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Newbie looking for advice ABS lights on after servicing suspension

Discussion in 'Newbie Forum' started by Mike Campion, Jul 14, 2013.

  1. Mike Campion

    Mike Campion New Member

    Joined:
    Jul 14, 2013
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    Vehicle:
    2006 Prius
    Model:
    Two
    I am new to PriusChat and seems there is good advice on here.

    I have a 2006 T4, 140,000 miles on it, has full dealer history and has never been a problem until now. Had an awful grinding noise under braking from the front left, was worn control arm bushes so, having a reasonably kitted out workshop I replaced various components and brake pads while I was at it.
    Now I am mechanically minded, aerospace engineer by trade and cars as a hobby.
    After carrying out the works, powered up the Prius and the ABS, VSC and red brake warning lights are on. Also under braking pulls heavily to the right, i.e. the front left brake caliper seems not to be working. Now there were a couple of issues while doing the suspension job, the drive shaft popped out of the transaxle - popped it back in easily enough but I am unsure if it went in at the same point or I rotated the wheel. So the first question is there a sensor that monitors the driveshaft position in the transaxle?
    Secondly, while replacing the brakepads the front left caliper was rock hard and I took care the ensure the brake fluid reservoir was open etc etc before compressing the caliper piston. It took some time to 'give' and moved back eventually. Have I caused damage via the ABS actuator? I have since bled the circuit and the brake piston moves statically OK but not under normal motion.
    The speed sensor is OK and there is 5v dc power at the connector. However using the maintenance mode I have noticed the battery (original) is down to 10.2V. Goes to 14V when powered up so Inverter is OK, but within a minute of power off the battery drops to 10V. Do I understand correctly that a knackered battery causes a number of faults on Prius's??
    Any advice would be appreciated as it seems it is quite a job accessing components on these.
     
    #1 Mike Campion, Jul 14, 2013
  2. 2k1Toaster

    2k1Toaster Brand New Prius Batteries

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    Location:
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    Vehicle:
    2006 Prius
    Model:
    Three
    Brakes on the Prius are NOT for the backyard mechanic unless you know what you are doing. The system is never off unless you actually disable it.

    Did you put the ECB into "Invalid Mode" before you started the procedure? I assume you do not have a Toyota Techstream, which is the recommended way to disable the system.

    For future reference you have to do the following within 1minute:
    1. Turn the power switch on (IG) with park (P) selected and parking brake applied.
    2. Select N and then depress the brake pedal more than 8 times in 5 seconds.
    3. Push the P position switch and then depress the brake pedal more than 8 times in 5 seconds.
    4. Select N and then depress the brake pedal more than 8 times in 5 seconds.
    5. Push the P position switch.

    Then the yellow brake warning light "( (!) )" will start blinking.

    Once in this mode, it is very easily kicked out of that mode if you do any of the following:

    The shift lever is used to select from P to any other position.
    Turn the power switch on (READY).
    Turn the power switch off.
    The parking brake is released.
    The vehicle velocity is not 0 km/h (0 mph).
    If you rotate the brake disc at all
    When replacing the brake fluid from the brake line, do not depress the brake pedal to operate the brake
    booster pump more than 100 seconds. If the brake booster pump is operated more than 100 seconds,
    ECB (Electronically Controlled Brake system) Invalid Mode is automatically finished and the DTCs
    may be stored.

    As to the battery, your battery is waaay dead. Having said that it is still usable for a long while. It probably has a shorted internal cell, just like mine. As long as you don't mind inevitably winding up unable to start the car one day, nothing too bad will happen. It will run hotter and might cause random errors on the first few seconds of startup before the inverter starts to regulate.

    The Prius is not a basic car, and you have to know what you are doing. You are lucky the caliper piston didn't shoot out and get lost or impale you. It is pretty pressurized and the accumulator pump sometimes just decides to run, many hours after the car has been turned off, multiple times. The Prius really ever only goes into standby, it is still thinking up to 18hours after being unREADY'd.
     
    #2 2k1Toaster, Jul 14, 2013
  3. Mike Campion

    Mike Campion New Member

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    Vehicle:
    2006 Prius
    Model:
    Two

    Thanks for the reply, appreciated.

    You are right that the Prius isn't a basic car and is quite complex. I have checked all fuses, battery replaced, no air in hydraulics but still have the ABS, VSC and red brake warning lights on. Everything works perfectly other tyhan the front right caliper doesn't appear to operate at full pressure under normal use.

    I wonder if by pushing the piston back during the pad change I have damaged the ABS Actuator? The problem is it is behind the Inverter Assembly, bit of a pig to get to.....

    I have no fault codes on the DTC.

    Looks like a trip to the main dealer to have it diagnosed but at £90 per hour it may not be financially viable to fix it. Bit of a shame as it has been spot on up until now.

    Is there a procedure where I could diagnose the brake fault myself?

    thanks in advance.

    Mike
     
    #3 Mike Campion, Jul 14, 2013
  4. 2k1Toaster

    2k1Toaster Brand New Prius Batteries

    Joined:
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    Vehicle:
    2006 Prius
    Model:
    Three
    Well if you didn't follow the directions, any one of a number of things will tell the computer there is a braking fault. After that happens you will get no regenerative braking, and depending on the codes, it just might not work properly. First thing I would do is just clear the system. Use a code reader to force a clear, use the paperclip method, or just remove the 12v battery for a few minutes. Just a reminder removing the aux battery you will lose your presets, tip odometer, automatic windows will have to be reporgrammed, average mpg or l/100km all of that. If the codes come back on and persist then there is definitely a problem. Otherwise you might be chasing a non-existant ghost and the symptoms are because of the lights, the lights are not because of the symptoms.

    It is entirely possible you damaged something like the piston or the wheel speed sensor or who knows.

    Here is an excerpt from the service manual:

    Basically if the ECU, sensor, or actuator are damaged they won't be used in braking by choice by the EBC ECU. However in accordance with laws around the world in the event of a total system failure the car must still be able to be stopped. Easy enough to check. Get up to a speed that will allow you to hard brake for a couple seconds, preferably in a large abandoned parking lot or something, and then brake HARD. Apply at least 500newtons to the brake pedal (112 pounds of force) like you would in an old car with no power brakes. If it still grabs to the one side then even manual activation was not achieved and there is something definitely wrong.
     
    #4 2k1Toaster, Jul 14, 2013
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