Steelwheel

Had Trac 43 and ABS 54 codes with TRAC light since purchasing 11 months ago. After referring to many helpful forum threads, a tech manual, and Toyota training documents online, I figured the ABS/Trac/Brake system may not have been bled properly after work on it was performed. Also, I wanted to verify the bubbled hose connecting the accumulator/pump was not a problem since it made no sense that it could be "sucking" air through a slightly weeping high pressure hose.

Using the tech manual to bleed the system, I realized how easy it would be to screw it up. Also, components may look bad just because it was not being bled correctly. After properly bleeding the system, quite a bit of air came out of the TRAC actuator (this is on the right side). The accumulator (on the left side) did not have any air and the fluid was crystal clear even though I had the dreaded bubbled pressure hose.

Here is where I think the bleed procedure could cause a misdiagnosis leading to unnecessary component changes.

The manual says to first bleed the accumulator (on the left side) by starting the engine which they say "allows the Trac pump motor to operate". After looking at other documentation, it seems that there is an SST which is suppose to be hooked up to the pump motor to operate it. Instead of using the SST, it is easy enough to jack up the rear wheels and have someone push on the throttle to engage the pump. This definitely starts the fluid bleeding from the accumulator.

Moving to part two: Bleeding the TRAC actuator (on the right side) by starting the engine which should automatically start the bleeding process upon starting. Initially, I started the car then opened the bleed screw on the actuator which nothing came out. Then I looked again and the manual said to loosen the bleeder plug before starting the engine which did the trick. Air and fluid came out quickly.

The trac system has worked perfectly for a month of everyday driving.

If you are getting a 43/54 trouble code, I would suggest a proper brake fluid flush and bleed (by the book) which includes TRAC/ABS in the proper order. It just may help save changing out components that are still good.

pishta

I got a 92 SC400 from my dad who told me last year that the TRAC was making noises since he bought it on 07. I started it up and sure enough there is a high pitch groan for about 7 seconds then the TRAC light comes in. Sounds like an electric fuel pump but more harsh. Now that I own it and Im aware of the bleeding procedure, I cant get the TRAC pump to do anything. Seems its a random occurance, like every 10 starts itll give me the groan. Is there a way to manually actuate the TRAC pump, ie raising the rear tires to cause a sensor to see the rear wheels spinning and not the fronts? Also wouldnt the recent smog check trip the same code when it was up on the rollers and the fronts were stationary? I dont have a CEL lit and the TRAC only lights up when I get the groan at random start up. Most of the time it actually goes away after a few miles when it does trip. What does the STT do to jump the pump? Any leads I should jump in the harness to manually actuate the pump? I tried to bleed the pump side (pass) but all I got when it was cracked open (at no run) was a small residual spurt of fluid that about hit the hood, no pressure at idle.