VDIM broken!!!
#1
11 Second Club
Thread Starter
VDIM broken!!!
Hey guys, I wanted to know your opinions... I have switched from my winter tires to summer tires back in April. I didn't put the TPMS in. For 4 months, it worked just fine - just the light was on the whole time for the TPMS. One day, the traction light is on with a CEL. I had no VDIM!!! I went to the dealer and the service guy simply told me that not having the TPMS made my VDIM not work!!! Made no sense to me - especially cuz I drove it for 4 months with VDIM working. Well, they reset something and my VDIM works again... except 3 weeks later, my VDIM isn't working again.
I have NO traction control, stability control, etc. I can spin my tires if they are wet way past 80 mph. I can spin out if I want.
So, my question is... is the VDIM linked to the TPMS? If so, why in the world would they disable traction if a tires pressure sensor goes off? Is my VDIM defective? What should I do? Put the winter tires with the TPMS back on?
I actually like the VDIM so don't tell me to live w/o it.
I have NO traction control, stability control, etc. I can spin my tires if they are wet way past 80 mph. I can spin out if I want.
So, my question is... is the VDIM linked to the TPMS? If so, why in the world would they disable traction if a tires pressure sensor goes off? Is my VDIM defective? What should I do? Put the winter tires with the TPMS back on?
I actually like the VDIM so don't tell me to live w/o it.
#2
Super Moderator
Did the dealership read the fault code(s) before they reset it? What did the code indicate? I find it hard to believe that running without TPMS would shut off a vital safety system like stability control.
#4
Tech Info Resource
iTrader: (2)
Actually it makes perfect sense. VDIM is heavily dependent on wheel speed data. If the tire is not properly inflated, wheel speed data is corrupt. It would be foolish to enable a vehicle stability control system operating on corrupt data. So it makes perfect sense that the pressure sensor system failure would turn off VSC and TRAC. The real test to see if it shut off ALL of VDIM is to see if the antilock function on the brakes is still working. The only thing I'd be concerned about (apart from who knows what all is going into limp mode) is the EBFD. The brake system doesn't have a conventional proportioning valve. It uses wheel speed and Electronic Brake Force Distribution (EBFD) to set up brake proportions. I'm not especially fond of the way I've seen it work in my Scion tC but, I don't know what the failsafe is, and I'm not sure I'd like it better.
#5
Why not just put them back on if you're concerned of not having VDIM? If I remember right, the system can accommodate two sets of tires so in your case you can alternate between settings when changing tires.
#7
Super Moderator
In making the assumption that the original poster is not a complete idiot (foolish enough to get the rear of his car loose while traveling 80mph on a rainy road), I figured that the meant that he was able to spin the tires up to an indicated 80mph on the speedo while standing still.
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#8
In making the assumption that the original poster is not a complete idiot (foolish enough to get the rear of his car loose while traveling 80mph on a rainy road), I figured that the meant that he was able to spin the tires up to an indicated 80mph on the speedo while standing still.
#9
11 Second Club
Thread Starter
No, I was just making a right turn onto a 60mph road, spun the inside tire all the way into 3rd gear. The vehicle probably wasn't doing more than 30 mph though.
In any case, called up the Lexus dealer and they told me it might be a gas cap so I checked the gas cap and we'll see if the CEL goes away. If not, another trip to the dealer in the next couple of days.
going back to Lobux's reply - if it makes perfect sense, why didn't the CEL and VSC turn off the first instance that the TPS went off? Why wait 4 months for it to stop working?
Either way, it has been fun driving in the rain w/o VDIM, but I think my rear tires are worse for it.
In any case, called up the Lexus dealer and they told me it might be a gas cap so I checked the gas cap and we'll see if the CEL goes away. If not, another trip to the dealer in the next couple of days.
going back to Lobux's reply - if it makes perfect sense, why didn't the CEL and VSC turn off the first instance that the TPS went off? Why wait 4 months for it to stop working?
Either way, it has been fun driving in the rain w/o VDIM, but I think my rear tires are worse for it.
#10
11 Second Club
Thread Starter
Okay, it wasn't the gas cap. Took it to the dealer again, this time the mechanic said it something else. Definitely NOT the TPMS causing the VDIM to not work. They think it might be the pipe that fills the tank - I will find out Friday for sure.
#11
Super Moderator
Did you ask them to read the fault codes? What were they?
#12
Tech Info Resource
iTrader: (2)
OK, but an EVAP fault would never shut down VDIM, VSC, or TRAC.
Your example of spinning the inside wheel is a clear indication VSC is not working because the documentation says specifically that VSC will use the rear brakes to limit wheelspin in the same sort of way a clutch-type LSD works. If you spun up to an indicated 80 mph, it clearly was not working.
I searched the manuals for any indication the VDIM/VSC/TRAC systems would stop working because TPMS data is bad, and there is nothing I can find to say bad TPMS data puts any of the stability controls off-line. So accurate wheel speed data must not be such a big deal to these systems.
Your example of spinning the inside wheel is a clear indication VSC is not working because the documentation says specifically that VSC will use the rear brakes to limit wheelspin in the same sort of way a clutch-type LSD works. If you spun up to an indicated 80 mph, it clearly was not working.
I searched the manuals for any indication the VDIM/VSC/TRAC systems would stop working because TPMS data is bad, and there is nothing I can find to say bad TPMS data puts any of the stability controls off-line. So accurate wheel speed data must not be such a big deal to these systems.
#13
Tech Info Resource
iTrader: (2)
OK, I found new and better information, straight from the mind of Toyota -
FAIL SAFE OPERATION
• If there is a problem with sensor signals or actuator systems, the skid control ECU prohibits power supply to the brake actuator assembly and informs the ECM of VSC system failure.
The brake actuator assembly turns off each solenoid and the ECM shuts off VSC control (traction control signal) from the skid control ECU accordingly, which turns out to be as if the ABS, TRAC and VSC systems were not installed.
The ABS control will be prohibited, but EBD control continues as much as possible. If EBD control is impossible, the BRAKE warning light comes on to warn the driver (See page BC-43).
• If system components have any malfunction before starting control, immediately stop the operation. If system components have any malfunction during control, gradually stop the control so as not to trigger a sudden change in vehicle conditions. If it is impossible to control the systems, the warning light comes on to inform the driver of termination of the systems (See page BC-43).
HINT:
If the hydraulic brake booster encounters a malfunction, brake performance is gradually lost and ABS, BA, TRAC and VSC systems are prohibited.
• If there is a problem with sensor signals or actuator systems, the skid control ECU prohibits power supply to the brake actuator assembly and informs the ECM of VSC system failure.
The brake actuator assembly turns off each solenoid and the ECM shuts off VSC control (traction control signal) from the skid control ECU accordingly, which turns out to be as if the ABS, TRAC and VSC systems were not installed.
The ABS control will be prohibited, but EBD control continues as much as possible. If EBD control is impossible, the BRAKE warning light comes on to warn the driver (See page BC-43).
• If system components have any malfunction before starting control, immediately stop the operation. If system components have any malfunction during control, gradually stop the control so as not to trigger a sudden change in vehicle conditions. If it is impossible to control the systems, the warning light comes on to inform the driver of termination of the systems (See page BC-43).
HINT:
If the hydraulic brake booster encounters a malfunction, brake performance is gradually lost and ABS, BA, TRAC and VSC systems are prohibited.
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