Engine Management Light Code 443 - EVAP circuit at fault.

[nabbers]

Swapped the engine for a s/h unit and also dropped the petrol tank to fit new gear cables.   During this process I did knock the charcoal canister on the O?S rear inner wing, but I don't think that's relevant....

I've been trying to get my head around this issue for a while now.   

Basically after cancelling it again,  the EML comes on after about 10 minutes and code reader tells me the problem is P0443.   This seems to be described as a EVAP Circuit failure

So my first thought was it could be electrical, but maybe "circuit' refers to the pipes? 

So far I've checked the evaporations solenoid by putting power through it and blowing; Power off its blocked, power on its open so that's working as it should.   

I've checked each pipe carefully for holes or splits and made sure they are pushed onto spigots and the clips are in the right place.

Maybe I disturbed a pipe or wire when I dropped the gas tank?   But not sure what there is as the various online manuals seem to refer to USA models.

Knowing how the system works would be a help and also what venting applies to the UK gas tank?   Maybe I disturbed the rubber gasket on the fill tube.    But I think there are other codes that would apply if it wasn't getting up to pressure?

Help appreciated!

[Call the midlife!]

There are 3 different valves/solenoids on the fuel/evap system including a vapour pressure sensor that sits in the cover plate over the petrol tank opening in the driver's side bin.
It's possible you've broken/disconnected that somehow?


Sent from my iPhone using Tapatalk

[nabbers]

There are 3 different valves/solenoids on the fuel/evap system including a vapour pressure sensor that sits in the cover plate over the petrol tank opening in the driver's side bin.
It's possible you've broken/disconnected that somehow?


Sent from my iPhone using Tapatalk

Thank you for your early response!

Highly likely!   I did stretch a wire to the fuel pump and historically this was also cause of a breakdown previous to the engine swap!!    Can you guide me to the sensor?  My bins are out, the metal hatch is lifted and I can see the wires all pushed into a connector and a couple of pipes..  Does one of those wires link to the sensor?

[Call the midlife!]

There should be two sets of cables passing through a grommet that sits in the top of the cover plate.
One connector should (I think) push down onto the fuel pump/gauge sender unit that sits in the tank.
Vapour pressure sensor sits on top of the sender unit, or around that area and the connector pushes on sideways if I remember rightly?


Sent from my iPhone using Tapatalk

[nabbers]

There should be two sets of cables passing through a grommet that sits in the top of the cover plate.
One connector should (I think) push down onto the fuel pump/gauge sender unit that sits in the tank.
Vapour pressure sensor sits on top of the sender unit, or around that area and the connector pushes on sideways if I remember rightly?


Sent from my iPhone using Tapatalk

Ah are you in the UK or is yours a US car?  You describe this US? set up.


All I have through/ under the metal lid is 6 wires on slim spade connectors into the sender/pump assembly and sealed with little blue 'o' rings.

[Call the midlife!]

I'm UK but it's possible I'm looking at something derived from that diagram, incidentally you can't put that on the forum as it's copyrighted so it'll disappear from the thread soon..[emoji23]  (MOD EDIT: Thanks J!)
It's not something I've done myself yet but I'll be fitting new handbrake cables at the weekend so I'll find out what I've got.
@shnazzle


Sent from my iPhone using Tapatalk

[nabbers]

Dug around and there are no sensors for this on UK cars, the ECU instructs the EVAP to open.   I did find out that the fuse had blown and continues to do so; Its fuse EF12.    Now reading faulty o2 sensors can affect this fuse, I fitted new sensors recently.   

[1979scotte]

Dug around and there are no sensors for this on UK cars, the ECU instructs the EVAP to open.   I did find out that the fuse had blown and continues to do so; Its fuse EF12.    Now reading faulty o2 sensors can affect this fuse, I fitted new sensors recently.   

Were the O2 sensors brand new genuine OE Denso units?
Did you replace all 3?

[jonbill]

Unless you put the plugs on the o2 sensors yourself, I think the problem is likely that you've somehow managed to ground the EVAP solenoid +ve supply. Perhaps it's pinched under the tank somewhere?

[nabbers]

Dug around and there are no sensors for this on UK cars, the ECU instructs the EVAP to open.   I did find out that the fuse had blown and continues to do so; Its fuse EF12.    Now reading faulty o2 sensors can affect this fuse, I fitted new sensors recently.   

Were the O2 sensors brand new genuine OE Denso units?
Did you replace all 3?

They aren't genuine, but came from a trustworthy source who vouched for the quality.  I replaced the ones in the Precat manifold

[nabbers]

Unless you put the plugs on the o2 sensors yourself, I think the problem is likely that you've somehow managed to ground the EVAP solenoid +ve supply. Perhaps it's pinched under the tank somewhere?

As far as I can tell, there is no wiring around the tank for this on UK cars.     New development, P0443 code has gone but replaced with P0155 and P0135,  fuse hasn't blown again.    I didn't put plugs on the sensors myself.        Someone on another thread has had the same chain of events fuse and codes the same but with a 2z swap.   

[1979scotte]

Dug around and there are no sensors for this on UK cars, the ECU instructs the EVAP to open.   I did find out that the fuse had blown and continues to do so; Its fuse EF12.    Now reading faulty o2 sensors can affect this fuse, I fitted new sensors recently.   

Were the O2 sensors brand new genuine OE Denso units?
Did you replace all 3?

They aren't genuine, but came from a trustworthy source who vouched for the quality.  I replaced the ones in the Precat manifold

Each to their own and I've never had a sensor fail but the establishment swears by genuine Denso sensors.

[jonbill]

Unless you put the plugs on the o2 sensors yourself, I think the problem is likely that you've somehow managed to ground the EVAP solenoid +ve supply. Perhaps it's pinched under the tank somewhere?

As far as I can tell, there is no wiring around the tank for this on UK cars.     New development, P0443 code has gone but replaced with P0155 and P0135,  fuse hasn't blown again.    I didn't put plugs on the sensors myself.        Someone on another thread has had the same chain of events fuse and codes the same but with a 2z swap.

Those codes are o2 sensor heaters open circuit I think.
So perhaps the heaters were drawing too much current blowing the fuse and throwing the 443 code and now the heater elements have blown.

As Scott says, denso sensors might be the answer.

[nabbers]

Hmm yeah that sounds like a possibility!   I'll get some new Denzo's