Help! I could use some good diagnostic advice...

S

Sleeper

Member
Location
Central Texas
Car
2003 FX35 RWD
Hey Guys! I've mostly just searched for helpful info since I joined, but now I have a problem. My 2003 FX35 has always been maintained well. I only use Mobil 1, etc., and it has 130,000 all Texas miles on it. Last week my wife said it just died on the road. I asked if any lights came on and she said check engine light was on. I drove it after that and it shut down completely at 30 mph. I pulled off to the side of the road. The engine light was on, as well as the VOC?(looked like traction control light). Each time it re-started and made it back home but now the service engine soon light is on. So I have 2 specific questions.

1) Have any of you experienced this, and if so what was the cause?

2) What is a good diagnostic app and connector to scan codes on these FX's? (I know Snap On and other expensive scanners are good, but I'm hoping there's something pretty good for less than $50 if possible. I also have a laptop I can use for that if it is easier.)

I am extremely mechanical, just haven't had any problems with our FX until now. So I'm hoping fixing the problem won't be too bad once I find it. Thanks in advance for any help out there! -Sleeper
 
porkandbeans said:
Sounds like it could be a cam shaft sensor issue.

https://www.infinitiscene.com/search/1/?q=19379-Camshaft-Sensors
Click to expand...
Thanks, That's what my wild guess was too. I couldn't think of anything else that would instantly just kill it like that. After reading the other replies, I gladly bought the Torque Pro app. It also happens to be the most recommended app on a diesel forum that I'm on so that says a-lot about it's versatility. I put Torque Pro on a Nook tablet but I also have an iPhone and iPad that I can get OBD Fusion App on later so I found a fairly fast OBD2 WiFi adapter that will work with both systems. If anyone's interested, here it is: Veepeak Mini WiFi OBD2 OBDII OBD II Scanner Scan Tool Adapter Check Engine Light Diagnostic Trouble Code Reader for iOS iPhone iPad and Android

https://www.amazon.com/dp/B00WPW6BAE/ref=cm_sw_r_cp_awd_EHCixbVRKCYNF

It will be here Saturday so I'm going to scan for codes when it shows up and post back here. Thanks porkandbeans, your post is what led me to the iPhone compatible wifi scanner I found. And wind dance is right, the code scanners at Harbor Freight are really good repackaged name brand scanners, some with abs capabilities. I didn't want to spend $75-$125 on a code scanner/resetter when you gan do both and then have all the gauge/display/0-60/ 1/4mile and other live data for $22 total. I'll post codes Saturday, that's when I'll need a little more advice on what part and brand to buy from where, and someone to tell me where to locate the problem part under the shroud of plastic! Thanks!
 
It does sound like a camshaft sensor. Keep in mind that the left and right bank throws 2 different codes plus a another code for the crankshaft sensor. Good Luck
 
Sure sounds like camshaft sensor problem. I had that problem recently. Mine didn't cut out the the engine. It simply didn't start at random and got a trouble code indicating its the camshaft sensor.
 
Thank you all! You guys are the best. Good looking out WindDance, info like that is exactly why I'm going to report back here with the codes first! TorquePro is installed and all configured now for both of my vehicles, and working hard to establish a connection! Now, if that little wifi adapter would just get here....
 
Update: Active Codes Found

OK, so I just scanned and here's what came up on Torque Pro:

P0327 - Powertrain (Knock Sensor 1 Circuit Low Input Bank 1 or Single Sensor)

P0345 - Powertrain Camshaft Position Sensor "A" Circuit (Bank 2)

Any advice on these is appreciated. I read a few threads on CPS replacement including link posted above. I don't know what normal voltage of these or other sensors should be. I am pretty sure possible factory part #s are as follows:

CPS Bank 1 (Rear) = 23731-6J90B
CPS Bank 2 (Front) = 23731-AL61A
Crank.Pos.Sensor = 23731-AL60C

Please correct if necessary. I found both Cam Sensors (Delphi) on RockAuto for @ $40 each, and a high quality looking Hitachi Crankshaft Sensor for @ $45. They offer other brands so recommendations on what works or doesn't there are appreciated as well.
Note, these were read by Torque Pro. If any of you 1st Gen FX35 guys have any advice on custom PIDs or available plug ins that support these VQ35DE engines, that would be great too. I would like to be able to see EOT(engine oil temp), oil pressure, transmission temp, and as many other factory sensors as I can. Thank You.
 
P0345 is cam sensor on the driver side.
Very easy to do. Removal of the intake tube and throttle body gives you plenty of space to remove and replace the sensor. Word of caution the connector to this is a PITA to get off. I found using a good needle nose pliers on the tab to release it was the best way. Hitachi is the oem sensor, I just used sensors from pepboys/auto parts store.. Works just fine.

i would start off with the cam sensor with the battery disconnected and see if it clears the codes. Then proceed with the knock sensor if need be.

P0327 is a knock sensor short/low voltage.
Just because I like to research things! I think that this code is mostly thrown for a bad harness and not the knock sensor itself. Seeing as how cheap the sensor and the harness is, I would suggest to replace both. If you are handy and adventurous, a DIY would show you the inner works of the plenum of our vq35

Links to help you out
Cam sensor DIY thread (http://g35driver.com/forums/g35-coupe-v35-2003-07/370359-diy-cam-position-sensor-easy-version.html)
Knock sensor DIY thread (http://my.prostreetonline.com/2013/10/16/dtc-p0327-how-to-replace-your-knock-sensor/)
Knock Harness (https://www.z1motorsports.com/oxyge...5-vq35de-knock-sensor-sub-harness-p-5833.html)

GL!
 
Last edited:
Thanks, WD! Very helpful links. Are torque specs necessary for sensor mounting bolts? I have searched and haven't found them anywhere. I know the sensors have a metal sleeve in the molded plastic, so I'm guessing I can just snug the bolts down on them. I went ahead and ordered Camshaft Sensors for both banks, crankshaft sensor, knock sensor, and wire connector. The problem with being skilled and adventurous is I'll end up polishing the entire plenum if I remove it! Wife calls it OCD but I don't consider it a disorder most of the time!
 
According to the manual the torque is 86 inch-lbs. O-ring should be replaced and lubed with oil. My FX35 was doing similar but didn't throw any codes, can you remember yours cutting out at all before the incident that threw a MIL??
 
bigkinglow said:
According to the manual the torque is 86 inch-lbs. O-ring should be replaced and lubed with oil. My FX35 was doing similar but didn't throw any codes, can you remember yours cutting out at all before the incident that threw a MIL??
Click to expand...

TY, BK. That 86 in.lbs. spec, was not only super helpful to me, but to whoever else stumbles upon this thread! Most people would just bolt them on there, but correct torque and oiled o-ring install can make all the difference. I know from maintaining and tuning other vehicles, that you don't want to over torque and crush any o-rings or under tighten and risk sensor and o-ring vibration. I have also seen cases of oil loss due to bad sensor o-rings or installation even where the sensors were working fine. In this case, I'll be lining the o-rings with Mobil1 because that's what I use in the car. Because this car is my wife's daily driver, it is a little harder for me to know if there's a problem right away. I usually get vague descriptions of issues (with sound effects)! So apparently, there were 2 random instances with no start 1st try, then started 2nd try, spaced about 3 weeks apart. The check engine light came on then went back off after the second time (according to wife). She doesn't know much about mechanics, but in her defense, CPS sensor related problems can be very erratic and I do know of some cases where engines just shut down without warning.

If anyone is interested, on other vehicles I have tested Hall effect sensors from different manufacturers for the same vehicle. The simplest testing involves checking the strength of the magnets. An easy way is to see what size sockets each will lift without dropping (or washers, bolts, weights, etc.). The other tests involve sanding the plastic off the end of the sensors to see how good/bad the magnets are centered in the mold. We have also tested for what distance the end of the magnet is located from a fixed location (like where the sensor seats against the engine block). This may seem insignificant to some, but really good CPS and other sensors can make an engine run much better than "average". On my turbo diesel, I upgraded to one recommended CPS with a stronger magnet that's perfectly centered and it noticeably smoothed out the engine, and improved efficiency. In that case, I also had to put wire chokes around the (intermittent) wiper motor wires to prevent interference from affecting the more sensitive CPS. Other gear heads have also reported their belief that certain utility/communications related features that they regularly drive past emit some kind of temporary interference that causes their car to run poorly. I haven't experienced that but I wouldn't rule it out either.

I ordered both cam sensors, crank sensor, the knock sensor and the replacement for the problematic knock sensor wire. I am planning on using wire loom to protect that wire in case it makes any longevity difference. I know that replacing one sensor may have caused both listed codes, but I'm replacing all because I just don't want my wife and kids stranded somewhere. I will be testing the extra sensors I remove and keeping any good ones for future emergencies. The other thing I always do is clean existing sensor plugs and pigtails with electronic parts cleaner and allow to dry before plugging into new sensors. When I remove the factory sensors, I will at least test their magnetic strength against the replacements and note any differences from the replacements. Cheers!
 
Update: Just replaced both cam sensors. Bank 2 was the problem though. No MIL lights, no codes present. Flattened/hardened o-rings were slowly leaking oil down the back of the engine causing some burning oil smell that my wife had mentioned. You can see what's going on back there using an extendable/adjustable mirror with a LED light built in to the mirror housing. I bought one from Sears/Craftsman a few months ago. I cleaned out the throttle body/intake while I was in there. Running great now. I only had a 1 hr. window to work on it today so this weekend I will be replacing the crankshaft sensor, knock sensor and wiring adapter. I'm also going to check real good for any other leaks while I'm at it.
The original (angled) Bank 2 driver's side sensor that failed had just enough magnetic strength to lift a 17mm 3/8" socket. I used Standard Motor Products - Intermotor #PC461 to replace it. Same went for passenger side (straight) Bank 1 and used SMP- Intermotor # PC460. Strengths of magnets were all identical too. In case it helps somebody, the push/pop connector plugs were a little difficult at 130K, but not as bad as I thought. The passenger side was more difficult than the driver's side because the green button faces down. If anyone is struggling to remove the plug,just remove the sensor mounting bolt and pull out the sensor so you have some room to get it unplugged. Lube the new o-rings and push the new sensors in until they sort of pop into place. The back of the head castings have raised mating surfaces that match the shape of the sensors. You can rotate them and feel when they are aligned with the bolt hole. Thank you all for the help and details!
 
You must log in or register to reply here.
Back
Top