help: what does this do?

[paps78]

i was tinkering with my two cabs and i discovered that in my kreg i had a bit in the engine bay that my j reg did not. it sits behind the left hand side headlamp. I am curious to what the part does as they are both facelifts.


Secondly i also found this loose plug that is linked to the battery cables and on my j reg it is loose. on the k reg i followed the wire and it links onto the exhaust. Is it a sensor of some sort? and does the fact that its not linked on my j reg pose a problem and how do i fix it? the exhaust on the jreg was relaced prior to my ownership.


thirdly this cable is loose on my HT leads. i know where its meant to sit but what does it do? is it significant and how do i attach it on.

[TPS]

The First Picture is the ABS Control unit.

[paps78]

Thanks TPS. Guess I dont have ABS on my J reg then.

[paps78]

Thanks Willnz
i Looked on my exhaust and i didnt have any oxygen sensor on my exhaust there as is present on my other cab. The exhaust was replaced withan aftermarket one.
Do i need to replace the whole exhaust again or is there a way of fixing it??

[Grrrmachine]

Almost all cars will have the socket under the battery for an 02 (lambda) sensor, but not every car will have the sensor fitted. It's to protect your catalyser, so there's no huge worth in fitting the sensor if you don't have a catalyser. If you've passed an MOT recently, then you'll be fine; especially since the car is only a 4-pot engine.

Take will's advice on the HT leads though. For more info:

http://www.e30zone.net/e30zonewiki/index.php/CID

[Billwill]

I believe there is a single wire plug that sits under the black cover that runs along the bulkhead that has to be connected/disconnected depending on whether or not there is a cat fitted or does this only apply to certain models?

[paps78]

Thanks to everyone for the info.

[Duke137]

I have a set of those leads with the correct sensor in GWO for sale. PM me if interested

[Demlotcrew]

Get your economy back from that plug sensor

[e301988325i]

Second picture is the oxygen sensor connector. This needs to be connected to the oxygen sensor on the exhaust. It is likely to have been unplugged because the sensor is faulty. This will not do your emissions etc any good as the ECU will revert to a "limp" map. Better to check if it is working and replace if not.

The lambda socket should have a blanking plug if not in use, it connects electrically not just a weather shield, bound to be millions available s/hand by now.

Secondly, if you are not going to use the lambda you need to remove the lambda heater circuit relay if it is fitted. On the nearside turret there is a black cover approx 4" x 3" and underneath is the sockets for three relays. If there are two relays then the lambda relay is not fitted, if there are three then one is the lambda relay and needs to be pulled, it should be blue, but is interchangeable with the orange relay (fuel pump).

The three relays, should be white (DME) / orange (fuel pump) / blue (lambda heater).

The car will not run with either the DME or fuel pump relay removed so it's fairly obvious that if you pull a relay and the car won't run then it's the other one.

BTW: The circuit made by the relay tells the ECU that a lambda is fitted.

[Demlotcrew]

Second picture is the oxygen sensor connector. This needs to be connected to the oxygen sensor on the exhaust. It is likely to have been unplugged because the sensor is faulty. This will not do your emissions etc any good as the ECU will revert to a "limp" map. Better to check if it is working and replace if not.

The lambda socket should have a blanking plug if not in use, it connects electrically not just a weather shield, bound to be millions available s/hand by now.

Secondly, if you are not going to use the lambda you need to remove the lambda heater circuit relay if it is fitted. On the nearside turret there is a black cover approx 4" x 3" and underneath is the sockets for three relays. If there are two relays then the lambda relay is not fitted, if there are three then one is the lambda relay and needs to be pulled, it should be blue, but is interchangeable with the orange relay (fuel pump).

The three relays, should be white (DME) / orange (fuel pump) / blue (lambda heater).

The car will not run with either the DME or fuel pump relay removed so it's fairly obvious that if you pull a relay and the car won't run then it's the other one.

BTW: The circuit made by the relay tells the ECU that a lambda is fitted.

The above is true for an M20, not an M40. Relays are under the conduit running under the windscreen and for cat equipped cars there is a specific ECE KAT ecu.

[TPS]

It looks like an M40 Alex, If so the relays live under the bulkhead cover.

[e301988325i]

LOL. Yeah, looking a bit more closely, that M20's definitely missing two cylinders!!

As Andrew says, the M40 uses a cat specific ECU if equipped with a cat, so does not need the plug if it is non-cat.

When you say plug, what do you mean, the sensor itself or the cap?

Motronic with lambda control will default to using the AFM for fuelling with no lambda connected, based on the fact the cap is missing it's likely that it may have once had a lambda especially as it's a bit later on a J-plate.

[Jos]

Black Wire connected - CO setting on AFM controls mixture
Black Wire disconnected - uses O2 sensor to control mixture.

Black/Grey wire is pin 3 on the AFM if you need it, if you fit/have an O2 sensor that works you'll need to disconnect the wire as the offset from the AFM confuses the hell out of the ECU!