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Error messages abound, parking brake stuck, and a 5000 lawn ornament. HELP!
- Thread starter geordi
- Start date
Happy to try this first, where is the parking brake control module?
I think I probably still have to take the wheels off to unwind the motors anyway, i’m going to unplug them and hopefully that clears things but maybe this is coming from the module…. For reasons I don’t know.
The last time I powered it up I did have a tire warning but I also have a suspension warning on the dash, possibly just because everything had been powered off and it hasn’t driven to reset. it still has the old Baofeng (or whatever) TPMS system.
There are no parking sensors on this vehicle. This is a 2013 with no AP hardware stuff.
Parking brake module is in the trunk area behind the passenger side wheel well. The service manual has the details and pinout.
Motors are 12V so you can theoretically back them off from the module connector with a couple jumper wires (don't damage pins).
Make sure that you know which pin you try to connect this 12V as the connector has four of them. Two for the motor (+/-) and two for the inner sensor. You will definitely damage that sensor if you will use the wrong pins.
Indeed, EPB control module has 2 connectors and the motors are different pins on each one.
To avoid that potential (and because I don't have any test leads around at the moment) I skipped that problem by just unscrewing the planetary gearbox from the caliper and pulling the motor and gearbox entirely. Both wheels are now free rolling.
It has exactly the same list of errors when powered up.... Still no gearshift. So I'm wondering if maybe the module is the cause. Looking it up right now b/c there are two stacked modules, one is labeled as the power liftgate (so that's unlikely to be the one, duh) but I want to confirm that the other IS the brake module and which plug is the one to pull for the CAN bus connection.
Yup - connected HV first, then LV. Disconnect was the reverse. MCU took forever to come up, dash computer came up way quicker.
You can pull both connectors from the EPB. As Ibread it, CAN is on the 20 pin connector and power is on the 10 pin.
Well there’s a partial result!
Unplugging the parking brake module, when I boot everything back up the dash comes up but the MCU does not. It is sitting in car off mode. If I leave it alone for two or three minutes, it seems to satisfy itself and I can actually get it to go into gear. Still in service mode with tons of errors.
The first time I got it to move, as soon as the MCU started booting up the dash went black and refused to come back. That seems to have been cured by waiting two or three minutes after connecting the battery, then everything stays on while it allows you to shift into gear.
Since it cannot detect the parking brake it refuses to go into park mode, that’s understandable. What is not understandable, is that I can watch the computer freak out and lose connection to everything that it could not talk to before, and then at some point it will come back, and then a few seconds later go away again. The cruise control stalk will stay lit up and the turn signals will work intermittently. If it shows the active error that it cannot talk to the shifter, it will not shift and the horn will not work. Then the situation resolves itself and it will on both.
This seems like a communication failure on the bus. But I definitely have not got the first clue of where to look.
Here’s a video of what I’m seeing on the screen, with this thing detecting and then clearing the alerts over and over. While it was driving, it did seem like the power steering was working fine so you can see that error pop-up which proves that everything here is intermittent. Same for shifting to reverse or drive, and then it can’t communicate with the shifter again.
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Unplugging the parking brake module, when I boot everything back up the dash comes up but the MCU does not. It is sitting in car off mode. If I leave it alone for two or three minutes, it seems to satisfy itself and I can actually get it to go into gear. Still in service mode with tons of errors.
The first time I got it to move, as soon as the MCU started booting up the dash went black and refused to come back. That seems to have been cured by waiting two or three minutes after connecting the battery, then everything stays on while it allows you to shift into gear.
Since it cannot detect the parking brake it refuses to go into park mode, that’s understandable. What is not understandable, is that I can watch the computer freak out and lose connection to everything that it could not talk to before, and then at some point it will come back, and then a few seconds later go away again. The cruise control stalk will stay lit up and the turn signals will work intermittently. If it shows the active error that it cannot talk to the shifter, it will not shift and the horn will not work. Then the situation resolves itself and it will on both.
This seems like a communication failure on the bus. But I definitely have not got the first clue of where to look.
Here’s a video of what I’m seeing on the screen, with this thing detecting and then clearing the alerts over and over. While it was driving, it did seem like the power steering was working fine so you can see that error pop-up which proves that everything here is intermittent. Same for shifting to reverse or drive, and then it can’t communicate with the shifter again.
2023-03-10 17-40-56.mov - Shared with pCloud
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Last edited:
That is weird. Could be the gateway, could be a module on the bus.Well there’s a partial result!
Unplugging the parking brake module, when I boot everything back up the dash comes up but the MCU does not. It is sitting in car off mode. If I leave it alone for two or three minutes, it seems to satisfy itself and I can actually get it to go into gear. Still in service mode with tons of errors.
The first time I got it to move, as soon as the MCU started booting up the dash went black and refused to come back. That seems to have been cured by waiting two or three minutes after connecting the battery, then everything stays on while it allows you to shift into gear.
Since it cannot detect the parking brake it refuses to go into park mode, that’s understandable. What is not understandable, is that I can watch the computer freak out and lose connection to everything that it could not talk to before, and then at some point it will come back, and then a few seconds later go away again. The cruise control stalk will stay lit up and the turn signals will work intermittently. If it shows the active error that it cannot talk to the shifter, it will not shift and the horn will not work. Then the situation resolves itself and it will on both.
This seems like a communication failure on the bus. But I definitely have not got the first clue of where to look.
Here’s a video of what I’m seeing on the screen, with this thing detecting and then clearing the alerts over and over. While it was driving, it did seem like the power steering was working fine so you can see that error pop-up which proves that everything here is intermittent. Same for shifting to reverse or drive, and then it can’t communicate with the shifter again.
2023-03-10 17-40-56.mov - Shared with pCloud
Store videos in pCloud. Share them with just the right people. Access them on any device. Create a free account now!
You might try isolating the majority of CAN C by removing pin 2 from X741 and X742.
Pulling pins before probably bringing to service seems like a bad idea.....
One other discovery - since I unplugged the parking brake module, the rear hatch refuses to work - it just beeps 3 times angrily at me when either button is pressed, but I didn't see an error for that module in the list. - interestingly I just remembered that it also beeps when the fob is used. Maybe it IS still on the CAN bus then.
I do find it curious that ALL the recurring module errors and the parking brake (which might be the module or it might not) all happened at the same time.
The first incident was a week ago (ish) and the following all popped alerts on the dash screen for my sister:
Parking brake, ESP, ABS, steering assist, airbag - this may not be the full list as it was 5:30 AM and my sister was somewhat distracted by not being able to get to work. The car DID still drive at that point. When it finally timed out from not being willing to shift to park (either the parking module OR the shifter maybe not communicating at that point) it DID set the parking brake which was where I found it.
So at that point on first wake up (batteries connected the whole time though), the brake module wouldn't communicate to release.... Which seems to suggest that the EPB module is the fault. If disconnecting that also cut off the rear hatch from the CAN bus, that might suggest that the EPB wasn't the terminator, BUT now there's a gap in the bus if they are all wired in series?
If it is the EPB module though.... How does a module just "go bad" like that? There's no source of voltage spikes, everything else is still connected.... SO CONFUSED.
One other discovery - since I unplugged the parking brake module, the rear hatch refuses to work - it just beeps 3 times angrily at me when either button is pressed, but I didn't see an error for that module in the list. - interestingly I just remembered that it also beeps when the fob is used. Maybe it IS still on the CAN bus then.
I do find it curious that ALL the recurring module errors and the parking brake (which might be the module or it might not) all happened at the same time.
The first incident was a week ago (ish) and the following all popped alerts on the dash screen for my sister:
Parking brake, ESP, ABS, steering assist, airbag - this may not be the full list as it was 5:30 AM and my sister was somewhat distracted by not being able to get to work. The car DID still drive at that point. When it finally timed out from not being willing to shift to park (either the parking module OR the shifter maybe not communicating at that point) it DID set the parking brake which was where I found it.
So at that point on first wake up (batteries connected the whole time though), the brake module wouldn't communicate to release.... Which seems to suggest that the EPB module is the fault. If disconnecting that also cut off the rear hatch from the CAN bus, that might suggest that the EPB wasn't the terminator, BUT now there's a gap in the bus if they are all wired in series?
If it is the EPB module though.... How does a module just "go bad" like that? There's no source of voltage spikes, everything else is still connected.... SO CONFUSED.
The hatch module is the one next to the EPB module. If EPB was the terminator, that might impact the hatch especially. EPB is not a pass through though.
Hatch could be complaining because it doesn't know the park state. Could try unplugging it and reconnecting the EPB.
EPB could be bad, or just reacting to a failed CAN in it's own way. You could also try disconnecting the power connector for EPB and leave the second connector with CAN connected.
X741/2 are shorting jumpers for CAN, it's a way to isolate bus sections, but might require tools to separate. You'd mentioned being wary regarding SvC diagnostics, so I figured I'd mention it. The less intrusive way would be pulling module fuses to (theoretically) stop them talking on the bus.
I appreciate the help - if you are familiar with my experience with Tesla Corporate.... You know why I'm less than eager to deal with the service centers. I'm the guy that they tried to ransom 30% of my battery range for $4500. That and the other several experiences I have had (all WAY more expensive than originally quoted, lied to in obvious ways, general lack of communication and incompetence on process....
But this SC in CT seems halfway competent at least at the moment. I'm hoping their remote diagnostics can at least discover SOMETHING, I got confirmation that they hadn't even tried anything yet, so I'm going to be powering it back up with the brake motors (electrically) connected and all the modules online, and let them have their shuffle at it. At least with the motors loose from the calipers, I can move it if needed.
But this SC in CT seems halfway competent at least at the moment. I'm hoping their remote diagnostics can at least discover SOMETHING, I got confirmation that they hadn't even tried anything yet, so I'm going to be powering it back up with the brake motors (electrically) connected and all the modules online, and let them have their shuffle at it. At least with the motors loose from the calipers, I can move it if needed.
You mentioned brake motors electrically connected. I'd also put them back on the rotor, not sure if they can handle operation without something to clamp against.
NewbyMaybe
Newby1Kenowby
EG is “nearby” by around a 3-5 hour drive or so, they are just north of Boston and I’m west of Hartford. So not exactly next door.
Meanwhile, I powered the car back up and had to do that first in order to set the suspension and get the wheels off. It came back up with most of the errors but allowed me to move it without excessive complaining and the intermittent bus problems seem to be gone. I’m scratching my head. There doesn’t seem to be any root cause!
I connected the brake motors back up, and as expected they spun just fine. The computer is not happy with them because they are not attached and it was still complaining that there is a parking brake fault (brake may not be applied) but I think the error might be related to the run time of the motors. BOTH spin.
While I was moving it around I got errors again about steering assist being reduced and I currently have active errors about the stability control, traction control, ABS all being disabled.
But otherwise, it lets me shift just fine in and out of gear as many times as I want and everything on the steering wheel seems to be working perfectly. It’s like the CAN bus errors never happened.
Aaaaarrrrrggggghhhhhhh.
Since I now know that there is a sensor inside the parking brake motors as part of the plug, I’m wondering if that sensor has failed in one of them and that’s the cause of everything. Unfortunately, I won’t know the answer to that until I actually replace the motors.
I am willing to accept the possibility that the computer is upset about the parking brake and has disabled everything else related to brakes or traction control in the whole car, which seems a little bit like chopping your head off because your nose itches.
Meanwhile, I powered the car back up and had to do that first in order to set the suspension and get the wheels off. It came back up with most of the errors but allowed me to move it without excessive complaining and the intermittent bus problems seem to be gone. I’m scratching my head. There doesn’t seem to be any root cause!
I connected the brake motors back up, and as expected they spun just fine. The computer is not happy with them because they are not attached and it was still complaining that there is a parking brake fault (brake may not be applied) but I think the error might be related to the run time of the motors. BOTH spin.
While I was moving it around I got errors again about steering assist being reduced and I currently have active errors about the stability control, traction control, ABS all being disabled.
But otherwise, it lets me shift just fine in and out of gear as many times as I want and everything on the steering wheel seems to be working perfectly. It’s like the CAN bus errors never happened.
Aaaaarrrrrggggghhhhhhh.
Since I now know that there is a sensor inside the parking brake motors as part of the plug, I’m wondering if that sensor has failed in one of them and that’s the cause of everything. Unfortunately, I won’t know the answer to that until I actually replace the motors.
I am willing to accept the possibility that the computer is upset about the parking brake and has disabled everything else related to brakes or traction control in the whole car, which seems a little bit like chopping your head off because your nose itches.
The list of errors (and lost of horn) would not be due to an issue with a parking brake motor.
May be a wire harness issue.
Agree… BUT it popped up simultaneously with the parking brake issue, and nothing else on the car has been replaced other than the 12v battery - which changed nothing.
This is why I’m so stressed. I can’t leave this car with my sister, because she can’t trust it and I don’t blame her for that. It just fell over without any warning and now is back equally fast. So maybe tomorrow it will be broken again or maybe not…. That’s not reliable.
This is why I’m so stressed. I can’t leave this car with my sister, because she can’t trust it and I don’t blame her for that. It just fell over without any warning and now is back equally fast. So maybe tomorrow it will be broken again or maybe not…. That’s not reliable.
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