Check VSC system (RX400h)

welland · February 28, 2021

While out driving in my RX400h yesterday, the dashboard warning for "Check VSC system" was shown, along with the ABS warning and traction control warning. I could tell that the traction control was activating (incorrectly) as power delivery was being intermittently interrupted and the traction control light was flashing. I was driving on a flat level road at around 40 MPH.

The fault is still reported now, so switching off the car and leaving overnight has made no difference.

I've plugged in my OBD tool and checked for DTCs in OBDAutoDoctor, but there are no faults reported there.

SO, just wondering if anybody with knowledge of these things could suggest possible causes of the fault? Is there a reset procedure that I could try? (The handbook does not mention a reset procedure).

Mihanicos · February 28, 2021

Check the auxiliary Battery condition. Look at the Battery voltage recorded at the freeze frame. If the voltage falls to 10v, you do get the warnings displayed.

Chris.

Greisingel · February 28, 2021

4 hours ago, Mihanicos said:

Check the auxiliary battery condition. Look at the battery voltage recorded at the freeze frame. If the voltage falls to 10v, you do get the warnings displayed.

Chris.

Agree. Little Battery a classic cause of problems. Get the aux batt on a trickle charge overnight.

Techstream? It’s the best for diagnosis. Shows shadow dtcs ie history

ColinBarber · February 28, 2021

6 hours ago, welland said:

I've plugged in my OBD tool and checked for DTCs in OBDAutoDoctor, but there are no faults reported there.

The problem with OBDAutoDoctor is that it only supports industry standard engine error codes. It doesn't interrogate or understand Toyota specific body and non-engine systems/codes.

Toyota's Techstream system obviously does, but there are apps that will also give you the codes such as Carista.

It could be a Battery issue, but I don't expect them to pop up once you are driving about and the Battery is being charged, they normally appears are you try and get the vehicle into 'Ready' mode so it may be something like an ABS wheel sensor playing up.

Greisingel · February 28, 2021

When my RX400H broke down in France it got towed and moved between garages before being loaded and transported back. When I got it back the dashboard had hybrid/VSC/Brake warning lights. I thought it was terminal at the time.

I cleared the hybrid warning by neg Battery terminal. The car drove fine. VSC/Brake warning lights didn’t clear.

In the end I changed brake pads and discs - just because they needed doing. After about 50 miles of regular use while keeping aux battery well maintained the VSC/Brake warning lights just cleared one day.

m4rkw · February 28, 2021

Same lights popped up on my wife's rav4 not too long ago and it turned out to be the brake light switch, cheap and easy fix.

welland · March 1, 2021

12 hours ago, m4rkw said:

Same lights popped up on my wife's rav4 not too long ago and it turned out to be the brake light switch, cheap and easy fix.

How did you know the brake light switch was faulty? Was it because the brake lights were not working when you pressed the brake pedal? I'll check my brake lights later.

ColinBarber · March 1, 2021

There are 70+ fault codes that can illuminate those warning lights, each one typically having multiple causes. I'd recommend you obtain the fault code to help you efficiently diagnose the issue.

m4rkw · March 1, 2021

1 hour ago, ColinBarber said:

There are 70+ fault codes that can illuminate those warning lights, each one typically having multiple causes. I'd recommend you obtain the fault code to help you efficiently diagnose the issue.

Yep. Garage diagnosed it for me. You should (almost) never replace parts from fault codes alone as that’s a quick way to waste a lot of money.

welland · March 2, 2021

Thanks for your replies. Here's an update based upon my observations and investigations so far.

1) My 12v Battery has been really struggling to maintain charge for longer than 3 days over the winter. It has gone flat a few times and I've also been charging it with an external Battery charger. So, I accept the point that this might be the cause of the problem, but, as Colin wrote, would be surprised if this caused the error to pop up while driving.

2) Nevertheless, I drove the car to Halfords to get the Battery tested yesterday and their tester recommended replacement. So, I will get that replaced ASAP to see if that solves the problem. (Where on earth is my Battery invoice for the warranty claim - it's less than 3 years old, I think)

3) brake lights are working normally

4) while out driving yesterday, I found that the fault is being reported intermittently. Sometimes it goes away and all is fine, and sometimes it comes back on and I can feel interruptions to power delivery caused by incorrect activation of traction control.
(Is there a way to manually switch off traction control? I can't find a way to do this).

5) I've looked behind the front wheels to see if there is anything obviously wrong - such as a damaged cable, but all seems well.

6) Before starting the car from cold, the Battery had 11.8 v on my tester. The car started normally and reported the VSC fault. The engine ran for a while, then stopped by itself, as normal. Then, while looking under the bonnet, I was aware of a quiet humming sound - a sort of quiet buzzing from the area of the inverter. This is not a sound that I usually hear. I also noticed that the inverter coolant was rippling on the surface, so I concluded that the sound was from the coolant pump circulating the inverter coolant. Question is this: is such behaviour normal? I can't recall noticing it before? I wonder if the inverter was working hard to charge the 12v Battery from the hybrid Battery, and hence demanding coolant to maintain the temperature at an acceptable level? Does it seem consistent that a faulty 12v Battery could cause the inverter to work harder than normal and force the inverter cooling system to activate like this?

Greisingel · March 2, 2021

Cannot turn off traction control manually.

RX400H does make all sorts of whirring and buzzing noises. It’s like the inside of an electric grandfather clock. All pretty much normal

Inverter coolant tank should show bubbling after driving to op temp Pump is electrically driven powered by HV Battery

welland · March 7, 2021

Batterymegastore has agreed to replace my Battery under warranty, so thumbs up to them. The new Battery is on its way by post and should arrive tomorrow.

Meanwhile, the fault is still occurring intermittently. There are three states that I have observed:

1) no warnings are displayed and the car drives normally

2) the following are displayed: "check vsc", static orange abs light, static orange traction control light. In this state, the car drives normally.

3) as (2), but the traction control light flashes and power delivery suffers interruptions.

Hopefully the new Battery will make a difference and I'll keep you posted.

Greisingel · March 7, 2021

49 minutes ago, welland said:

Batterymegastore has agreed to replace my battery under warranty, so thumbs up to them. The new battery is on its way by post and should arrive tomorrow.

Meanwhile, the fault is still occurring intermittently. There are three states that I have observed:

1) no warnings are displayed and the car drives normally

2) the following are displayed: "check vsc", static orange abs light, static orange traction control light. In this state, the car drives normally.

3) as (2), but the traction control light flashes and power delivery suffers interruptions.

Hopefully the new battery will make a difference and I'll keep you posted.

Well done with the Battery warranty. Let it stand awhile after delivery.

I remember on my old BMW e39 I had intermittent DSC light. Like the RX poor Battery performance caused problems. But in the end, I cleaned up (accumulated mud) from the wheel sensors, replaced worn discs and pads. Problem solved. The RX too may need a proper wheel area inspection. It may be mechanical not electrical.

good luck

welland · March 7, 2021

11 hours ago, Greisingel said:

Well done with the battery warranty. Let it stand awhile after delivery.

I remember on my old BMW e39 I had intermittent DSC light. Like the RX poor battery performance caused problems. But in the end, I cleaned up (accumulated mud) from the wheel sensors, replaced worn discs and pads. Problem solved. The RX too may need a proper wheel area inspection. It may be mechanical not electrical.

good luck

I haven't heard of letting a new Battery stand for a while before fitting. How long for, do you think?

I was going to check about the process for replacing the Battery. Do I just remove the old one and then connect the new one? I realise that I will need to reset the memories for Windows, moon roof, radio, seats, mirrors, steering column.

Greisingel · March 7, 2021

23 minutes ago, welland said:

I haven't heard of letting a new battery stand for a while before fitting. How long for, do you think?

I was going to check about the process for replacing the battery. Do I just remove the old one and then connect the new one? I realise that I will need to reset the memories for Windows, moon roof, radio, seats, mirrors, steering column.

After delivery I would leave settle for an hour or two. If sealed doesn’t really make any difference.

Yes just replace. Go carefully with the posts. I grounded live on mine like a numbskull. It was dark and I was knackered. You shouldn’t be able to as posts are different diameters.

I put a trickle charger on my new Battery to bring it up to full charge. It was lower than expected. Suppose been sitting in warehouse for months

Then I fitted it. Has been trouble free ever since. Touch wood.

Yes moon roof reset. I don’t have one. Windows wind down and keep button depressed for 15 seconds. Steering should come to life. Mirrors and seats memory I didn’t bother with.

What you want to see is warning free dash.

welland · March 8, 2021

At least we don't have radio security codes any more......

welland · March 13, 2021

Good news and bad to report:

The new Battery has been fitted and that went well.

Unfortunately the Vsc message hasn't gone. In fact it's worse:It is no longer intermittent, but alwsys present, and now there's another message too. Check AWD is also displayed. The traction control light flashes constantly and it is difficult to reach speeds of even 30mph.

I have a new obd adapter which should hopefully work with techstream, and I'll try to obtain fault codes tomorrow.

Greisingel · March 14, 2021

https://www.clublexus.com/forums/hybrid-technology/786686-rx400h-error-c1203-vsc-and-abs-lights-on-after-replacing-battery.html

See if any of this helps. The adaptor should be the mvci cable

welland · March 14, 2021

12 hours ago, Greisingel said:

https://www.clublexus.com/forums/hybrid-technology/786686-rx400h-error-c1203-vsc-and-abs-lights-on-after-replacing-battery.html

See if any of this helps. The adaptor should be the mvci cable

I have different error codes......

welland · March 14, 2021

Now that I have techstream working, I have discovered three faults reported in the ABS/VSC/TRC module. They are:

C0200 Front speed sensor RH circuit - Current
C1235 Foreign object is attached on tip of front speed sensor RH - Current
C1241 Low or High power supply voltage - Current

So, wondering if all three of these are related to the "Check VSC" and "Check AWD" messages? C0200 and C1235 seem to be related to each other, and sound like they might be linked to my problems. Can anybody tell me where the speed sensor is located, and a recommended course of action, please?

C1241 seems strange - considering that I have just fitted a brand new 12v Battery.

Herbie · March 14, 2021

You need to drill down in Techstream to find the sub-codes. I think there may be a 'snowflake' icon on the line of the code number that you can click on, or use the 'List' button on the left maybe?

C1241/41 is Low Battery Positive Voltage - INF code 81, 82, 83, 84

welland · March 14, 2021

46 minutes ago, Herbie said:

You need to drill down in Techstream to find the sub-codes. I think there may be a 'snowflake' icon on the line of the code number that you can click on, or use the 'List' button on the left maybe?

Yes, there was a snowflake to the left of two of the codes (no snowflake for C1235). I'll check what can be found from the snowflakes, but I think it looked like sensor readings.

m4rkw · March 14, 2021

Could these be stored codes? Eg the voltage one that you found odd. That could have been set by the computer before you changed the Battery.

welland · March 14, 2021

29 minutes ago, m4rkw said:

Could these be stored codes? Eg the voltage one that you found odd. That could have been set by the computer before you changed the battery.

I thought that too, but all three definitely show as current, not stored.

welland · March 14, 2021

I'm a novice at using techstream, and I can't see how to drill into a DTC to get sub codes. The screen I see is like this:
If I click on the snowflake at the left of the line, or at the bottom of the screen, the same thing happens: Freeze frame sensor data is displayed. If I click on the magnifying glass on the right hand side, it shows a message saying "Malfunction is present"

Should I click on the erase button at the bottom? Is there any precaution I should take before erasing the codes? The on screen warning message reads as per my 2nd screenshot:

I did follow the process to erase the DTCs, but cancelled at the last step as I don't know the implications of proceeding. I did take the recommended step to save data before erasing , (see 2nd screenshot) but I can't see how to read the stored data.