Volvo EC290B engine speed sensor problem

[alex111]

I have an 2006 EC290B (serial 12585), around 6000h on engine.
This machine was running fine, until it one day it became very hard to start. The starter was turning over with no problem, but engine would not catch on. I eventually got it started, and the engine was now running a bit unevenly, and the console was beeping and throwing this error: "128 SID 22 2". I looked this up and found it means that ECU is getting bad data from one of the engine speed sensors.

The machine has two engine speed sensors. I started by replacing the one on the rear of engine (that is easy to get to). This made no difference, so I replaced the one on the front, that is mounted right behind the flywheel. Both the new sensors are brand new, so I presume working fine.

Now the machine starts up fine on the first attempt (as it used to). No error messages on console right away. However when I rev up the engine (just 1 click on the dial is enough) the console will beep and throw this error: "128 SID 22 3" (note, same as before except last digit is a 2 instead of a 3). This error means that the machine is not getting any data from one of the engine speed sensors at all. I can operate the machine like this, and the error will come and go, and that is usually associated with a misfire, and the machine can lose a little power momentarily.

If I unplug the front-side sensor, the machine will start but throw the "128 SID 22 3" error immediately, even on the lowest RPM setting. So I am sure that the machine is getting _something_ from the new front-side sensor, and not nothing, as the error code suggests.

I'd love to get this issue fixed. Anyone have an idea what might be wrong here? What other component(s) should I consider replacing, if any? Thanks!

 

[uffex]

Good day
Sorry for the delay my buddy must be on holiday see attached, check the space between the teeth and sensor, wind it in till it touch's then back one turn.
Kind regards
Uffex

 

[alex111]

Hi Uffex, thank you for your reply.
I have to admit I don't know what you mean by winding it, are you saying the sensor is built such that I can twist it to make the tip of it come closer to the flywheel teeth? If so fantastic, will be an easy fix!

 

[uffex]

Good day
If you have a fixed version remove the sensor clean the face and gear wheel, the sensor will need to be within a 1/8th of an inch from the gears.
Kind regards
Uffex

 

[alex111]

Good day, I suspect mine is fixed, although I am not totally sure about that. I haven't had time to get back on this machine yet unfortunately but hope to do that today.
I understand I should make sure all the surfaces are clean - but that won't change the air gap of course, so I presume that if my sensor is not adjustable itself, then do you think the mounting bracket that holds it should be possible to adjust instead?

 

[funwithfuel]

Good day
If you have a fixed version remove the sensor clean the face and gear wheel, the sensor will need to be within a 1/8th of an inch from the gears.
Kind regards
Uffex
View attachment 295954

That's the crank sensor there. The one by the flywheel side going into the block is the cam sensor. There was a very few models where the cam follower would break and wad up in the engine, sometimes blowing out a chunk of the block. Check your pushrod travel.

 

[alex111]

That's the crank sensor there. The one by the flywheel side going into the block is the cam sensor. There was a very few models where the cam follower would break and wad up in the engine, sometimes blowing out a chunk of the block. Check your pushrod travel.

First of all let me say I was wrong in my initial post: the sensor that is hard to get to is not the one by the flywheel. It is still the one that is quite hard to get to on the front of the D7D engine though.

Now, you say the sensor that is by the flywheel (on the back of the engine, easy to get to) is the cam sensor. This is not my understanding, because all the sellers refer to this one as the "flywheel sensor" or "crankshaft sensor" (VOE20482772). For this engine, this one has a short cable (about 1 ft).

The other one the sellers label "camshaft sensor" (VOE22435058) and this one has a longer cable because it is mounted on the front of the engine (hard to get to).
128 SID 22 is supposed to indicate a problem with the flywheel/crankshaft sensor. So if that is accurate my problem would be with the easy-to-get-to sensor on the back of the engine.

I see no way to affect how close this one gets to the flywheel, because it goes into the engine, as you wrote above. I don't know how you could measure the air gap it ends up with.
But either way, when the problem first started, the flywheel sensor was what I first replaced, and that had no impact on the issue at all.

 

[funwithfuel]

Those sensors are fixed depth, you can only shim out away. Look at this easy. What is the front sensor monitoring? The tone ring on the crank. The cam shaft sensor is at the rear of the engine, fuel side, going right into the block ahead of the flywheel housing. The conne tors should also be labeled SE22XX or SE21XX indicating which sensor they in fact are.

 

[alex111]

Those sensors are fixed depth, you can only shim out away. Look at this easy. What is the front sensor monitoring? The tone ring on the crank. The cam shaft sensor is at the rear of the engine, fuel side, going right into the block ahead of the flywheel housing. The conne tors should also be labeled SE22XX or SE21XX indicating which sensor they in fact are.

Makes sense to me. I am very much a novice mechanic, and appreciate the explanation.

I will look for those labels.

What do you make of the "128 SID 22 3" error code that happens even after a new sensor has been put in? Do you have any suspicions on what else might be wrong, that would trigger that code?

 

[funwithfuel]

As mentioned previously, check your block around #s 5&6. The high pressure fuel pumps ride off the cam in the rear of the engine. If the cam or follower are shedding material, you'll have erratic cam signal which will not correlate with the crank signal. The computer throws a fit and logs the error. The other possibility is shorted wiring up near the main connector from engine harness to machine harness. Simple enough to disconnect and measure harness for opens, shorts, crossbleeds etc. I will try to find proper schematic.

 

[funwithfuel]

Please see attached

 

[alex111]

As mentioned previously, check your block around #s 5&6. The high pressure fuel pumps ride off the cam in the rear of the engine. If the cam or follower are shedding material, you'll have erratic cam signal which will not correlate with the crank signal.

This sounds like a pretty major operation, and probably beyond my capabilities, especially if the camshaft or the follower actually are shedding - this would mean the whole engine has to be stripped down, cleaned and rebuilt, no?

The electric stuff I should be able to measure / debug. I would need the testing harness and an OBDII breakout box, correct?

Could you advise if this is the correct testing harness?

https://www.aliexpress.us/item/3256805278185575.html

 

[funwithfuel]

With common sense and caution, you could perform the measuring at either CO01 or EA connector of E-ECU. You don't need to spend a fortune on specialized test equipment.

 

[funwithfuel]

That harness you reference doesn't have the actual box for pinning, so you'd need that as well. More expenses. Take a paper clip, hammer out the straight end til it's almost paper thin, Voila, you now have probing terminals. It's all about patience and practice. Take your time and don't force anything. You'll do fine.

 

[alex111]

With common sense and caution, you could perform the measuring at either CO01 or EA connector of E-ECU. You don't need to spend a fortune on specialized test equipment.

I am just worried that I would connect the wrong poles together and mess something up - or measure the wrong thing -> bad conclusion.

CO01.1 and EA30 (going from the diagram you attached above), can you deduce exactly which pins / pinholes in the connectors / ports those identifiers correspond to?

 

[funwithfuel]

I think we can hook you up with some good maps and diagrams. Just gotta be patient. There's only 4 or 5 of us, the Cat guys outnumber us. When I get back in front of a computer we'll see what we can provide

 

[alex111]

That would be great, I'll take anything you want to send me. Thank you!

 

[funwithfuel]

Lets take a look at the attached. I blew up the connector image so that cavity identification was easier. I suggest printing out the connectors and highlight the cavities concerned. That way you'll have the information at your fingertips.

 

[funwithfuel]

While you're in there, follow the passive measuring chart, it may uncover something. If you get comfortable with back probing , you can perform active testing as well. BTW, you can unbolt the ECU from the wall for easier acccess

 

[alex111]

Thank you very much funwithfuel. Look forward to working on this this weekend.

I understand the difference between active and passive testing. What I don't understand right now is how - without the testing wire harness and breakout box - you can do the testing on specific pins. Isn't the wire harness there to let you patch into the system while the system is still fully connected?
How do you do that without the harness?

Perhaps this becomes obvious to me when I work on it.