Corrupt Canbus, xemodex said good luck

[imac]

I'm not sure if it's at all related but the fuel gauge doesn't work 100%, the car is out of fuel at 1/4 left on the gauge, it suddenly goes for 1/4 to 0 and the car dies pretty much. Also the clock doesn't count up or down, I can set it to 1pm and it will remain at 1pm indefinitely.

[jimmy57]

I don't like the 4th panel. The others look good for what is in or out of CAN. The waveform should be a mirror image that looks identical 1.5 V up compared to 1.5 V down. The amplitude varies a little as the different modules that create the signal during their broadcast period have max and min values. The 4th shows the 1.5V center is messed up with ABS is circuit. The modules will not always be in failure 100% so the times when CAN is OK with ABS connected doesn't surprise me. The CEM is there 100% of the time and it is on the suspect list as well as ABS. As Yagger says, CEM could be it in spite of a clean report from XEMODEX. I don't know which is cheaper for you: send ABS to be checked by XEMODEX or get a dismantler ABS module for testing. The same exact part number ABS module should be a plug n play for that car.

[imac]

To eliminate the ABS module, I'll disconnect the battery, disconnect the abs module, reconnect the battery and go for a drive!

What you're saying about the 4th wave makes sense.

Again, thank you for the replies

[yagger]

Ok. We offer online service for Volvo. We can find your issue 100%. Big point for you - you have oscilloscope and you know how to use it, it's means we can find your issue faster.
You say "the clock doesn't count up or down", this point show me there is issue in your CEM.
I can offer for you 3 options:
1. you can buy CEM with number I will give you, send to us for full clone.
2. you can buy CEM with number I will give you, we can do transferring of data from your original CEM to used CEM online (but, there is one small point, for most people it is not important point, about it to PM please).
3. we can read your CEM online, and do full clone of your CEM to ours one and send it to you (but we send to US address only, if you have it...).

[imac]

I'm interested in more info I'll send a PM.

In the meantime I disconnected the battery ground and shorted it to + and let it sit for half hour, unplugged ABS and reconnected the battery. The BRAKE FAIL message appeared right away, with the ABS unplugged.

[jimmy57]

The brake fail message will appear when it is off line. The CEM will turn that message on if there is no comm with ABS.

[imac]

Haha, yes that makes sense, I'm so used to BRAKE FAIL meaning my volvo is going to run shift and drive like crap, not that BRAKE FAIL would have anything to actually do with the brakes...

I ran the car a few times with the ABS unplugged. The gauges all worked for a bit, then didn't. Restart typical with chattering brake solenoid at the shift column, revs pick up, misfire. I feel it overall ran better though? Maybe it's just in my head, wishful thinking.

I'm wondering if I have 2 failed modules, like ABS & ETM. I'll leave the abs unhooked for a while, see what happens.

With the abs unplugged I ran a vida scan, this is what wouldn't clear:

Dec 5.jpg (43.6 KiB) Viewed 140 times

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The ECM-902A Throttle error is making me wonder about the ETM.

[imac]

I received an email back from xemodex this morning:

I can certainly understand why you were suspecting the CEM. Issues on both the high speed and low speed. The clock issue is a little worrying. That would usually indicate a CEM problem, but I'm surprised we didn't see anything wrong with it. How often does this issue occur?

All the time, constantly and consistently

It's possible there is more than one issue going on here. So you may want to try addressing the obvious. The SRS internal fault code sticks out for the low speed network.

On the high speed network, I would lean slightly toward an ECM, but the clock thing still isn't addressed … so maybe before anything is done that's too expensive, see about getting a software update. There's a pending software upgrade available for this vehicle, as well as a TCM upgrade. See if those yield any results.

The software upgrade should be done for free under Volvo service 2.0 at any Volvo dealership. It used to be completely free, but they've recently changed the wording to "free with any service", so they may make you do something. An oil change or even just an inspection will likely be fine.

I booked an appointment at the volvo dealership for Dec 17th to update software. They cannot confirm or deny over the phone if any software is available for my car, until they plug into her. Minimum 1h shop rate @$155

While driving today with the ABS unplugged, upon a restart the DIM displayed NO OIL PRESSURE which I have NEVER seen before. Of course I checked the dipstick and it's right on full, so what that's about I'm not sure.

I'm going to try to find a parts car, or spare cem at least in the meantime, and hopefully the software update will return some results at the dealer. Here's hoping, anyways

[yagger]

Also, you have to remember, if you have a problems with CAN from CEM, dealer can kill your original CEM when they start to upload software. Just you should know about it.

[abscate]

Also, you have to remember, if you have a problems with CAN from CEM, dealer can kill your original CEM when they start to upload software. Just you should know about it.