CEL on. Drives me crazy. Please, give some advices.

[chunki84]

2004 Cayenne 4.5 Turbo

 

 

With generic OBD reader: p2403

with durametric: p2451

P2451:
Evaporative Emission System Leak Detection Pump Sense Circuit - Value below lower limit value, test conditions are not-completed, fault is currently active and causing a DTC light

So far,

 

I replaced oil separator diaphragm

 

I replaced fuel cap

I replaced purge valve twice

I replaced leak detection pump.

I replaced canister + another leak detection pump.

 

I replaced whole canister assembly.

 

So, I replaced LDP 3 times so far.

No problem with filling gas.

 

Is there somewhere else I need to look?? 

Edited March 10, 2016 by chunki84

[Loren]

Exact model and year of your car please?

[chunki84]

Exact model and year of your car please?

 

2004 Cayenne 4.5 Turbo

[Loren]

P2403 Evaporative Emission System Leak Detection Pump Sense Circuit/Open

 

Possible cause of fault

- EVAP canister purge valve stuck in closed position

- Purge air line between EVAP canister purge valve and active charcoal filter blocked

- Open circuit in signal line

- Short circuit to ground in signal line

- Leakage diagnosis pump faulty (diaphragm or reed switch stuck, solenoid valve stays open)

- DME control module faulty

[chunki84]

 

P2403 Evaporative Emission System Leak Detection Pump Sense Circuit/Open

 

Possible cause of fault

- EVAP canister purge valve stuck in closed position

- Purge air line between EVAP canister purge valve and active charcoal filter blocked

- Open circuit in signal line

- Short circuit to ground in signal line

- Leakage diagnosis pump faulty (diaphragm or reed switch stuck, solenoid valve stays open)

- DME control module faulty

 

 

are there any other solution or suggestion than this?

 

I ve already tried to change bunch of stuffs on the list other than ECU.

[chunki84]

I changed ldp twice (even they are in good resistance values)

I checked valve on canister if it works at 12v.

Changes purge valve.

Checked purge valve (opens at 12v close at none)

Changed change over valve and checked with 12v.

Checked vacuum lines from both DVs to change over valve.

Changed cap.(I didn't think it's cap but I changes anyway)

Checked if there are any short/open circuits from ecu and valves on canister and ldp.

 

I found problem at mutiple vacuum lines

 

from DV to leak detection pump.

 

After I replace and rearrange. Issue solved. No cell or no code stored in ECU for 2 weeks now.

Edited October 26, 2016 by chunki84