What does this relay control? FIXED

[easypops 8]

Hi All,

I asked in another thread about a constantly clicking(while driving) relay i have, its the upside down 53 in the picture.............i replaced it with another which just clicks like the old one, only louder :)..................So if someone could tell me what it is i'd be very grateful.........and if they could have a guess as to why its gone into click overload, that too would be most appreciated.

Looking at the other pic it suggests that it can only be(if the abs relays are behind the glovebox) the 'Coolant after-run control module'...........so if it is indeed part of the cooling system, which i guess makes some sense as i unplugged it and everything else seemed to still work..............so what would cause it to click like mad?..............i guess its constantly trying to turn something on?.........the fans?

Any help would be great

 

Thanks

Martin

Edited August 2, 2011 by easypops

[easypops 8]

Bumpty bump :)

[RW1 0]

It is the Lambda Probe Heating relay J278. The engine ECU drives it off ECU pin 28.

 

If you've swapped it, then the ECU control output on pin 28 is not happy.

 

The power to drive the relay comes off the Engine ECU relay (109) directly.

 

The lambda supply it switches in, comes off Fuse 18 20Amp.

 

I suggest you borrow a lambda probe and plug it in to the engine bay connection at the back driver's side corner without running the engine and see if it stops the relay chattering.

 

If not, then its a delve into why the Engine ECU output on its pin 28 is oscillating.

 

.

[dogger 10]

Radiator fan after run.

[easypops 8]

It is the Lambda Probe Heating relay J278. The engine ECU drives it off ECU pin 28.

 

If you've swapped it, then the ECU control output on pin 28 is not happy.

 

The power to drive the relay comes off the Engine ECU relay (109) directly.

 

The lambda supply it switches in, comes off Fuse 18 20Amp.

 

I suggest you borrow a lambda probe and plug it in to the engine bay connection at the back driver's side corner without running the engine and see if it stops the relay chattering.

 

If not, then its a delve into why the Engine ECU output on its pin 28 is oscillating.

 

.

 

Thanks for the info mate, although a lot of it is very much in the land of the unknown for me.................the relay is only chattering whilst i'm driving, it all quiet when i'm sitting at idle...........does this point towards the lambda even more?.............could the ECU relay be at fault as i know i have read that people seem to need to change this at some point?..............First thing tomorrow i'll have a look at the lambda wiring and see if there is anything visible...........oh and if it is a lambda issue, would/could that cause my hessitation/missing while giving it the lead boot?

Sorry for all the questions but seeing as i have your attention i thought i'd chance my arm as i know what you dont know about these things aint worth knowing :)

[RW1 0]

I think the only option you have at the moment is to check the wires are OK at the probe end under the car on the cat converter and/or change the probe itself. The rest is going to a fairly long digging around.

 

If the ECU relay 109 was at fault, the engine ECU would be troublesome as well.

 

.

 

---------- Post added at 12:19 AM ---------- Previous post was at 12:12 AM ----------

 

You've not removed the Carbon Canister by any chance?

 

.

[easypops 8]

Thanks for that, I'll have a look at the wiring/probe in the morning and hope its something easy enough to spot

 

---------- Post added at 12:32 AM ---------- Previous post was at 12:31 AM ----------

 

No the carbon canister is still there, its just started happening out of the blue?

[easypops 8]

Well it seems to be fixed, although i'm not 100% sure what actually fixed it :lol:

I bought a second hand lambda probe off quicky1980 to see if swapping that would help, while waiting for that to arrive i hardly used the car as it was just no fun to drive with the constant hesitation, but on one of the journeys i did use it, part of the throttle body broke , the locating hole for the throttle cable snapped off :bonk:, leaving me stuck at the cinema :lol:..........luckily i had a couple of cable ties so managed to bodge it to get home

Happened to mention it to Sam(quicky1980) and he mentioned he had a spare TB, which he sent out to me at super speed.Thanks mate :cheers:

1. Couldn't get the old lamba off as there is little to no access to get any leverage, plugs looked different too?

2. Did spot a wee bit of fraying on the lamba wiring at the end of the heat sheild, taped it up and slid heatshield over it

3. Swapped the throttle bodies over and found old one had one very loose bolt?

 

Put it back together and its now running like a dream, possibly the best its felt in the 2ish years ive had it?

Not sure if it was the lambda being unplugged and plugged bag in, the frayed sheathing being taped up , the replacement TB(my money is on this)

Fingers crossed it stays like this :thumbleft:

 

Oh and yes the relay has stopped chattering too :afro: