

[koalar]

I only wanted to see if after the errors are cleared

And the CODE is sent to the ECU at ignition on

Accepted and sent back switching the immobiliser light off, with no errors

Whether the ECU actually recieving a crank signal at all before the immobilizer error kicks in as we are no longer getting the P0335

Something has changed

 

[RDM1]

What do you want me to do now then?

 

[RDM1]

And i think the ECU is not throwing the p0335 fault because the main issue is with the immobilizer because i already mentioned that upon clearing the BCM faults the car went out so we need to check about the BCM because honestly I have no clue about my vehicle's circuitry

 

[koalar]

Take a spark plug out

Short it to the engine block

Clear the codes

Crank the engine over once and physically see if there is a spark

I want to eliminate any network communication between the scan tool, BCM or dash

Does your scan tool connect to the ABS unit, is there a U170? Code present here as well

 

[RDM1]

No abs is completely clean with and without cranking

 

[RDM1]

Alright so cleared the faults and cranked, there is no spark and ECU returns a very delayed RPM (5 seconds after i start cranking)

 

[RDM1]

No dashboard feedback about RPM

 

[RDM1]

And with my current battery when the ECU started reading the RPM i got around 260

 

[koalar]

Great

So we 100% have a valid RPM signal 260 is good what I would expect from a worn out battery

The ECU isn't sending the information back to the scanner via the same network as the immobilizer and dash, so I don't know why there is a delay, It's almost like the ECU it's rebooting

I will have to look at the diagrams

A good first step would be to measure the power and ground to the ECU and see if it's dropping significantly, while I dive deeper

 

[RDM1]

You mean a voltage drop test?

 

[koalar]

For now let's just look at what the ECU sees

There should be a thicker white and red cable

Volts between here and the case while cranking

 

[RDM1]

Volts between here and the case while cranking
Didn't catch your point