I bought a 2009 Mk3.5/nc2 SportTech on Saturday and drove it all the way from Plymouth to Worcester (around 160 miles) and the car performed faultlessly with no untoward warning lights.
It has been parked up ever since (other than to move it on the driveway on Sunday morning). I decided to go for a spin after work today and as soon as I started it 2 orange warning lights were showing on the dash. The ABS light and the TCS/DSC Indicator light.
I carried on with my drive hoping that they would reset themselves. I turned the ignition on/off several times although each time the lights stayed on.
The car seemed to drive completely normally with no untoward noises etc.
Hi, is the dcs light flashing or steady? You may have inadvertently pressed the switch, as you can activate/deactivate it and the light would display. ABS? No idea TBH.
I’ve had same on mine after it’s been sat a while and brakes stuck. As I drove off there must have been a sensor issue. I found you need turn off and in and drive again for it to be reset.
Get yourself an OBDII reader and find out what the ECU thinks is wrong, then go from there. There’s a good chance you can reset the codes once you’ve read them and, if they don’t come back, reckon on having to do appropriate work in the near future.
If they do come back, reckon on doing that work right away!
If it’s a MK3 I don’t think a cheap OBD reader will talk to the abs or the seat belt controller modules. Have you tried rotating the steering wheel from lock to lock a few times. It may be that your battery has dropped in voltage and this has disabled the ABS system.
Have you tried starting the engine and while stationary, turning the sterring wheel fully to the right then fully to the left, back to straight ahead then turning off and re-starting?
Thanks everyone for their input. I’ll try turning the steering wheel full lock to full lock to see if that re-sets anything and also I’ll order a code reader.
Forgive my lack of knowledge here, but I thought the ECU would collate that information and show appropriate error codes. Do those modules live independently of the ECU and communicate solely and directly with the dashboard when they have problems?
In short, yes. As vehicles have become more complex individual tasks are performed by discrete electronic modules dedicated to maybe one or a small group of related tasks. The ABS / DSC electronic module is incorporated into the ABS hydraulic system and just outputs the necessary signals to illuminate the dash warning lights, taking input signals from the wheel sensors and the Steering position sensor and maybe a yaw sensor… Same with the SRS module which connects to various sensors on the car to detect a crash situation and then makes the decision which actions to take , ie fire airbag(s), tension seat belts etc etc. The SRS sensor is placed in the safest part of the car under the console usually in the middle of the car. It’s no use having it destroyed in the first few milli seconds of a crash and unable to perform its function. In addition more modern vehicles will have a Body Control and other Modules controlling other functions related to the operation of various convenience features. These bits can be spread all over the car in an attempt to package more and more bits and associated wiring into less space, otherwise you would have a box the size of a desktop computer to find a home for. This is why the CAN bus system for inter module communication was developed
As above, most problems with ABS and traction control warnings are to do with the wheel sensors, also check the wiring to each sensors, they often get damaged or left unplugged when working on brakes and suspension, not just MX5’a, any car.
Had the same problem on my 2009 Mk3.5 a couple of weeks ago. After taking it to a trusted garage it was the brake light switch. apparently this switch does a lot more than put the brake lights on when you press the brake pedal. It’s all connected to the ABS unit (it could have been that, glad it wasn’t) and ECU, wheel sensors, and they all talk to one another when you brake, so I’m told. The problem has not re-occured after switch was replaced. Hope this helps.
If you can find it the Mellens.net Miata / MX5 workshop manual has a comprehensive run down on all the electronic and electrical systems and their parts which can be very useful for troubleshooting.It also includes all the mechanical and body repair procedures as well.
This type of warning can also be triggered by low pressure in a tyre. If the car is driven with a low tyre pressure, the system picks up that the affected wheel has to rotate slightly more often than the others, due to a reduced rolling radius.
Thanks all for the various suggestions, unfortunately having tried them all, the warning lights are still glowing brightly.
I have managed to borrow a fault code reader and established the following:-
C1175 Speed Wheel Sensor Left Rear Input Circuit
So its either a failed wheel speed sensor or a wiring continuity issue. Next I’ll remove the nearside rear wheel and check the wiring and plug and if that seems ok I’ll order a new wheel sensor. Any suggestions as to where to get one from or am I better off biting the bullet and ordering a genuine part from my nearest main dealer?
