Greetings all,

I've run into something new with my '02 Q45. I just got P1140 ( INTK TIM S/CIRC-B1) and P1110 (INT/V TIM CONT-B1).



Reading up on these codes, I see that the Vehicle Speed Sensor has something to do with it somehow. I've swapped out my diff to a '05 350Z diff. There's a huge difference in the gearing, of course. So when I'm running around 85+ MPH on the freeway, and the RPMs are in the 4,000+ range, the speed sensor tends to throw a DTC.

Could this also be causing the Valve Sensor and Valve Timing codes I've got?

I also recently went from 5W-30 to 10W-30 which per the owner's manual is still within spec. Seeing as I'm revving higher all the time now, I thought the heavier weight oil would be better. I've also read that 'dirty' oil could cause the Valve Timing part to get stuck, as it uses oil to control valve timing hydraulically.

Any insight would be greatly appreciated, as always!

All the best,
~HollywoodJackson~

mac , do you log every maint./ mod/repair ? If so trying to nail down just WHEN codes came up to help point to they're timing & connecting to an "action" you performed. And we all drive along and it is tough to connect these things when they happen once in a Blue moon , or when many "things" are done at once OR fairly close together in time.The 5 to the 10-30 seems like a sound decision , my opinion not probable connection there.

Remove the sensor, wipe it clean.
Make sure your oil level is correct.
Switch the sensor with the bank 2 sensor to see if you now get P1145 &, or P1135

EdBwoy wrote: ↑

Sat May 05, 2018 4:06 am

Switch the sensor with the bank 2 sensor to see if you now get P1145 &, or P1135

So I did getP1145. It seems the sensor is definitely bad. Also, I noticed a lot of oil pooled under the intake on top of the motor. So that would mean my valve cover gasket/s is/are shot?

Thanks EdBwoy!

macgiver wrote: ↑

Fri May 04, 2018 5:27 pm

do you log every maint./ mod/repair ?

I'm trying to keep an accurate log of every mod, yes. So far it's just coilovers and the 350Z differential.

You're welcome H.J.
About the oil pool, got a picture? There should be no oil in the Vee. VC leaks are usually slow enough and follow gravity to the outside of the engine. Drip down the headers and onto the exhaust.

Maybe you're seeing water if you ever wash your engine Water which should disappear by evaporation.
But I'll think about it some more. This is that area under the lower intake collector, where the knock sensors are, correct?

I took pics I can post when I get to the house. Yeah, it's pooled in the V right below the intake. The V is pretty deep too.

Hey EdBwoy,

Here are the pics showing where I see the engine oil pooled (puddle) on top of the engine. It's not as much as I thought it was, but it's there. Maybe 1-2 centimeters deep just sittin' there... Where the tip of the magnet tool is resting down under the intake.



All the best,
~HollywoodJackson~

Well, I'll be damned!
I don't doubt you, could you send some fabric down there -a white rag or paper towel to ascertain the color of the fluid?
Red being trans, power steering and hydraulic fan fluid.
Either way, I can't quite picture how any of those fluids or engine oil would end up there, in that quantity.
Coolant, maybe. There is some plumbing down there.

EdBwoy wrote: ↑

Tue May 08, 2018 10:04 am

Either way, I can't quite picture how any of those fluids or engine oil would end up there, in that quantity

I'm almost certain it's the fan fluid. I had a really bad fan fluid leak a few weeks ago. I think it was leaking down the fitting, and some of it was finding it's way to the top of the engine, under the intake.

It doesn't smell like motor oil. It does sort of smell like the fan fluid. It's been frying on the engine for weeks, so it doesn't smell exactly like the fan fluid, but close.

All the best,
~HollywoodJackson~

If I didn't know better I'd be laughing at "fan fluid" - right next to the "blinker fluid"

That was a unique way of fan control for a couple of years.

Hey EdBwoy,

I purchased a Cam Pos Sensor from AutoZone... And installed it. 1, it wasn't shaped right. It was difficult to get it in the bank 1 position because the plug is at the wrong angle. Really tight fit. I swapped the sides again, and while there is plenty of room on the bank 2 side, it still wasn't a good fit as the wires were BARELY long enough to reach the plug. Well... The new AutoZone sensor STILL threw codes.

I took a Cam Pos sensor from a 2003 Q45. Same weird angle. And instead of being all black and plastic with flat sides, the '03 sensor was metal and round like a cylinder. The '03 did had longer wires. Anyway, I installed the '03 sensor, and still got errors on the side it was on.

I said screw it, and put the original '02 Cam Pos sensor back in, for now.

~HollywoodJackson[/b}~

Your problem might be something else entirely.

Have you ever come across this video, and gone through the link in the description? It might help clarify the sensors and why some fit in various ways.

Hey EdBwoy!

Apologies for the confusion. Doing too many things at once this morning!!

My issue stems from the original code that was the VVT sensor. Bank 1 code was for the VVT sensor, with no codes for Bank 2. Upon swapping sides of the VVT, I got different codes for Bank 2, none of which were the VVT (and no codes for Bank 1).

I think my problem is the 1 VVT sensor and/or the fact the diff is resulting in parameters out of range for the ECU to cope with...

Thoughts?

All the best,
~HollywoodJackson~

HollywoodJackson wrote: ↑

Sat May 05, 2018 10:59 am

EdBwoy wrote: ↑

Sat May 05, 2018 4:06 am

Switch the sensor with the bank 2 sensor to see if you now get P1145 &, or P1135

So I did getP1145. It seems the sensor is definitely bad...

But you did get a VVT code up there, right? P1145 is a VVT code.



How about we start again from the top? What codes did you have, what actions did you take, what codes came/ disappeared after the action.

On sensor shapes & configurations:
The picture should show you what the sensors should look like, and if you get aftermarket ones, some of them are the metal cylinders rather than the oblong plastic cylinders.
I'd still recommend you take some time to watch the video and read the thead linked in the description. Somewhere in there the different sensors are compared.

EdBwoy wrote: ↑

Wed May 16, 2018 8:12 am

How about we start again from the top?

Good idea.

First codes:

• P1720 Freeze Frame
• P1140 (bank 1 code)
• P1110 (bank 1 code)

Swapped VVT sensors from one side to the other (Bank 1 to Bank 2)
These:


After swapping sides, clearing the codes, and driving, when the codes came back, it was a bank 2 code:

• P1720 Freeze Frame
• P1145

I went to AutoZone and bought a replacement sensor. It looked just like this:


Installed it, with some trouble, because of i\ts different shape. The wiring was BARELY long enough to reach it. Cleared the codes. Drove. Codes came back, associated again with the side the AutoZone sensor was on. I couldn't swap it back to bank 1, because there is some other wiring in the way making it impossible to install due to its weird shape. I returned it to AutoZone.

Next I found VVT sensors, same place on the engine, on a 2003 Q45. I noticed it had the same different shape as the AutoZone part. I took it anyway. It looked like this, just as you said, with the metal cylinder:


After installing, I cleared the codes, drove, and bang! Codes for bank 2, where the replacement sensor again was. Every time I get a code, P1720 Freeze Frame pops up. I did a little research to see what Freeze Frame meant. Apparently, it's the most serious code you have in comparison to what other current codes you have. And in the FSM P1720 is listed to be relative to the functioning of the VVT system. The ECU uses data from the VVT sensors and the Speed Sensors to dial in the variable valve timing.

The only sensors I've touched thru the whole ordeal are the two IVT sensors. I do think one of the IVT sensors is a little shaky. However, I think the main problem is the swapped differential gearing being so different. The vehicle's speed sensors are giving data way out of wack and the ECU is thinking "something must be really bad to get data this far outside of allowances".

For example, the sensor at the transmission says wheels should be spinning at x3 rate of speed, while sensors at the diff are saying the wheels are spinning at x2 rate of speed, and at the same time the engine RPMs are out of wack as the car is revving at higher speed due to the new diff gearing ratio.

This is what I am "thinking" is the issue. And I also know I have very little experience, so, I am open to any more seasoned ideas. By the way, I did watch the video. It's a great video!

All the best,
~HollywoodJackson~

P1140 (bank 1 - left), P1145 (bank 2 - right) because an excessively high or low voltage from the sensor is sent to ECM. Could be due to:

• Harness or connectors for the IVT circuit
• IVT control position sensor
• crankshaft position sensor (POS)
• camshaft position sensor (PHASE)
• accumulation of debris to the signal pick-up portion of the camshaft

I'd like to call attention to this again

Swapped VVT sensors from one side to the other (Bank 1 to Bank 2)
...I went to AutoZone and bought a replacement sensor.
Installed it, with some trouble, because of i\ts different shape. The wiring was BARELY long enough to reach it.
...Next I found VVT sensors, same place on the engine, on a 2003 Q45. I noticed it had the same different shape as the AutoZone part. I took it anyway...

In the video, for about 2.5 minutes, starting at minute 07:00 I demonstrate the difference in the sensors and why it is important to get the correct sensor. Will they be functional in the "wrong" locations? Probably, but fitment might be very tricky.

1. First codes: P1720, P1140, P1110
2. Swapped VVT sensors from one side to the other (Bank 1 to Bank 2)
3. After swapping sides, clearing the codes, and driving, when the codes came back, it was a bank 2 code: P1720, P1145
3. I went to AutoZone and bought a replacement sensor.
4. Installed it, ...Cleared the codes. Drove. Codes came back, associated again with the side the AutoZone sensor was on... I returned it to AutoZone.
5. Next I found VVT sensors, same place on the engine, on a 2003 Q45. I noticed it had the same different shape as the AutoZone part. I took it anyway. (someone probably used the wrong sensors)
6. After installing, I cleared the codes, drove, and bang! Codes for bank 2, where the replacement sensor again was.
7. Every time I get a code, P1720 Freeze Frame pops up...

A few questions here:
- with all the wire movement and related trouble, are you making sure the wiring or harness isn't damaged? Also, are you ensuring the terminals are clean and clear and that the plug clicks when you connect it?
- What happens if you put the original bank 2 sensor back in its position?

- Between #1 and #3, the code seemed to follow the sensor
- From #4 to #9 the issue seemed to stay at the bank.
What I'd do is try to switch the IVT sensors again to see what comes up. Check for debris, confirm your oil level is good.
How many miles does your car have? Since you're having luck returning sensors, replace the camshaft sensor then maybe the crankshaft sensor. [I recommend you make one change at a time, to know what is actually effective]

The only sensors I've touched thru the whole ordeal are the two IVT sensors. I do think one of the IVT sensors is a little shaky. However, I think the main problem is the swapped differential gearing being so different. The vehicle's speed sensors are giving data way out of wack and the ECU is thinking "something must be really bad to get data this far outside of allowances".

For example, the sensor at the transmission says wheels should be spinning at x3 rate of speed, while sensors at the diff are saying the wheels are spinning at x2 rate of speed, and at the same time the engine RPMs are out of wack as the car is revving at higher speed due to the new diff gearing ratio.

This is what I am "thinking" is the issue. And I also know I have very little experience, so, I am open to any more seasoned ideas.

P1720- vehicle speed sensor because ECM detects a difference between two vehicle speed sensor signals is out of the specified range. Could be due to:

• Harness or connectors for the CAN communication line
• Harness or connectors for the revolution sensor circuit
• Harness or connectors for the wheel sensor circuit
• TCM
• VDC/TCS/ABS control unit
• Combination meter

I think the IVT codes are exclusive to your P1720, but these are new frontiers to most of us here. What I can see from the manual is that the only trigger for the IVT system is 2,000 rpm. After all, if the P1720 was triggering the IVT codes, wouldn't you expect it to happen to both banks?
I might need to revisit later with a new focus. I might be functional, but I don't know if I am sharp enough to launch the space shuttle at this hour on a Friday night.

I think it would be important to get This question answered like I had asked in the other thread (btw, I don't know why I couldn't find P1720 at that time). Since only the 2 of you are currently reporting such issues after making that change, maybe it is something to do with your diffs. Size matters, and as shown above, if the ABS system (reading codes from the wheels) is returning readings way out of pre-programmed range compared to the transmission output, then such a discrepancy would pop the code.

EdBwoy, thanks for this detailed reply!

I will work on this, this week, and post my findings.

Good afternoon/evening everyone following this thread. I have news... CEL is OFF!

Thanks for all of the great information EdBwoy!

Took the two IVT sensors off another 2002 Q45. Swapped one of them in for the bad one on Bank 2 that's been causing my codes.

Regarding the speed sensor code I've been getting, which I'm pretty sure it's due to the diff swap, I simply disconnected the speed sensors, one at each front wheel.

I cleared all codes using OBD-ii. Since, I've put several hundred 'spirited' miles on the car, freeway and street. No more codes! CEL has remained off.

Now, TCS ABS and SLIP lights are on. LMAO. That's okay though as it's because I've unplugged the speed sensors at the front wheels. I want the car to be able to drift. Not all the time however. My next mod is going to have to be installing the toggle switch allowing me to turn the yaw sensor on/off at will, which in turn renders TCS and ABS completely disabled. I have the write up for this mod for a Y33. I still need to confirm that the wire to be tapped is the same as on the F50.

By the way, my Q45 has 203,000 miles, and it runs like a champ! It's got big balls, to be honest. A lot of car for the paltry price I paid 3 years ago. And the only maintenance problems to date have been...

1. Plastic housing at top of radiator cracked (replaced just the plastic piece)
2. Water pump no longer pumping fan fluid (replaced)
3. Fan pump fluid leak (replaced an o-ring)
4. Air relief valve in hose to heater core failed (replaced)
5. OEM front struts failed (replaced with coil overs)
6. Driver's seat frame broken (replaced)
7. IVT sensor failed (replaced)

I'm extremely happy with this car!

All the best,
~HollywoodJackson~