filipharvey

Just removed plenum, no sign of split wires there. If I disconnect all 4 lambdas, the faults still say invalid signal - surely it should change to no signal? Only the precat lambda on bank 2 changed its status to that.

Ok, well the front cover is off - has been for some time. I'll take the plenum off tomorrow and check for any signs there. Unlikely that I'll be at SAD.

If the lambda alone is unplugged, no it doesn't clear. Plug B has to be removed from the ECU itself for the fault to clear. Yes, have tried another MAF. The ECU is earthed to the body as it was relocated to the bulkhead when I put the 3.0 in. The earth leads to the block and cam covers are good too. Not sure where to check the earths to the sensors themselves though? Thanks mate

I'm aware the engine won't start, but my thinking was that as the fault shows even with the engine off, and reappears as soon as plug B is reconnected to the ECU (it won't clear with it connected) then I don't need to go as far as starting the engine with a different ECU. However, if you think there is a chance of blowing another, I won't try it. I do think that the shorting lambda wires are the likely cause though, and that has been sorted. I have swapped all of the relays in front of the battery around, and the fault still shows. I know you really need to see it hands on, but you are a long way from me. Is there anything else I should be looking for diagnostic wise?

Well it is all back together and the fault is still there, so it must be a fuse, relay or the ECU. Does anybody know where that fuse/relay is???

Well the exhaust splitting may well have been a good thing! During all my fiddling around, I had only checked and cleaned connections, not the wires themselves. Whilst I was under the car removing the downpipe, I noticed that the front in-cat lambda wire was split - both white wires. Those are the two that power the lambda heater, and by the looks of it they had been touching where the bare wires met. I'm gonna take a wild guess, but I reckon this is the cause of all my problems. So, what I need to know is; a ) Where is the fuse for the lambda heaters? b ) Is that fuse shared with the MAF or EVAP control? I've checked most of the fuses above the main fuse box by the driver's knee, but they all seemed fine. I'm hoping that there is actually a fuse for them, otherwise this will definitely have goosed the ECU!

I'll have them off you if you can find them. I'll probably be able to get these patched up for now, but the flexis weren't brilliant when I bought them from AL, so a spare set will be handy.

Was expecting it to be the flexi, but no, the actual pipe has split all the way around the weld.

Yes, they are CF3 downpipes mate.

Well Casson has said I can use his. But to top all this off, I just went down the road and one of my down pipes has split. Bollocks!

That's even better being a 156, although it doesn't really make much difference if I'm putting your ECU on my car rather than the other way around. I'd be happy to meet you somewhere, but I'll see if Jim will do it first. I'll get back to you once I've checked the pinouts and I'll have a word with Dan to make sure all was ok when he tried it.

Thinking about it, I'm sure Dan said he has used an ME3.1 on a GTA to see if they could be used instead due to the GTA's failure rate and rarity, and it was fine other than a few fault codes. I'm almost certain the pinouts are the same, but I will double check. Whereabouts are you anyway mate? 156 or 147 GTA - can't remember what you've got!

Will do. I might have a word with Casson as he's probably closer than you - but he's fairly precious over his GTA so probably wouldn't allow it

If the pinouts are the same, it would be enough to test it. The ME3.1 of the 2.5/3.0 and ME7.3.1 of the 3.2 are near identical ECUs. I'll have to check.

Think I can get a set from AL for about £160, so it's not too bad. Just don't want to buy one to find out that wasn't the fault after all. I do wonder if either the 3.0 GTV or 166 codebox will work on the 156? The ECU will as they are all ME3.1's but I would need the codebox and immobilser chip to match. It would save me getting a remap on a 2.5 156 one.

To be honest I'd be happy if it was the ECU, at least that would be an easy fix with a new one and code box. I don't know anyone nearby with a CF3 V6, otherwise I could try their ECU on mine. It's a shitter cos all the work I put into doing the 3.0 conversion is rendered pretty pointless at the moment as it is so down on power - feels just like the 2.5 did.

Does anyone know which are the lambda fuses/relays on the CF3 V6?

Just let the car warm up for a bit, and the following codes were shown: P0100 Mass Air Flow (1) [signal Low] - Fatal P0340 Camshaft position sensor [signal High] - Fatal P0443 EVAP circuit (4) [signal Low] P0135 Preheating resistance 1 above cat [signal Low] - Fatal P0155 Preheating resistance 2 above cat [No Signal] - Fatal P1135 Preheating resistance 1 above cat [invalid Signal] - Fatal P1155 Preheating resistance 2 above cat [invalid Signal] - Fatal P0141 Preheating resistance 1 below cat [No Signal] - Fatal P0161 Preheating resistance 2 below cat [No Signal] - Fatal P1141 Preheating resistance 1 below cat [invalid Signal] - Fatal P1161 Lambda 2 signal below cat [invalid Signal] - Fatal I don't recall seeing the cam sensor show before, and it didn't appear until after it had been disconnected and reconnected. I cleared the codes, ran the engine again and it reappeared. Yet again the following codes refuse to clear, even when the engine is switched off: P0443 - EVAP Circuit (4) - [signal Low] - Fatal P0135 - Preheating resistance 1 above catalyst - [signal Low] - Fatal P0155 - Preheating resistance 2 above catalyst - [signal Low] - Fatal The MAF code (P0100 Mass Air Flow (1) [signal Low] - Fatal) used to only show once the engine had been revved, however it now shows as soon as the engine has been started. During the warm up, the lambda heaters were switching constantly on and off, which obviously isn't right either.

Indeed.

It's not that which is the problem, it is the ECU not receiving or showing a signal from a number of sensors and throwing random fault codes. Had the back of the ECU off last night and it all looks ok, but the wiring is so tiny it is hard to tell. Thanks for the help chaps, but a simple throttle reset isn't going to fix this.

I've finally managed to have a look and all connections at the plugs on the ECU seem fine. I did suspect the ECU's earth because I had relocated it to the bulkhead when I put the 3.0 in, but I made another earth and the same errors continue to show. Do the MAF and lambdas share an earth/connection elsewhere at all? When I disconnected and reconnected the ECU this time, on first start it would barely run and it ignored any throttle input. Restarted and it ran fine again. Almost identical to when it lost the signal from the coolant sensor. The list of faults was pretty long this time - I stupidly cleared them after I had made a new earth to see if they would clear without taking note of them. Again, the lambda and EVAP codes would not clear, yet everything else did. Once again the MAF code came back as soon as the engine was revved. The other codes (I will make a note next time) only seem to come back on a run - not when parked.

I'll have a closer inspection on the weekend and get back to you. Thanks for your help so far!

Well..... Car refused to start on Saturday and the cooling fans were running constantly on full pelt - no signal from the temp sensor. After I disconnected most of the connections in the engine bay and at the ECU, it just about managed to fire up. Touching the throttle killed the engine though. I managed to feather the throttle a few times up to around 5k revs - the more I did this, the easier it did it, but idle was lumpy as custard. I turned it off, restarted it and it ran fine. Reset the codes again and the only two remaining were the original lambda codes. All other codes mentioned in the posts above returned after a drive however. There were additional codes of 'low signal' along with the 'no signal' that was there before, so I may be getting somewhere. I'm now on occasions getting 0.047v from the MAF at idle I'm still wondering if it is the ECU though, and that when I reconnected the 2 plugs it moved the pins enough to make contact with the PCB, albeit a poor one. I'm assuming there that the issue with the ECU would be dry solder.

Only the one key.

Checked those too and they all seem to be in good condition. The only plug I've found to be corroded is the multiplug on the near side chassis leg.