Hi, I have a 2002 Lexus lx470. The abs light and the brake warning light have come on and there is a continous beeping. Diagnostic code was c1256(Accumulator low pressure switch malfunction). The brake booster pump does not seem to be working. The car had other problems before. Like the passenger side windshield area used to leak water on to the ecu and other relays and the car would start by itself.(Its a right hand drive vehicle). Now that has stopped.
Code is c1256(accumulator low pressure malfunction)
March, 16, 2012 AT 6:29 PM
Did you recently had brake job? Your possibilities here could be the accumulator, ABS motor, or the pressure switch.
March, 17, 2012 AT 4:25 AM
Yes I have changed the brake pads recently. Where is the accumulator located?
March, 17, 2012 AT 6:12 AM
The accumulator is within the hydraulic brake booster-
Did you bleed the brake if so its probably not done right also have you tried erasing the code with a scantool
BLEEDING BRAKE SYSTEM
CAUTION: Wash off brake fluid immediately if it comes into contact with a painted surface.
NOTE: If any work is done on brake system or if air in brake lines is suspected, bleed air from system. When bleeding, keep amount of fluid in reservoir between Min. And Max. Use only SAE J1703 or FMVSS No. 116 DOT 3 brake fluid.
NOTE: If hydraulic brake booster has been disassembled, or if reservoir becomes empty, bleed hydraulic brake booster. See HYDRAULIC BRAKE BOOSTER.
Fill reservoir with brake fluid.
Connect a vinyl tube to bleeder screw on brake caliper and place other end in a clear jar.
Depress brake pedal several times, then loosen bleeder screw with pedal held down.
When fluid stops coming out, tighten the bleeder screw to specification. See TORQUE SPECIFICATIONS.
Release brake pedal. Repeat steps 3 and 4 until all air in fluid has been bled out.
Repeat procedure to bleed air out of brake line for each wheel.
HYDRAULIC BRAKE BOOSTER
With Hand-held Tester
Turn ignition switch off and depress brake pedal more than 40 times. When pressure in power supply system is released, reaction force becomes light and stroke becomes longer.
Turn ignition switch on and check that pump stops after 30-40 seconds. If pump does not stop, repeat 1.
With ignition switch on, bleed right and left front brake calipers and then right and left rear. See BRAKE LINE.
Turn ignition switch off. Connect LEXUS hand-held tester to (DLC3). See Fig. 2.
Turn ignition switch on and select "AIR BLEEDING" on hand-held tester.
Select "FR LINE", depress brake pedal and hold it to bleed right front brake caliper. Repeat until there are no more air bubbles in fluid.
Select "FL LINE", depress brake pedal and hold it to bleed left front brake caliper. Repeat until there are no more air bubbles in fluid.
Select "RR LINE" and repeat procedure for right rear brake caliper and "LR LINE" for left rear.
Clear DTC. See CLEARING CODES under SELF-DIAGNOSTIC SYSTEM.
March, 17, 2012 AT 6:05 PM
Bled the brakes. Light has gone out. Thank you
March, 17, 2012 AT 7:21 PM
June, 21, 2014 AT 1:17 PM
I am having the exact same problem with my 2002 Lexus LX470, but I am not a mechanic and my mechanic says it's something the dealer can only do. Please help!
June, 23, 2014 AT 11:06 AM
Hi, in my case it was due to the acuumulator fault. According to my knowledge the accumulator sends the brake fluid to the pistons located at the wheels at a certain pressure. If it fails, the brake fluid will not reach the pistons and brakes will not work or work inadequately. Either than or there is air in your system which is causing the trouble. The accumulator is nothing but a motor with the brake fluid reservoir on top of it. Switch on your ignition in the morning and listen to the motor whirring away for 2-5 secs. Then it should stop. If there is no sound that means your accumulator is bad. If the whirring noise does not stop, them maybe the brake system has air
July, 28, 2014 AT 7:40 AM
I am having the same issue with my 2005 lx470. I recently had my brake pads and rotors replaced. Did the repair shop do something wrong? Should I take my vehicle to the dealership instead? Please help. Need advice.