Analyzing crank position sensor and cam position sensor capture on a B6304T

[Meatball]

We're really off into uncharted waters here Bob.

 

[Meatball]

I have no idea why I get such different results each time I capture. I mean, the PICO is obviously a better scope. Hands down. But even using the PICO, I get errata in my signals. The signals don't line up, etc. I'm pretty sure that it is because of the fact that I'm driving the cam sensors and the transducer through a bench top power supply. I've got it set at 5V and 4A exactly. Maybe I need to ground it to the block? Also, I suppose putting the lead acid battery on my charger would be a good idea too.

Anyway, I think that I now have enough information to move on. I'm sure someone with more experience could get better waveforms. I am trying... I have subscribed to the Mechanic Mindset diagnostic training course which is primarily focused on oscilloscope usage.

This is what I got after cleaning up all of the garbage:

 

[Meatball]

I already have the B6304T4 installed in the XC90 BTW. I also have the EMU Pro 8 completely wired. In addition to all of that, I have a RealDash running on a Raspberry Pi 4 to replace the DIM because I am sure that it was going to give me fit until I can get the CAN bus sorted.

Here's the link to the other thread with more info about the XC90:

Thread 'B6304T4 into P2 XC90'

Oct 24, 2025

Man, this was a really bad idea

• Meatball
• Replies: 20
• Forum: performance & modifications

 

[bobxyz]

I have no idea why I get such different results each time I capture. I mean, the PICO is obviously a better scope. Hands down. But even using the PICO, I get errata in my signals. The signals don't line up, etc. I'm pretty sure that it is because of the fact that I'm driving the cam sensors and the transducer through a bench top power supply. I've got it set at 5V and 4A exactly. Maybe I need to ground it to the block? Also, I suppose putting the lead acid battery on my charger would be a good idea too.

I think you have some of the scope probes set to INVerted, which makes your waveforms look different than previously.

Your latest waveforms are good enough to estimate the tooth #1 angle, and it's much different than the redblock 87deg or the MaxxECU 86deg. From the waves, I get about 270 degrees. It sure would be great if there were an actual spec somewhere for this. If you ever have the flexplate exposed, you could get closer by counting teeth and fraction of a tooth between the 60-2 gap and the tip of the CPS when at TDC.



How close are you to turning on the ECU and checking sensors? The next step after that would be to try the ecumaster diags and see if you get similar waveforms when cranking.

I'll take a look at the ecumaster cam/secondary trigger pattern options later today to see what best matches your intake cam waves.

 

[bobxyz]

_If_ I understand the EcuMaster cam/secondary trigger configuration options correctly, setting them up as "Longer than Factor" position mode, 1.40x, falling edge, should work correctly and should have both reasonable margin for cranking speed variations and for the VVT cam sensor timing shifts.

 

[OttoB]

That pattern is very similar to a B4204 MY2000-2004 cam signal. Took me a while to understand that camshaft is rotating at half speed...

 

[Meatball]

That pattern is very similar to a B4204 MY2000-2004 cam signal. Took me a while to understand that camshaft is rotating at half speed...

It's always 720° crank for each cam sequence.

 

[OttoB]

It's always 720* for each cam sequence.

Yes, it is easy forget when running a camless four-stroke

 

[Meatball]

Yes, it is easy forget when running a camless four-stroke

Rotary or direct valve control?

 

[OttoB]

Rotary or direct valve control?

Normal valves operated by hydraulic cylinders.

 

[bobxyz]

I rummaged around the web and found a cam/crank/pressure waveform capture for a B6324S5 3.2L engine. The B6324S5 is a NA engine in the SI6 family. It has cam profile switching (triple cam lobes for low/high lift), unlike the Turbo B6304T4 3.0L. At first, I didn't think the cam signals were the same, but after looking at it more, it seems like they match Meatball's B6304T4 waveforms.

From https://rotkee.com/en/wavebase/good...der-pressure-volvo-xc60-1-2008-2017?brand=203
"Vehicle: Volvo XC60 1 2008-2017 / Engine code: B6324S5 3.2L / Good timing
Camshaft and crankshaft correlation / CKP, CMP & in-cylinder pressure / Operation mode: VVT solenoids disconnected
Author's comment: BOTH CAMP PROFILE SOLENOIDS UNPLUGGED. INT VVT SOLENOID UNPLUGGED
Author: Pedro De La Torre / Signal was added: 9-apr-2020"

Fortunately, the pressure sensor in these waves has a pretty sharp peak:


Here's a zoomed in view from the website, with Tooth #1 reference lines drawn in:


From the above waves, the tooth #1 angle is 264 degrees, with accuracy of better than +/- 1degree.

[I also found a more detailed description of the various Volvo engines from sweedspeed, versus the standard wikipedia writeup:
https://www.swedespeed.com/threads/volvo-petrol-engine-variants.684005/ ]

 

[Meatball]

[I also found a more detailed description of the various Volvo engines from sweedspeed, versus the standard wikipedia writeup:
https://www.swedespeed.com/threads/volvo-petrol-engine-variants.684005/ ]

Bob, you have been more than helpful and I am extremely grateful for that. I am going to do my best to actually produce smoke from this thing today.

---

One last quibble and I am going to stop talking about the minutiae regarding the B6304S/B6304T.

From that article:

Unlike the 3.2-litre naturally aspirated SI6 engine, however, the turbocharged SI6 engine omitted the:

Variable Intake System (VIS); and,
Cam Profile Switching (CPS) system for variable intake valve lift.

The VIS system is actually related to the intake manifold on the B6304S. This is not VANOS. I will include pictures later.

It is true that the cam profile switching solenoids are omitted but the cam retains the extra lobes apparently. I mean, the only way to actually confirm this would be to disassemble the engine and I am not doing that (yet). VIDA shows the extra lobes. Online pictures show the extra lobes. I included a screenshot from VIDA showing the extra lobes earlier in this thread. The switching is probably just locked at one extreme. Again, a teardown would be the only way to confirm this.

---

Remarks like these only add to the confusion:

B6304T4 engine (2010 update)...
In May 2010, Volvo announced that it had upgraded its T6 engine...

A low-friction accessory drive belt tensioner;
Engine management software that was optimised for fuel economy;
An aluminium water pump housing.

The remarks in bold are related to each other and completely omit the truth of the matter (IMO). This is related to removing the power steering pump from the REED assembly and making it electric.

The pumps are both aluminum (B6304S/B6304T). There are absolutely NO discernable differences other than the fact that there is a pulley on the water pump whereas before; the water pump and power steering pump were integrated by a spring coupler and the P/S pump pulley drove the water pump.

I am sure that removing the P/S pump DID in fact result in a much lower friction on the accessory belt drive tensioner. But there is no discernable difference there either. I didn't cross check the part numbers so I will withhold full criticism of this point for now, lol.

---

For now, thank you very much.

I will report back later.

 

[bobxyz]

Best wishes for an easy 1st startup and initial tuning. If you try the EcuMasters crank/cam/vvt diags and wizards, please post a couple pictures showing how that feature works.

Back on the cam, it would be interesting to see if the Volvo part number is the same between the SI6 3.0 turbo and the 3.2 NA engines. I think this would be:
cam part # for 2013[?] S60 3.0L Turbo versus
cam part # for 2013[?] XC60 3.2L NA

 

[GTJordan]

SI6
Turbo
Intake PN 30750001
Exhaust PN 30750002

Non turbo (S and S5 engines)
Intake PN 30731249
exhaust PN 30731248

Non turbo (S2 and S4 engines)
intake PN 30759892
Exhaust PN 30731248

I absolutely would NOT trust the VIDA parts diagrams for any actual information. They will show generic or wrong photo's all of the time.

 

[GTJordan]

Here is some VIDA infor for Bob, just for curiosity.
Variable camshaft profile (CPS), only applies to B6324S5
The ideal engine should have low valve lift for low engine rpms and loads, and high valve lift at high rpms and loads.
To achieve this, an engine with two completely different camshaft profiles is required.

This engine has a patented system for camshaft profile switching. The system uses two completely different cam profiles designed on the same camshaft.
The inlet camshaft is provided with three cams for each valve, one centrally located with small lift height, 3.6 mm, and two equally sized outer cams with big lift height, 10.0 mm. With a small lift height at low load and at engine speeds up to approx. 3000 rpm, the primary benefit is lower fuel consumption.
In principle, during the time that the lift height is small, the air damper is completely open. Control of the incoming air volume to the cylinders takes place through control of the camshaft's opening times. Hereby the pump losses are reduced, which in turn gives lower fuel consumption. For more information, see Design and function, Engine control module (ECM).

Low lift
At small lift height (4), only the centrally placed cam acts on the valve, which takes place trough the inner valve depressor. The outer cams act on the outer valve depressors, which follow the cams' movement. Since the centrally located valve depressor and the outer depressor are not connected, the outer depressor moves without affecting the valve. Thus, lift height becomes small.

High lift
At high lift height (3), the inner valve depressor is connected with the outer valve depressor with lock pins. The outer camshaft cams' movement is transmitted through the outer valve depressor, on through the lock pins and the inner valve depressor to the valve. Thus, lift height becomes big.

The position of the lock pins is controlled hydraulically with two electro-hydraulic valves. One electro-hydraulic valve controls the valves for cylinders 1, 2 and 4, while the other controls the valve for cylinders 3, 5 and 6. Thus, the electro-hydraulic valves control 6 valves each (as the engine has 2 inlet valves and 2 exhaust valves per cylinder).
The position, on/off, of the electro-hydraulic valves is controlled by the Engine control module (ECM). For more information, see Design and function, Engine control module (ECM).

The inner valve depressor works like a hydraulic valve depressor, which compensates any wear. Thus, the valve clearance is "0".

The exhaust camshaft is conventional and has a lift height of 10.0 mm. The valve depressors are mechanical, that is, they "have" valve clearance.


VS Turbo Which does not have any switching of the valves.

It has been quite a few years, but I went into lots of SI6 engines and don't remember ever seeing extra lobes on the turbo cars.

 

[bobxyz]

Thanks Jordan! These "new" Volvo engines sure are complicated compared to the old redblocks, but they do have some fascinating technology to squeeze out more performance while still within the emissions and reliability requirements.

Either version of the SI6, NA or Turbo, sure seems like an admirable challenge to get working from scratch with an aftermarket ECU and no example tunes to start with.

 

[Meatball]

Thanks Jordan! These "new" Volvo engines sure are complicated compared to the old redblocks, but they do have some fascinating technology to squeeze out more performance while still within the emissions and reliability requirements.

Either version of the SI6, NA or Turbo, sure seems like an admirable challenge to get working from scratch with an aftermarket ECU and no example tunes to start with.

I actually got a timing light. I gave my old one away about two years ago with my white 245.

This is what I have done for most of the day. Well, this and messing around with the dashboard. Getting a place for power, making a mounting fixture for the Raspberry Pi, etc. This is V1 of my crankshaft nose adapter that I hope will fit under the seal for the front of the engine. There is a spot in the middle left during manufacturing that is only rubber. I presume it is there to assist with removal. You normally only ever remove the seal to fit the crankshaft tool for rotating the engine. That tool is part of the timing chain kit. Anyway, the next step will be to print it and sit it under the seal. Then find some way to add degree indicators to the seal face for references. I might wind up having to recreate the seal to add the timing marks. We will see.

It was more work than should be necessary, I'm sure. It is definitely a challenge to go down a road that barely even exists, lol.

Like I was telling my dad earlier, I'd like to have a word with Frost...

Two roads diverged in a yellow wood,
And sorry I could not travel both
And be one traveler, long I stood
And looked down one as far as I could
To where it bent in the undergrowth;

Then took the other, as just as fair,
And having perhaps the better claim,
Because it was grassy and wanted wear;
Though as for that the passing there
Had worn them really about the same,

And both that morning equally lay
In leaves no step had trodden black.
Oh, I kept the first for another day!
Yet knowing how way leads on to way,
I doubted if I should ever come back.

I shall be telling this with a sigh
Somewhere ages and ages hence:
Two roads diverged in a wood, and I -
I took the one less traveled by,
And that has made all the difference.

- Robert Frost

 

[Meatball]

SI6
Turbo
Intake PN 30750001
Exhaust PN 30750002

Non turbo (S and S5 engines)
Intake PN 30731249
exhaust PN 30731248

Non turbo (S2 and S4 engines)
intake PN 30759892
Exhaust PN 30731248

I absolutely would NOT trust the VIDA parts diagrams for any actual information. They will show generic or wrong photo's all of the time.

Thanks for doing the legwork on that.

Of course there is a lot of mixed up information. I can't even tell you the number of times that I, myself, have been on one screen looking at a wiring diagram and making notes only to realize that I have scrolled to the next page. Multiple times during this process, I have thought of the poor soul(s) responsible for maintaining the literature at Volvo Corporate.

Edit:// and I have also been lulled multiple times into trusting an image like the camshaft especially when it actually shows the cam trigger wheel corresponding to the physical attributes seem through the hole in the cylinder head, lol. I guess there is a lot of copy/paste and a healthy dose of "it's good enough". They probably never had a single thought about someone trying to do what I am doing right now

 

[GTJordan]

View attachment 35416

I actually got a timing light. I gave my old one away about two years ago with my white 245.

This is what I have done for most of the day. Well, this and messing around with the dashboard. Getting a place for power, making a mounting fixture for the Raspberry Pi, etc. This is V1 of my crankshaft nose adapter that I hope will fit under the seal for the front of the engine. There is a spot in the middle left during manufacturing that is only rubber. I presume it is there to assist with removal. You normally only ever remove the seal to fit the crankshaft tool for rotating the engine. That tool is part of the timing chain kit. Anyway, the next step will be to print it and sit it under the seal. Then find some way to add degree indicators to the seal face for references. I might wind up having to recreate the seal to add the timing marks. We will see.

It was more work than should be necessary, I'm sure. It is definitely a challenge to go down a road that barely even exists, lol.

Like I was telling my dad earlier, I'd like to have a work with Frost...

I'm sure you're already aware of this. When mechanically setting the base timing of the engine with the special tools, you are NOT setting things to TDC. The pistons will be down the bores. I couldn't tell you any accurate readings.

 

[Meatball]

I'm sure you're already aware of this. When mechanically setting the base timing of the engine with the special tools, you are NOT setting things to TDC. The pistons will be down the bores. I couldn't tell you any accurate readings.

I'm just using that special 1/2" adapter to rotate the engine by hand.