2001 V70XC No crank no power after stalling

[JunkYardAddict]

Thank you.

the OBD Scanner that I am using is an OBDII scanner that I purchased a few years back at Harbor Freight. It has worked fine for other cars that I had in the past.

I will follow your suggestion and try to read the CAN resistance at another point of the network instead of the OBD pins. I did check both fuses (actually all of them), and they were all found to be intact.

Below is the method for testing the CEM that I go from a Volvo Technical Bulletin. It tells to check the CAN-H and CAN-L at the OBD pins. Take a look and let me know what you think.

CANbus hardware and measurement
The CAN network system is set up with network resistors of 120 Ohms placed inside some nodes, and connected between the two CAN wires (Green(GN) for CAN low and White(W) for CAN high)
The two nodes in the low speed network (basically passenger compartment) that have the network resistors are REM and UEM. For the high speed network (basically engine compartment) it depends on engine type and model year. For MY99-MY01 the nodes that have the network resistor are ABS and ETM. From MY02 and later vehicles with Bosch EMS, the ETM is no longer on the high speed network.
Instead that end resistor is in the ECM.
Method
To identify a permanent fault condition in the CANbus it is possible to measure the CANbus resistance. The CANbus must be measured with the negative battery cable off and should be close to 60 Ohms. An open in one or both of the CAN wires will result in a reading of 120 Ohms. It is recommended to measure the resistance with the CEM breakout box connected. That gives the following advantages:
1. The networks will be tested including the CEM. Note however that open circuits in ABS/BCM, SAS, PSM, PDM, DDM and AUM will still not affect the 60 Ohm measurement since these nodes are not connected in series. A short between the green and white will however be detected.
2. You will have easy access to the low-speed network, high-speed network and the wires between CEM and the data link connector.
3. Having the multimeter in the footwell area, wiggle the cables/connectors in the bulkhead above the CEM and look for changes in Ohm reading.
4. As under 3. wiggle also the cables/splice behind radio where radio cables meet firewall harness.
5. As under 3. wiggle cables/connector at A pillar that connects the roof harness.
6. As under 3. have someone wiggle the cables under the coolbox for ECM and TCM.

[doublebug]

First about scanner. It should be able to:
1 read diagnostic codes via CAN.
2 Send special diagnostic commands via K-Line to connect OBD CAN to the car.
3 Be able to talk to Volvo.

If adapter uses K-Line only you will see only Engine codes.

I would buy DiCE clone since VIDA is not only scanner software but also maintenance and repair database. For almost every error code you have information about fault tracing.

About CAN testing. Breakout adapter just makes access to module pins easier. So when you use some thick needles to check in the sockets sometimes contact can become loose. Breakout box uses the same sockets as module does and provide additional contacts for all pins to check with multimeter.
The rest of information is useful.

Actually I don't think you have CAN issue. Symptoms will be different.

[JunkYardAddict]

Well, it is time for a quick update now that the temperatures are starting to warm up a little and I can go outside to work on this car.

Over the holidays I have purchased a VIDA-DiCE unit. As many have reported, the software disk came corrupted and was of no use. Fortunately there is the virtual machine for running VIDA-DiCE, and thanks to "precopster" for sending me the links and instructions.

After taking a while to figure out how to set up the virtual machine, it is up and running, and according to VIDA, the DiCE unit was checked and is OK. This is where the good news ends.

I was unable to read information from the vehicle. Attached is the error message that I have received, and before you ask me if the key was in the Pos II in the ignition, the answer is yes. I had tried this a couple of times, with the same outcome.

"Not possible to read out information from the vehicle - Possible causes: Ignition is off; Problems with CT or cables to vehicle; Problems with communication between CT and PC; Faults in the vehicle CAN; Non programmed or faulty ECU."


Open to ideas at this point.

[doublebug]

Do you hear any relay clicks while try to read vehicle?

[draser]

Going back to your first post - it seems the OBD port is disconnected from CEM, I'd check its wiring into CEM. If you've done that and checked okay, and have voltage and grounds at the CEM I'd focus on CEM wiring and perhaps bad module. I'd measure CAN at CEM.

[doublebug]

In these CEM modules OBD CAN is not connected directly. You need to send some special command via
K-Line interface to connect both buses. So sometimes when CEM is faulty it cannot do that.

[JunkYardAddict]

Now that the snow has melted and it is not so cold to be outside working in the car, I have gone back to check on the car, and you won't believe what I have found.... Everything is working again. I saw the red light on the dash blinking when I went back to the car. Tried to start, and it started.

I am still suspicious of this car, so I am not planning on taking any trips with it until I figure out what was wrong in the first place. The one thing that is still there is the warning message on the dashboard saying that SRS (Air bag) has failed.

My suspicion is still with the CEM since there was no power to anything other then the components that receive power directly from the battery. Everything that is not powered directly from the battery (e.g. radio) has to go through the CEM. I haven't removed it from the car yet (not so easy to get to), but it could have water damage that subsided while the car sat out there all these months.

I still can't believe that this thing came to life. Also don't trust it until I know what caused it to not function in the first place.

[JunkYardAddict]

So, now that the temperatures have warmed up a little, and my "honey do list" is a bit smaller, there was some time left to hook up the VIDA-DICE unit to the car and see what it would tell me. Well, it didn't tell me much, at least not anything too obvious.

A couple of days ago, twice in the same day, the hazard lights were blinking (nobody touched the car), so I unlocked the car, put the key in the ignition - red LED on the dash was blinking very fast - and started the car (no problems so far) and then turned it off, and locked the car.

One of the codes from VIDA was UEM-0004 - Siren Communication Fault. I had seen this before in the forum, and read most of the posts about it. I have also tried the troubleshooting instructions from VIDA-DICE and confirmed that the siren is not working. The random blinking of the hazard lights (flashers) seems to indicate that there is something wrong with the unit and possibly corrosion from a leaky internal battery is causing this thing to malfunction.

So, here is the question: If the siren module is malfunctioning, could it have caused the complete shut down of my car and the absence of power on everything that didn't receive power directly from the battery (perhaps by affecting the immobilizer)?

[JunkYardAddict]

Replaced siren module with the help of a "donor" unit from the junk yard (had a good board in it) and a battery pack purchased on-line (NiMH, 7.2V, 400 mAH). Tested with Vida-DICE, and it works. Many thanks to "precopster" for directing me toward getting Vida-DICE to properly diagnose this problem. Still can't believe that a little rechargeable battery inside the siren module could cause so much trouble (stall in the middle of the highway and being towed home twice).