Standalone ECU A610

JohnC - I also tried a "working" A610 ECU in my car from J456 JTP which according to John Law didn't cut out. There was no earth strap fitted when I took it to bits.

In fact I tried 4 A610 ECU's and they all cut out...

Unfortunately Martin, that one way test is not conclusive enough. You need to have the two 610's together ... one with and one without the strap ... and swap ECU's to see if the fault moves from one car to the other or stays the same as the original installations.
It would be interesting to know if the 610's that do not have the cut out problem are the later Alp's built, as I am sure this fault showed up when the first 610's hit the streets and Renault was made aware of this problem ...... and whether later 610's had a modified or updated ECU fitted. Hence the question regarding the batch or board build numbers.

Hi John,

My car was originally J461 JTP so was one of the first. In my ownership (nearly 10 years) I have never had any experience whatsoever of the cutting out issue. I do remember when I bought the car that the previous owner mentioned that many suffered from this but my car never had. There is nothing in the comprehensive history file to suggest that the problem has ever been investigated either. My key is with an Alpine keyring and an aftermarket immobiliser fob - maybe this is the answer as fitment of this may have by-passed or modified the useage of the original anti theft switch to fuel pump relay - but no other keys. Do any other cars that don't suffer have an aftermarket immobiliser. Do any cars that do suffer have one?

In my experience of issues with ECU's (non Alpine), the main problems seem to stem from water ingress which obviously isn't an issue where they are positioned in an A610 (when compared to most other manufacturers, you actually have to commend Renault for not putting them in a harsh environment). MG/Rover for instance put theirs under the windscreen scuttle panel with a small drain hole underneath which gets blocked and the ECU's then sit in water and inevitably fail. The later Esprit's put the ECU underneath the rear window above the fuel tank in the engine compartment. Unfortunately, the window is prone to leaking causing water in the ECU and also on to the fuel tank which then rots. Fuel tank replacement due to rot is common on the Esprit's and is pretty difficult to do without taking the engine out. Either way, it is expensive and a complete bar steward of a job to do. There is two tanks as well. Still, any issues pale into insignificance when you look into parts prices from McLaren. Fancy a new battery for your MP4-12c, that'll be £3500 please sir. Failed steering rack, O dear, that's £33,000!! Ouch.

My gut feeling with the cut out issue is to look elsewhere. I don't think it has a lot to do with the ECU. Difficult to investigate when you don't have the issue but I can't help but feel it's more to do with wiring looms etc.

JohnC - I also tried a "working" A610 ECU in my car from J456 JTP which according to John Law didn't cut out. There was no earth strap fitted when I took it to bits.

In fact I tried 4 A610 ECU's and they all cut out...

Unfortunately Martin, that one way test is not conclusive enough. You need to have the two 610's together ... one with and one without the strap ... and swap ECU's to see if the fault moves from one car to the other or stays the same as the original installations.
It would be interesting to know if the 610's that do not have the cut out problem are the later Alp's built, as I am sure this fault showed up when the first 610's hit the streets and Renault was made aware of this problem ...... and whether later 610's had a modified or updated ECU fitted. Hence the question regarding the batch or board build numbers.

I seem to have inadvertently opened up the cutting out issue again! My car has not cut out since I have had it, but it has the earth strap fitted for the fuel pump relay.

For me, I think it's not worth trying to figure out the cause of the cutting out. There are so many advantages of going with a modern ECU, such as:

• Distributorless ignition - solve all the problems of damp in the distributor cap
• Fully mappable ignition, fuelling and boost - more power, better driveability (hopefully)
• Solve all the reliability issues with one stroke (providing you install a new loom)
• More understandable by modern garage equipment/laptops
• Solve the bridged fuel pump relay problem
• Ability to add features such as traction control, boost control per gear, etc.

These are just a few of the advantages I can think of off the top of my head!

I spoke to John at JL Engineering. He recommended that I used the Emerald K6 ECU from Dave Walker. He is able to have looms custom built for the A610 but the cost is quite high. £750 for the ECU and another £750 for the loom. He replaces the entire loom for running the engine and puts the new ECU in the factory location. It uses some of the factory relays, etc...

Having said that, my preference would be to build my own loom. I like the idea of the multi-plug for ease of disconnection between the engine and the car, so I would replicate that, but with a modern connector. I would also use a standard 36-1 trigger wheel and a Ford 6 cylinder coil pack.

If possible I would wire and install my own loom beside the original factory loom and then drive the car up to JL Engineering for final installation and mapping. Alternatively if I can get a base map, I'd consider using that to drive the car (gently) up to him.

I would also use an aftermarket boost solenoid valve and probably a wideband lambda sensor. With a wideband sensor, the ECU can self-optimise the fuelling map (apparently). I'd also look at installing an exhaust gas temperature sensor, which could help with optimising fuelling under boost.

Of course, Adaptronic is another option, as recommended by Chris at EFI parts. I suppose I just have to choose!

By the way, now that I mention the multi-way connector for the wiring to the engine, has anyone investigated this for a potential source of cutting out??

Andrew

[simontaylor]

Chris at EFI suggested to me that Exhaust Gas temp is not really needed or give much benefit until one is running BIG horse power, and i guess that means 500+ (I wish).

Early GTA has a 35 way multiplug in the engine bay, its a breeze when taking the engine out.
There is one other block connector for the starter/charge and battery connectors on the wheelarch.
Only other electrical connectors are 2 earth straps, speedo, reverse gear, and my external trigger sensor.

So then ..If mellow and big get together and big removes his strap on we have the perfect test bed.
It will mean running about in them on each others ECUs for a bit but they're good mates ....last I heard ..


Getting back to immobilisers.The 610 has a starter relay and it is that that is used on the OE setup.Not fuel pump .

Yes there are a lot of advantages to a new Ecu, however as there where so few of these cars ever made I think we have to be careful in how we modify them, otherwise it could have a detrimental effect on their resale value. That is why I said it would be nice if the club came to a conclusion on what system would be recognised.
Personally if I was in the market for a 610 I would be very cautious in buying one with fancy new bits put on it as it is a lot more complicated than a normal Gta Tubo.
The other problem I can see and John C might be able to answer this is cleaning out the engine bay there is a lot more wiring controlling petrol vapour and a load more solenoids diaphragm valves tucked underneath plus all the fan actuators are they all operated from the old Ecu, and if so if you change it for a new one do you have to keep the old one in to keep this stuff working.

All you are doing is swapping out the loom and ECU which can be reversed easily so I don't see it as an issue as long as you keep them safe .Apart from the dash/trip comp all the rest is easily sorted and reversable .Trip comp needs inj duty input and probably too much involved to make it viable....
All that is required is a trigger wheel and perhaps some new sensors which is a bolt on job anyway .

But ....I don't see the point in running aftermarket unless you are looking to modify the engine/fueling/turbo.OK,sure, to cure the cut-out but that has got to be something that just needs someone to investigate it properly and that's where the 'Club' could help but don't hold your breath .As for club approved ECU's ......feckin minefield

....... My gut feeling with the cut out issue is to look elsewhere. I don't think it has a lot to do with the ECU. Difficult to investigate when you don't have the issue but I can't help but feel it's more to do with wiring looms etc.

Hi John,

Good to hear from you on this subject and for the info of your early 610 with regard to there possibly being an upgraded ECU on later models. I had heard from the Big Man that your 610 did not need the earth strap for the fuel pump relay. I agree with you that it is difficult to investigate this problem when yours does not have it. Likewise I find it frustrating not having a 610 over here so I can only rely on the manuals and feed back from my comments.

For the benefit of those with an interest in the circuit we are on about, I have taken a copy of that part of the circuit I am interested in and coloured the positive feeds to the fuel pump relay RED, and the negative return feeds in Black. As I have stated before, this is a very simple circuit which operates the relay by putting an earth on one side of the relay coil once the engine starts to crank and TDC pulses are fed into the ECU. The positive for the relay coil is supplied from the Ign switch. I have marked the position where the Earth strap is connected to the relay coil earth as seen in Big M.s pic above.
I have studied both the CAU connectors and the ECU connector and I can find no link across from the CAU to the ECU. The CAU houses the immobilizer and as Lee (Clee) states, the CAU does have an output to the starter relay which interrupts the voltage to the starter solenoid. This does seem a very lightweight form of immobilization and there could be other forms of immobilization but I cannot find them from the circuits.
But as you can see the fuel pump circuit is simple and is operated solely by producing an earth at pin 6.
This is as far as I can go now with this problem, but if any other members can find the problem, please let me know ..... i really would like to hear from you.
Anyway here is the pic which will explain to any budding electrical / electronic members how little circuitry is involved.
I hope this is of interest ..... to some.

The other problem I can see and John C might be able to answer this is cleaning out the engine bay there is a lot more wiring controlling petrol vapour and a load more solenoids diaphragm valves tucked underneath plus all the fan actuators are they all operated from the old Ecu, and if so if you change it for a new one do you have to keep the old one in to keep this stuff working.

Stuart ...... I am really not the one to ask about this but on the face of it certainly some are operated by the ECU, but a different ECU may have the connections for these units especially if they are required for the efficient running of the engine.

Also a lot of good engineers like the DTA, I thought I would find out if the ecu issues are down to cooked wireing looms, once all my electrics are all sound and it still cuts out then it will point to ageing problems in the old ecu and to keep these cars reliabale and on the road new kit is required.
It will probably start happening in the Gta's at some point, those old resistors can't go on forever.

The GTA Renix 1 D501 ecu is pretty darn rugged,and doesn't have the level of fault finding later developed for the D502 and A610 series, plus it is not surface mount. A part from shorts killing output drivers in extreme cases, the D501 ecu will easily carry on for the life of the cars. I have not had problems with the electrolytics, and there is only a couple in the D501, rest are mostly ceramic caps. Resistors don't really age, provided they are not thermal stressed as they are all thick / thin film technology.

Martin

Martin F ...... I was hop[ng to meet up with you last year in Macon to discuss this, unfortunately you were not able to attend, so an opportunity missed sadly. But I would like to hear of your views on this fault.

Hi John,

Yes sorry, I had been looking forward to meeting you too. If nothing else than have a good chat about wiggly waves as someone put it to me the other day... I now have a NPD team, Electrical team, Compliance, and Wiggly Waves team...

I spoke to John at JL Engineering. He recommended that I used the Emerald K6 ECU from Dave Walker. He is able to have looms custom built for the A610 but the cost is quite high. £750 for the ECU and another £750 for the loom. He replaces the entire loom for running the engine and puts the new ECU in the factory location.

Seems pretty reasonable to me, by the time you have made up the loom, done the heatshrink, terminated the connectors etc etc... time to do it.. I get harnesses made up all the time to Mil grade, and GTA / A610 engine bays should be the same spec given the heat, and I budget on £500 a harness for qty x300 with MIL STD 38999 connectors, backshells, and double screened, DR25 sleeved, type 44 cabled harness...

Orbit12 (jamie) bought his 610 at the same time as mine and cured its cutting out by going over the engine loom and removing all high resistance connections. His theory (if I remember correctly) is the 610 ECU, being later than the GTA one, has some kind of cumulative fault counter and cuts the pump when it gets to that point. Turn off and on and you start the counter from zero

That came from me... I have the code, and had been playing around with these counters on a Fenix 3A ecu that has the same functionality.... found that back in 2012 /13 latest I think... the engine would randomly cut out at idle, restart on the ignition, and the engine would fire up fine...

.
I can help here, but pretty low on my priority list. I have a 610 ecu that is believed to cut, and I can run it on my hardware in the loop test bench with the relay, injector, and ignition loads, and simply leave it running... see if it cuts by itself.. I can defeat the counters in the code to eliminate them, and probably some other hacks, it just takes time... I have a factory proto Berex (Fenix 3b) ecu that will run an A610, and I can change the code unlike the factory fit ecu in the A610 series production. So I have the means to solve this, or more likely eliminate things, such as the ecu at some stage... but it will take a fair bit of effort, and not on my current todo list by a long shot.. hence, I have just read the thread from a point of curiosity mainly

Cheers,
Martin

Ok...here is another idea.
My concern about the strap is safety, if you have a crash, the fuel system will keep pressuring even if the engine stops.
For the fuel pump, the ecu is just acting as a watchdog, monitoring that it's firing and keeping the pump on. It doesn't care if the relay is there or not, the strap proves that.

My first fuel injected car, a 78 Saab, had a dedicated relay (Bosch k system) that did just that, monitored ignition pulses (points in those days) and pulled a relay to keep the pump running. It had a pressurisation cycle on power up, then waited until there was a pulse train from the ignition.
Rather than a full ecu replacement to delete the fault monitoring code (Martin thanks for confirming that idea) wouldn't a decent compromise be to add a similar device to monitor ignition pulses and turn on the fuel pump as required. That sounds like a swap of the fuel pump relay for a different type from a Bosch k car and a connection to the coil LV side to detect ignition or to the rev counter drive circuit?
You could also add the ford crash cut out as well for belt and braces and it should all fit in the standard location....
Of course you could also just repair or replace the engine loom, if there was a source. Anyone have a spare a610 engine loom to make up a template? The car Indistry today still uses peg boards to do this so once the loom has been measured, making a small run of looms wouldn't be so hard.