Posting also in general forum as this has likely been seen on many models.

2011 XC60

3rd time it's happened, this time wont restart??? Brake Failure Stop Safely message on with just about every dash light (parking brake, traction control, CEL, etc.) Scan for codes and none are returned... Any advise?

Also, gear shifter wont move from park?

Battery?
BCM?
Some Sensor?

Thx

 

BCM? I'd suspect if there was a sensor at fault, it should throw a DTC. Battery / system voltage is a possible cause and worth some testing, but again a low voltage scenario will most often throw DTCs (even if they are "false positives"). What is remaining is a wiring or circuit board issue that causes a loss of communications between components. Not all scanners can see the proprietary codes so your next step is to go to a shop equipped with a VIDA DICE (dealer or a shop that does a lot of Volvos).

As to the shifter, that sounds like the brake interlock is not sensing the pedal as being depressed so that may suggest a problem with the pedal position sensor or the communications path between the ABS computer and the transmission computer etc.

 

Good Suggestions, thx for replying so quick. I'll work on heading down those avenues to see if any are the culprit. A little more to report, I went to my wife's work to see if id be able to get it moving again to get it home. No such luck unfortunately... While I was there, I attempted to scan for codes again, only this time the scanner was unable to communicate with the ECM. Disconnected the battery in hopes of resetting the system if there was a glitch. Swapped batteries with a known good one. Checked fuses. Still no luck... This time it seemed it would not recognize the shifter being put back in park which also may be leading to these issues.

The first two times this happened (both in the past 10 days), she was able to pull over, turn car off and once restarted, everything was back to normal.

So I'll check the pedal position sensor first. Then I guess get into the BCM and/or possible wiring issues

Thx again mt6127

 

Update...

Looks like the car is going into an immobilization mode (for some reason). Left car at my wife's work over the weekend, started up fine this morning. I drove home (about an hour), got with in 3mi of home and same thing happened. Shut down, "Brake Failure - Stop Safely" message accompanied by a bunch of lights (i.e. traction control, blinking park brake, etc. etc.), go to restart and nothing. Immobilized messages flashes when attempting to restart. Towed her home and been running through the check list of possible issues...

*All CEM wiring connection are tight (along with every other connection I could get my hands on around the engine compartment and under the dash)
*Battery has good charge
*New batteries in key fob

Went to replace the brake pedal position (pressure) sensor, only to find out that this car has the brake booster which does not have the sensor (apparently there are two types). Couple of sensors on the pedal itself, but unsure if either may be the culprit or what they even are exactly?

I guess could still be bad BCM or ECM???

What else could be throwing it into immobilization mode? Especially while driving? Or does it sound like it may be unrelated issues. Seems to be occurring far more often in the last day or two. I suspect when I get out to the garage and reconnect the battery everything will work as normal now that the system has had over 5 hours to reset the immobilizer.

Any additional thoughts???

Thx again!

 

when you say "immobilizer" do you mean "limp mode"? Sounds like your car is going into limp mode when you throw a set of safety related fault codes. The immobilizer is the anti-theft system. Its supposed to allow a reset by locking/unlocking the doors 5x with the key or fob.

 

No, not Limp Mode, car doesn't start or run. The message on screen when trying to start shows Immobilized - Try Starting Again

Just went out and hooked the battery back up and no change, still shows Brake Failure and every several dash lights on. No start...

 

More to report...

Finally was able to get my scanner (Autel 906) to communicate with onboard diagnostics system. Had 49 faults, 23 in CEM, just about all were tied to loss of communication or low voltage. Given that, I went ahead and replaced the battery with new. Car starts right up on every attempt now, but messages/lights/codes immediate flash on dash???

Should I be leaning towards a bad CEM at this point?

How about a faulty BCM or DEM?
Anything else to check?

 

did you record and clear all the codes to see if they reset? I'd also monitor system voltage. newer cars monitor power demand so the alternator doesn't always run full out - wondering if your voltage drops below 12.6V from time to time resetting codes. This would point to a wire harness or alternator issue.

 

I have cleared codes (after saving a PDF of DTC's), some would not clear at all and many came back upon first start attempt. Now not starting again. I can hear the starter spin on 3-4 attempts until the immobilizer kick in, then nothing just a bunch of messages and lights. I think I've narrowed it to an electrical short in one of the modules (not sure if CEM, ECU or DEM), is there any way to test/check to determine which before pulling and sending for a rebuild???

Pulled all connections off both the CEM and ECU, cleaned with contact cleaner, inspected and ensured snug fitment. Double checked power cable to starter is tight, all connections around battery terminals are tight with no signs of compromised wiring. Still getting an issue with the gear shifter getting stuck either in P or in N if I get it moved. Once back firmly in P, there's a message indicating it still needs to be shifted to P. Could this all simply be a shift position sensor? Is there a brake pedal position sensor located somewhere else (not on the brake booster in the model I have, appears there ae two booster models???)

Just trying to eliminate anything possible prior to pulling either the CEM or ECU.

Again, greatly appreciate the replies!

 

Attached: Scan Results

 

Thought I had it solved, but back to where I started. Changed the accelerator pedal since that was one of the only specific "low signal" faults I was getting (all other faults were communication loss between BUS or inconsistent voltage issues). After pedal was installed, started right up with no faults or lights on, ran as normal. On road test, got about 1mi in and same faults began to occur, lost engine power and coasted to a stop. Now unable to shut down power to car with the start/stop button. Had to unhook battery. Definitely sounds like a network communication fault somewhere...

Should I jump to CEM?
Could a failing start/stop button cause this?
Should I be looking elsewhere?

Thx

 

Started working on issue again after being away for several days, car started right up without issue, no faults or warning lights. Monitored charging system and reports "high voltage check system". Voltage output around 14.78v, could high voltage contribute to the issue I'm having

 

Yep, that'll do it. Too much or tool little volts can cause false diagnostic codes. Sounds like you need to replace the voltage regulator - google Volvo #30667685. You should be able to replace just the regulator not the whole alternator. I bet if you monitored voltage you'd find it will wander from 12 up to 15+ then back... Some of the big box stores will also test the alternator for you just to be sure.

 

Update:
Last night I replaced the accelerator pedal again (to rule out) and replaced the voltage regulator. Upon initial start, got "power steering service required" message, but everything else seemed okay. Performed alternator test, came back with and acceptable 13.77v. Took for a road test this morning, same power steering message on start up, had no power steering. Shut off and restarted, same message again, but this time power steering was back??? Completed road test and performed another alternator test. This time came back with same "high voltage check system" report with voltage 14.98v. During test, voltage ranged between 14.18-15.03. What should I think now, bad alternator??? I'd think the new voltage regulator would compensate for an over performing alternator??? And why the power steering message now???

This car, ugh

 

Now have all the original faults/error messages as I originally did...
Check Engine
ABS
DSTC
Park Brake (blinking)
Brake
Red Triangle w/ exclamation mark

DSTC Service Required
Coolant System Required
Park Brake Service Required
Park Assist System Service Required
Power Steering Service Required
Brake Failure Stop Safely

Should I now be leaning toward the CEM???
If so, why after the car sits for a few days, it starts up fine with no codes then after about 10min of running, all come back?

Or could this be all tied to the high voltage output???

 

not sure how the CEM would be tied to the voltage output but I've not looked at a wiring diagram. I'm wondering if there's a cabling issue to the battery or ground where there's too much resistance causing the sensing circuit to think the alternator's output is too low. Not sure where/how to check but that's where I'd research next.

 

I'll go ahead and check resistance on all cables.

I guess what I was thinking about the CEM and high voltage output, was would elevated voltage start creating havoc with the CEM function?

 

Received CEM back from cloning service. Installed and fired car up with fingers crossed... NO LUCK

Still have no power steering and DTC's:
*Loss of Comm w/ TCM
*Internal Control Module Software Incompatibility
*Control Module Comm Bus "A" Off
*High Speed CAN Comm Bus

?????

 

Hi, I'm having some issues same as your car. I removed CEM and all connectors terminals good not rust. But didn't try anything else. Most people on other forms point to the CEM.
Did you get luck fixing yours? Please update,thanks.

 

Hello, I have a S60 2011 T6 and have the same intermittent issues as you related!


I run around all Internet searching information, as the dealers never found a clue of what is going on, and through tests, I was eliminating possibles roots to the problem:

- car has new battery
- car has new alternator

But the most important info of all its:

THE CAR JUST GET THE ISSUES IN HOT WHEATER!

Its like plug and play -> The car sits directly on sun for couple minutes and all the codes become to pop up and I can’t start the car. But when the sunset occurs and the car cools down, everything come back to the normal.

I made a few tests:

Leaving just the HOOD in the sun -> the car runs perfectly.

Leaving all the car in the sun with sunshades in the front window -> the problem takes more time to come, but appers.

So, the problem its related to the high temperatures insides de cabin. This conclusion took me to the forums about this kind of issue in the P2 plattaforms cars.

In that case, most of them solved the problem after pointing to CEM. The CEM get warmed by the inside temperature and go crazy, throwing all the erros.

With that in mind, I made more tests:

- Sits the car in the sun to recreat the problem
- Few minutes later, Errors come up: lights on, but no start
- Take a regular home fan and pointed direct under the glovebox (where the modules like CEM are installed)

AND BAMN!

- 2 minutes later the car started!

So, I guess that I am getting close to the root of the problem.

My next steps are: checking the internal board of the CEM, maybe get cold solder / bad solder and install fans under the glovebox to circulate that air and let the CEM breath freely!

And your problem, was solved? Any updates