So I've been trying to diagnose a DTC that's been coming on intermittently on my 2001 Infinity QX4 (in case you are wondering its P1130: Swirl Control Valve Control Solenoid Valve). I replaced the troubled part last week and the CEL came on again, so either I got a bad part or there is some other source triggering the CEL. I'm going to piddle around under the hood this weekend with a multi-meeter to see if I can pin-point the issue and make sure the ECM is sending the correct voltage to the solenoid. Anyway, to assist me in the diagnosis I was thinking about purchased some OBD-II software to load on my laptop. I'd rather spend a couple hundred buck on a good tool then for a diagnosis from the dealer. With and initial search I've identified a few candidates and was hoping to get some feedback, reviews and recommendations form you guys.

AutoTap Express - $149.99 (hardware and software package)
http://www.autotap.com/product.asp

ProScan - $129.99 (hardware and software)
http://www.myscantool.com/

AutoEnginuity's Scan Tool - $249.99 (hardware and software)
http://www.autoenginuity.com/products.html

2/4/2011 10:20:28 AM

For what you're trying to do, I don't see how the abillity to graph coolant temperature and other generic loggable parameters will help you. They look like they have slightly different dongles and software, but they are all limited in the sense that they can only log universal OBD II parameters at the mandated 5hz sample rate.

Since this is a manufacturer specific code, the first thing you need to do is get a factory service manual for the car. I'm not sure if there are any free ones online (buried in some internet forum), but you can probably get it on CD/PDF form if you pay for it. You need to go through the diagnosis section to see how the computer actually triggers the CEL and what the recommended diagnostic procedure is. Alldata has some stuff but it's usually not on the same level as a real service manual.

For example, is that code triggered from an open or short? Or does it calculate a swirl valve position and determine that it's stuck? You may have to pull the manifold and actually clean the swirl valve because it's gummed up with carbon. The swirl valve on Nissan is similar to the tumble generation systems used on VW, Subaru, and others. Its mostly for emissions and fuel economy under certain types of low load conditions.

2/4/2011 12:50:38 PM

Quote :

"Since this is a manufacturer specific code, the first thing you need to do is get a factory service manual for the car. I'm not sure if there are any free ones online (buried in some internet forum), but you can probably get it on CD/PDF form if you pay for it. "

http://www.obd-codes.com/trouble_codes/infiniti/

2/4/2011 2:22:50 PM

Well the information I am talking about is more specific than what is found in that basic list. For example in the list it describes Nissan/Infniti code P1110 as "Intake Valve Timing Control (Left Bank)" which is rcorrect.

But when I pull up my Q45 factory service manual I get full diagnostic procedures and more information on how the code is triggered. Here is a sample:

2/4/2011 2:48:02 PM

yes I have a factory service manual and plan on doing some more troubleshooting this weekend following the procedure. the only reason I would get this software is if I can't resolve this issue with a multimeter and taking several readings under different operating conditions per the service manual. if i can't though, i'd rather spend the money on a new tool then taking it to the dealer. what i'm interested in regarding the OBD tool is reading and displaying freeze frame data, which is a snapshot of what your car was doing when an error occurred. i think that can be helpful if i can't diagnose it with a multimeter and applying voltage directly to the faulty solenoid.

the way i figure it either...

1. the new part is bad, which i'll be able to determine by applying battery voltage directly to the connector contact on the solenoid

2. there is a loose connection on the cable harness or the harness is bad which i will be able to tell with the multimeter

3. the ECM is bad which I will also be able to diagnose with the multimeter.

if anyone who is more electrically inclined them me wants to get under the hood with me Saturday afternoon (weather pending) and drink some free cold beer then you are more then welcome.

2/4/2011 3:49:17 PM

I've used freeze-frame data before. It's not as useful as you'd expect. You don't need laptop software to pull it up. I have an Actron CP9180 scantool which displays the data. It's the same one they use at Autozone/Advance/etc. I can tell you right now that a universal scanner isn't going to tell you anything having to do with the Swirl Control Valve. It will give you coolant temperature, rpm, throttle position, and whatever else is available from for that vehicle from the SAE J1979 parameter list. But that's not going to tell you much.

You're dealing with a manufacturer-specific parameter (there's probably swirl valve position data you can read). You need something that can read from the Nissan CONSULT data stream.

Quote :

"the way i figure it either... 1. the new part is bad, which i'll be able to determine by applying battery voltage directly to the connector contact on the solenoid 2. there is a loose connection on the cable harness or the harness is bad which i will be able to tell with the multimeter 3. the ECM is bad which I will also be able to diagnose with the multimeter."

One of those three may be it. When you've got a code like that, you start with two things 1) car specific internet forums, in the event that it's a common problem and 2) OEM diagnostic procedures if available. I've got a friend who is a dealership technician. If you take it to the dealer they are going to

1) immediately know what the problem is if it's common enough
2) check for TSB's
3) go through the factory-recommended diagnostic procedure
4) maybe call the tech line if they are stuck.

[Edited on February 4, 2011 at 4:48 PM. Reason : .]

2/4/2011 4:40:29 PM

thanks for the advice. i've been browsing the nissan/infiniti forums for a while now but the activity on those boards is no where near what i experienced with the bimmer forums. they haven't been that helpful.

so i spent part of sunday going through some of the diagnosis procedures and what it comes down to is i just don't have the correct tools to figure this out. i'm going to need to take it to a mechanic. it sucks...it equivalent to failure for me. I've had this truck for almost 4 years and have only have to take it in for service once and that was to get a key re-programmed. i've been able to do all the maintenance on this vehicle until now.

so i know its been asked before but any recommendations of a good nissan/infinity shop besides the dealer? happy japs?

2/7/2011 8:30:44 AM

Have you looked at the PLX Kiwi + PLX Logger (149.99 + 99.99)? The plx kiwi gives you PC connectivity with the option for expanded serial port devices AND the option to do monitoring and data logging from any iPhone or Android device.

2/8/2011 1:01:10 AM

did you try physically cleaning the swirl control valve? It could be gummed up with carbon.

2/8/2011 8:48:41 AM

i'll give that a shot

2/8/2011 9:09:32 AM

Just ordered this for my car, and some cheap ebay bluetooth adapter

http://torque-bhp.com/

total cost $30

2/8/2011 4:44:44 PM