Hi all, We have a completely stock 2015 RS265 that we picked up for cheap as it had a broken cambelt (alternator belt fell apart and dropped into the crank pulley teeth) We sourced and installed a RS250 long block, changed the cambelt (using the proper cam locking tools), etc and installed it using the original harness & sensors. The problem is that it's injectors aren't pulsing, the engine runs perfectly off spray, there are zero stored codes and we're running out of ideas! We've switched out the cam and crank sensors, have manually fired the injectors using a jump harness and they all work just fine. The hot side of the injectors is just fine as well, the immobiliser seems to be inactive. Is there a specific ground circuit for the injectors that goes to the ecu? Anyone else had this issue?
I haven't had the problem but the following documents may help you troubleshoot The grounding map does show different earth points for engine (E) and injection(Y) - though I think "injection" for the French, refers to the EMS as a whole, not specifically the injectors. If you have access to DDT4All or Clip etc, you can work through engine start/run permissives, just to make sure its not a "logic" problem thats stopping the injectors from firing
Hi Zoto, I've downloaded ddt4all and the relevant definitions, but am having trouble getting the car to respond to any queries from the OBD2 adapters, I've tried my USB Cabled ELM327 and a Bluetooth one, but no joy - the software sees the adapter but no response from the ECU when it polls. Any tips?
Only the obvious one - you've got the car's ignition on? i.e. put the car into gear, then press start button for 5 seconds Depending on the quality of the ELM327 interface (ie chip type) many of the chinese cheapies don't work I've shown part of the ELM log file from a past connection so you can see whats typical - see if you can find it in your ddt4all folder , and post as it may shed some info. Also check if DDT4All software works in demo (Edition) mode.
Hmm, could be simple operator error then, I was attempting to connect it just by inserting the keycard working on the thought that with the dash powered it would be enough to access the system.
Easy to overlook - these French cars are "different" in many ways I would suggest putting a charger on the battery as it goes flat pretty quickly
Just grabbed one of our oldest Bluetooth adapters and it's connected now, now for the fun part - french/English translation!
So worked my way through all the permissives, etc - every appears ok, looks like I'll pivot back to testing the ecu side grounds.
If you get stuck, you could try forcing injectors on - will tell you if earth/ecu problem or interlocks/permissive Just need to be aware of risk using DDT4ALL in expert mode
All the earths tested up ok so we'll be trying this tomorrow, along with a few other things - like testing the injector drives with the injectors disconnected just in case one is pulling the others down (although I've tested all the injectors already and they all cycled)
To the best of our knowledge it is, we bought the car complete and unmodified in a not running state with a broken cambelt, dropped in a replacement motor and here we are now.
Do you know if the car was in an accident ???? I think there is something in thebecu that detects an impact, this is to shut off the fuel for safety, most cars have a resetaableswitch, but I know the meganes don't have that
The fuel pump and spark are still firing and all the permissives in the ecu are ok, as far as the ecu is concerned everything appears fine.
So we tested the injectors via ddt4all tonight, with some mixed results - when we told them to cycle, the injectors did pulse, but not enough to get them to open, instead just quietly buzzing for about a second. Is this normal? We don't have a scope in the workshop, but with the multimeter connected the injector generated approx 5.6v while pulsing via ddt4all (not a reliable measurement as the output was pulsing)
Are you 100% sure that the cam timing is right, you could have one of the cams 180 degrees out, don't ask me how i know The engine still turned over by hand and it didn't catch the valves, just saying.
I've not used the injector test on DDT4ALL, but I would have expect it to fully open for a short period. But only speculating. Just to clarify, the test was done for each individual injector one at a time, full battery or charger connected, and the same result for all 4 injectors?? Unfortunately using a DVM doesn't tell you much. I've attached the voltage signal I did a while ago as a reference on my RS250 at idle. I'm super impressed with the Owon hand scope - great value for the price. Also I've attached Renault resistance measurement guide - it may help. Maybe worth considering in addition to measuring resistance at the injector, disconnecting at ECU end and measure resistance thru wiring. This is not ideal as a poor/high resistance joint may not be detected with low low current flow of the multimeter - possibly need to do a higher current continuity test of the circuit using a higher wattage lamp. Should you have a bad earth connection maybe your previous test have shown up to be ok for low multimeter impedence tests, but that only shows up as a resistance when higher current flowing for a firing injector. Same goes for the hot side (ie 12v) of the injector supply - ie you could have a high resistance joint from the Switching Protection Unit (1337) & fuse, or the inline connection E3FB1-1. So not giving sufficient voltage to fully open. details how to do these tests. Could also be the ECU outputs, but you would think unlikely for all 4 outputs to go R/S holding you out of a start. All speculation on my behalf - so sorry I couldn't be more specific On the flip side if the DDT4All injector forcing as you witnessed is correct, then not getting any injector firing when trying to start may be due to the ECU stopping starting, ie interlocked out. Never thought of fuel being cut off to the engine due to a crash as per Ian's post. I had a look into PyRen and couldn't find anything obvious. I did find the attached page which stores if an "impact was detected" in the ABS ecu. May be worth seeing what your ABS has stored if you don't have any luck with finding a high resistance joint.
From memory when I checked the ABS side that there was no stored impacts, up until the cambelt failure the car was 100% original and daily driven, on this side of things if it was a impact lockout I would have expected the fuel pump and coils to have been shut down as well but they're running just fine. The possibility of the injector hot side being weak is on my list, it tests up OK for voltage but a poor connection along the line could be limiting the current, might try bypassing it and re-running the injector test. We tested the injectors both ways, with all connected, just one connected and with none attached. When measuring the resistance between the ground/trigger circuits between the injector plugs and ground we weren't able to get the meter to provide a value at all which was interesting. Also ran a 14.7v feed into the car just in case it was a low voltage issue with no change. We really appreciate your help here, we're closing in on the problem now thanks to you. Might have to use this as an excuse to buy a scoping meter :-)
In your email you said "between the injector plugs and ground we weren't able to get the meter to provide a value" Not sure what you exactly mean and whether or not it's a problem. The earth is switched on to the injector by the ECU to complete the cct - it does this thru a transistor circuit and only for 2 mS at idle. I don't think you would see any resistance - just an open circuit. Looking at the scope trace on my earlier post the measurement is taken on the injector wire that is connected to the ECU (ie switched earth or return). Just before firing, as there is no connection to earth (ie no current flow), this wire is at nominally 12V (ie same as other "hot" wire on injector). Soon as the ECU connects the injector return wire to earth current flows and the injector return wire drops to nominally 0V, and stays at 0V for duration of injector spray request. When the ECU switches the earth out of the return circuit, the current stops flowing and the voltage on the injector return wire eventually goes to 12V, but before this, for a very short time it spikes to 60-70V due to back emf. Out of interest have you run separate temporary earths from battery -ve to "injection" (ECU earth) "NH" to "ENH-A" connector? I've attached below a few screen shots from DDT4All with ignition on from my RS250 - it may help to compare. In particular the second one. Reason being, if you assume the response you got from forcing the injectors on proved the circuitry is good, it comes back to missing a permissive to enable a start. Also attached Renault's troubleshooting guide for injection fault codes; see bottom page 3 - for what it's worth
I was hoping my meter would have enough resolution to at least identify whether the ground side of the injector was switching when cranking, thus testing between the injectors ground pins and the battery ground - looks like a scope or scoping meter is on my buy soon list! Today I'll be bypassing the relay that provides the current to the injectors to determine if there is a hot side issue, we're getting the right amount of voltage so it's not at the top of my list of potential issues. Thanks for the injector pulse data, I've tested the ecu grounds for impedance, they all seemed ok, a bypass test will be on the cards though.
