Independent Renault Forums banner

21 - 25 of 25 Posts

·
Registered
Joined
·
24 Posts
Discussion Starter #21 (Edited by Moderator)
A few more euros spent and the problem continues. More and more I believe that it is an electrical / electronic problem.
I followed a friend's advice and tested the egr valve and its connections (please see attachment).

All tests were positive except for the following:

"Checking the EGR signal from the controller
• Plug connected
• Engine at operating temperature and running idle
• Measure the voltage between pin 1 and pin 5. Nominal value: 0 V when idle
• Operate the accelerator and when doing so, the voltage must increase. Nominal value: Up to approximately 5 V If the nominal value is not reached, troubleshoot according to the electric circuit diagram supplied by the vehicle manufacturer. "

I can have the 0 vlts idling, but when I press the accelerator pedal the voltage goes up to 13 V.

With the van in movement it oscillates between 0 and 13vlts.
It is a renault kangoo 1.9d of year 2001 with the engine f8q.

Could the ECU or the wiring be defective? or obtain values above 5 v is normal for this model?
Thank you

Document deleted, Forum Copyright rules apply
 

·
Super Moderator Technical Supremo Platinum Member
Joined
·
24,226 Posts
Not sure where the 5v value comes from...though as it is shown in the manufacturer's technical information one has to suspect they know what they are talking about.
From what I know on them, they are solenoid operated, full open at 12v (nominal) and this is the normal test across pins 1&5.... does it open with 12v across them and shut smoothly when removed.
I also know they open and close rapidly and often, look at vacuum operated version and they move like a fiddler's elbow, it is not open or close, it is moving all the time.
I also know that the 12v is electronically switched and guess it may be a pulse modulated signal (as the glow plugs and pump pressure regulator are).
If the guess is correct, then some meters give a false signal on DC volts, reading peak not modulated and may not be giving a true picture (seen this many times on glow plug voltages).

With regard to your problem, I don't think it is the EGR.
But pull the plug and run without it operating...you will get an error signal on the dash but it should not affect running or put you into limp mode.
If the car runs without the erratic idle issue, worth digging deeper into the EGR.
I suspect it will have no difference though.
 

·
Registered
Joined
·
24 Posts
Discussion Starter #23
DancingDad, thank you very much for the answer.
I already tried to disconnect the egr plug and nothing happens. The only sensors that, when turned off, make the idle stable, are the coolant temperature sensor and the speedometer.
The point of testing the Egr valve is that is the only sensor that i have a test scheme to help me to find a possible problem in the ECU or in their wires.
EGR opens and closes well with the 12v supply. The point is that the ECU with the engine at normal operating temperature and according to the test should manage the voltage that supplies the valve with 0v at idle and up to 5v when accelerating ... which is not the case. Which leads me to believe that the values above 5v make me think that there is really a problem with the ECU or the wires that connect it to the sensors.
I can't find a good car electronics technician in my area of residence and I'm basically i´m paying to everybody give me opinions. I've spent more money than the van is worth. But i like the van and i liked to fix it.
I needed to get some more test schemes for the sensors to verify and prove my theory.. or not.
I am also thinking of purchasing a car diagnostic machine to help me find the problem..
 

·
Super Moderator Technical Supremo Platinum Member
Joined
·
24,226 Posts
Ignore the 5v
This can simply be meter "error" as I explained in previous post.
If the engine is running the same with EGR disconnected, that is not the problem.
And will likely not be indicative of any issue with the ECU or wiring not associated with the EGR.
TBH, you are in danger of overthinking this and falling into the trap of blaming the bits you cannot test, common is ECU, amazes me that so many anecdotally fail but we rarely see it on here. For my money, they are the least likely part to fail in the whole engine management system.
The problem you have is finding what is failing.
We can give some guesswork, based on experience and some logical thinking but it is a guess.
Mine is still the coolant temp sensor despite you already swapping it.... could be a wire or connection?
What I cannot make any sense of is the speedo disconnected.... except that may force the ECU into "default" settings so it is ignoring some sensor inputs, including whatever is causing your issue.
 

·
Registered
Joined
·
14 Posts
Sorry to butt in your thread. I have the 1.5dci engine 90bhp version. When you say you have irregular idle, do mean like a high frequency vibrational rate through your steering wheel, drivers seat and pedals? If so, I'm too experiencing the same symptoms with my engine at idle.

Mines on 59k. I've changed the clutch, whole suspension arms, links, shock, top mounts, along with the common fuel rail, maf sensor. I've done a full service. Still the car vibrates on idol.

I've cleaned the EGR, nothing seems to fix my issue. I changed the coolant sensor and the new sensor seemed to have an issue which kept telling my ecu that my coolant was running cold, even when the engine had been on a run. So I had to switch the old sensor back to get the blue temp light to go off.

As Dancingdad mentioned. I believe we are chasing something that could be well out of the range of parts your considering on changing.

I've changed my fuel filter twice in the past 12 months, and I changed the common fuel rail thinking it could be down to that. I've got a renault captur, so I know we both have different engines. But my problem sounds similar to yours. So I'm keen to find the answer to both of our issues.
 
21 - 25 of 25 Posts
Top