I've dealt with the abs pump before...will kick on lights, throw low pressure accumulator codes, and lots of squeaking at idle pressing brake or coming to a stop. The one I am in however, has the following 3 codes: ABS/VSC/TRAC: C1252 (Current) - Hydro-Booster Pump Motor ABS/VSC/TRAC: C1256 (Current) - ACCumulator Low Pressure ABS/VSC/TRAC: C1391 (Current) - Abnormal Leak of ACC Press And I've read about it being a skid control ecu issue or the actuator? The symptoms I have is I am hearing strange noises (but doesn't seem like squeakiness from pump), but main thing is on a cold start you hear a BEEEEP BEEEEEEEEEEP that lasts about 10 seconds or 15 seconds. During the loud beep the brake pedal is hard and not functioning well. Then back to normal when beep goes away. Any ideas before I take to mechanic?
So this seems like a story where the skid ECU is giving you three codes that indicate an impaired ability to pump up and maintain hydraulic pressure, and the question is, are those codes for real, or are they being reported spuriously just because the ECU is faulty? That's not an unreasonable question to pin down before replacing stuff, but in this case, you've also got so if the ECU is somehow delusional and only imagining the hydraulic pressure is low, it has managed to persuade the physical brake pedal to join in its delusion. If there are journals of car psychology, that could be a groundbreaking case study.
Do a quick check on the 12v battery and jump points. Some here believe the pump can or will act up around lower voltages.
Drove too much now constant beep entire time driving never goes away! And brakes funny/hard/dangerous! Taking to mechanic but quick question: is the ecu attached to the pump/actuator? Hate to do all the labor on just the ECU and come to find u have to do it all over again for actuator as my mechanic charging 250 for changing the abs pump/actuator.. Thinking might as well change both out and kill 2 birds with 1 stone if they are attached together. Thought I seen both sold as 1 unit on eBay for $300 so assuming this is the case
All appearances here are that the ECU is perfectly healthy and doing exactly what it is supposed to be doing by telling you about your hydraulic pump problem. Replacing the ECU would be shooting the messenger. Replacing the actuator assembly would be solving the problem. The ECU is not attached to the actuator in Gen 2. (It is in Gen 3. But then in Gen 3, the pump is off in a different assembly.)
Maybe @JC91006 can chime in on this job. Since the labor cost is below average (relatively speaking), you might consider the Dorman product with a 'Lifetime Warranty". No sense in dropping a used actuator in and it failing prematurely, or the mechanic telling you the job was correctly done and claiming the used part that was supplied/installed is bad, leaving you in a having to repay to play situation again. Many have replaced just the actuator without the brake resistor assembly, they may come as a matched pair : Doubtful the ecu is the problem, the brake/skid control ecu is near the brake pedal (heat sinked with a gray plastic buzzer):
I suspect the actuator you put in is a bad part or something got loose. I would check your work again and make sure all the brake lines are tightly secured. When I try to start the car with the actuator removed (no pressure from the brake pedal), I would hear the beeping sound you're describing. I would be very careful buying used actuators online, many people may be selling off the bad units they remove, to recuperate their cost on the part. Buyer beware
Here is the workup for DTC C1252 and C1253 : https://share.qclt.com/%E4%B8%B0%E7%94%B0%E6%99%AE%E7%91%9E%E6%96%AF%E5%8E%9F%E5%8E%82%E8%8B%B1%E6%96%87%E6%89%8B%E5%86%8Cpdf%E6%A0%BC%E5%BC%8F/Repair%20Manual/04pruisr/05/21avn/cic12525.pdf Here is the workup for DTC C1256 : https://share.qclt.com/%E4%B8%B0%E7%94%B0%E6%99%AE%E7%91%9E%E6%96%AF%E5%8E%9F%E5%8E%82%E8%8B%B1%E6%96%87%E6%89%8B%E5%86%8Cpdf%E6%A0%BC%E5%BC%8F/Repair%20Manual/04pruisr/05/21avn/cic12565.pdf Here is the workup for DTC C1391 : https://share.qclt.com/%E4%B8%B0%E7%94%B0%E6%99%AE%E7%91%9E%E6%96%AF%E5%8E%9F%E5%8E%82%E8%8B%B1%E6%96%87%E6%89%8B%E5%86%8Cpdf%E6%A0%BC%E5%BC%8F/Repair%20Manual/04pruisr/05/21avn/cic13916.pdf
We did not put in an actuator. This is an auction car that arrived with ABS/brake light AND a bad hybrid battery. Fixed the battery right away and now contending with brake problem... So if I am reading the page correctly you guys are stating this is most likely an actuator/pump problem.
Done it once on a different car and worked well. Although I didn't know that car-part lists that there are 3 different types of actuators so apparently there is either no meaningful difference between the 3 actuators or we got lucky cause it fixed it (different prius). I can usually tell if the company is run professionally or not by looking at their website, reviews, etc. LKQ for example, has a valuation of $8 billion! They do about $3.5 billion in annual sales and employ around 50,000 people. They are a publicly traded company listed on the NASDAQ. They have good warranties and are a safe choice. That being said, recently bought an AC compressor from them that mechanic said is no good because they cut off that orange wire thingy that comes with it. But they have an easy return policy.
I replaced the actuator for our 2008 Prius. Not wanting to play around with this multiple times and since it was a component on the brake system I bought a new unit form Toyota. Here is the invoice Order Content Part Number 44500-47141 Actuator Assembly $1,134.95 1 $1,134.95 Subtotal: $1,134.95 This is the part number for the upgraded actuator which will not have the same problems as the one you are replacing! My experience- bought a used unit on ebay and sent it back as soon as I opened the box and saw the shape the unit was in got a full refund and went with the brand new Toyota OEM improved unit. If you are fixing this car to flip you are probably going to go the cheapest route.
