Fault codes and scan gauges

[the_bluester]

Well, the unfortunate has happened and my wife's 550 has thrown a CEL. I have searched a fair bit without success, is there any way to get flash codes to find what code is behind the light coming on?

The one thing I can tell is that it is down on power at low RPM, like it is really really laggy then at about 2000 RPM it lights up and goes like normal so obviously the turbo is OK, it looks likely to be either a boost control issue or I wondered about an EGR fault. Applying vacuum to the actuator moves the control lever for the VNT so the actuator itself seems fine. When first started, the vacuum from the vac pump moves the lever as well so presumably the solenoid is OK too.

Am I wasting my time looking for a way to get flash codes? If so, have people had success with the Scangauge 2 on the 550? If I have to I will go out and buy one tomorrow but I would hate to buy one and find it does not read codes or clear CEL on the car.

If this turns out to be EGR related, hopefully my race cars tuner is able to flash the ECU and "Ahem" fix the problem.

 

[the_bluester]

As well as the scangauge, would one of the to below be a better option if I do not care about live display of data while driving?

I don't care about the display, if I want that I will make an OBDII patch cable and dump an OBD config on my Motec dash form the race car to have a look.

https://www.fueleconomysolutions.com.au/icarsoft-i903-obd2-scan-tool-for-nissan-infiniti-s

https://www.fueleconomysolutions.com.au/carecar-aet-i-retail-obdi-obdii-scan-tool-for-niss

 

[the_bluester]

Bought a reader, 0488, EGR volume control valve.

Hopefully removal and a clean out on the weekend sorts it. The performance is sort of consistent with the valve sticking open. It does not sound as crisp as it used to when the ECU cycles it on shutdown either.

 

[blackpete]

I have a stx550. egr replaced at 52000 under warranty . I purchased Autel AL619 and it works perfect live data abs and air bag etc. I did change the coolant about 6mnths ago and didn't bleed egr cooler lines and it said insuffient egr coolant flow rebleed hoses cleared code all ok. sounds like youre valve may be stickey or faulty. You can buy new one on ebay for about $500.

 

[the_bluester]

Hopefully just sticky, I will find out this weekend. If so it will get a tune shortly and have the issue fixed up properly at that time. I ended up with the better spec SP tools one, it did the job. I plugged it into my mothers Dualis as well (Which I have serviced for about 5 years) which had no stored or pending codes at all.

One thing that was interesting is how far off cal the speedo is, it has always been very optimistic, a test run today says that at an indicated 100kmh the CAN data going into it says 92.

 

[Old.Tony]

^ I've pointed that out numerous times in the past.

The ECU knows quite well how fast the car is going and is probably sending a reasonably accurate voltage to the speedo to deflect the needle enough to indicate the correct speed.

However, Nissan's guidelines are to follow ADR, which says "Cannot read under actual speed, but can indicate up to 10% + 4km/h over". So at an actual road speed of 100km/h, your needle is NOT allowed to indicate 99km/h, but can indicate up to 114km/h. If it reads 115km/h it breaches ADR and Nissan have to calibrate it. If it reads 99km/h it breaches ADR and Nissan have to calibrate it.

'Calibration' for Nissan is the same thing as "make it comply", so if you're doing 100km/h and your calibrated speedo now reads 110km/h, congrats you just got trolled by your own car manufacturer.

That's why I use a GPS.

 

[the_bluester]

Actually it won't even be a voltage sent which is even worse, the speedo needle is driven by a stepper motor so it could be made to read exactly what the system is reporting as easily as read high.

 

[the_bluester]

Well, pulled the EGR valves out and cleaned them, no obvious visual faults (Except for the EGR hole in the manifold being choked up to about a third of it's normal size with carbon)

Put it all back together and cleared the codes, no codes and normal performance driving it around for about an hour.

Sent the wife off for the school run in it this morning, BAM, laggy performance and no power under 2000RPM. When it stuff up you can't hear the turbo beginning to spool up like normal as you first apply the pedal to it, I reckon the main EGR valve (The one that is a ******* to get to) must be sticking open.

I will have to read codes again tonight, just a pity that with all the possibilities, they have to lump half a dozen possible faults together under one code.

 

[the_bluester]

On a related note for testing. The fault code is quite generic and I think either valve used for EGR could produce the symptoms. That being the actual EGR contol valve tucked up in the valley or the throttle control valve used to produce some manifold vacuum to assist EGR.

Does anyone know of a vacuum/boost line that is on the cars that goes to the manifiold AFTER the butterfly? I would like to hook up a pair of boost gauges to the car, one before and one after the butterfly valve. If there is a pressure drop across the valve when the lack of power is evident then the valve is not opening when it should and the fault is likely to be there. If boost pressure is low but the same on both sides of the butterfly then the EGR valve is not operating as it should and is bypassing exhaust back to the inlet, limiting boost. Given the cost of either valve I don't plan to just throw money at it until the problem goes away.

 

[Old.Tony]

I'm pretty sure the 550 had a flow sensor, so you can't block the EGR without flashing the ECU to remove the flow check - and if you're going to do that, you may as well remove EGR open commands as well as exhaust stroke injector open commands (unless yours has a 7th injector).

I don't know the intake manifold of the V6 well enough, sorry. Can't help with the sensor placement.

 

[the_bluester]

I don't think they have the extra injector commands in the Aus delivered ones, they don't have a DPF.

I will blank the EGR on the car as fault finding to see if that sorts the performance issue (Knowing that it will result in an EGR flow code) If the performance is fixed then I will at least know it is a problem with the EGR valve itself and can act accordingly.

I have a copy of the FSM so I looked up the current code in that, generic info on the code on the net is mixed, one says "EGR system performance" Another says it is a fault in the EGR volume control valve, but the Nissan info calls that code an EGR cooling circuit fault so I will have to go chasing air in the system. I did spend quite some time chasing down air until I could not find any more but presumably there is some left. There is a coolant loop in the EGR valve so I took that as the chance to renew the coolant (It was due)

 

[Old.Tony]

The extra commands are for the CAT. It needs a hydrocarbon as a reductant for the platinum and palladium/rhodium which act as the catalyst to remove the NOx. Vehicles were just using the fuel (because both petrol and diesel are hydrocarbons) but some are starting to use AdBlue (urea, yes, that's urine - and water). Water turns to steam (keeps it clean) and the urea is a hydrocarbon (NH2CONH2). Not as dense as diesel (C13H23) but cheaper to produce and isn't a fossil fuel.

 

[the_bluester]

To be honest, I don't have much of a problem with the cats, they are a relatively trouble free technology unlike EGR that has a comets tail of stories of woe following it around. I would sort of prefer Adblue to using fuel as the reactant. I was thinking by extra injector pulses you were meaning DPF regen.

Now there is a thing, if they are going to have all this tech on the cars like EGR and DPF, why don't they take the EGR source from the post DPF exhaust stream? It would need less by way of EGR cooling and would contain far less particulate matter to stuff up inlet tracts. Now that they are using inlet restricting butterflies to increase EGR flow, taking it from a low pressure area in the exhaust would not be an issue.

Going back a step, there does not appear to be any EGR flow sensor on the V9X, I reckon it is measured by monitoring the induced manifold vacuum and possibly AFR and inlet air mass by way of the MAP sensor, O2 sensor (Presumably wideband) and MAF sensor.

 

[the_bluester]

On a related note, does anyone have information on what PIDs you can fish out of the STX-550 OBD port?

I am thinking if enough useful information can be pulled out I might make a patch cable and take my race cars data logger for a drive to see what is going on internally. Surely Nissan have access to deeper data than just rpm, manifold pressure, water and air temps etc.