Ahc Blinking Off

[smagna]

Hello,

I have a 2001 LX470 which i bought used a couple years ago and which has had AHC issue after issue. About 3 months ago, i finally bit the bullet and replaced all 4 accumulators for the second time in 2 years. No one other than i has serviced the truck in the last 2 years so i know no fluid other than the genuine Toyota AHC fluid has been in the system.

For the past 3 months, the ride has been great. It even continues to be great now. However, last week the AHC light began blinking on and off and the AHC system has now failed to operate.

I have checked the fluid level. Its fine.

I flipped the ride quality switch to all positions. Nothing.

I pulled the battery cable hoping the whole system would reset. No luck.

I jacked up the front end hoping the weight off the tires might help the pump if it had weakened. Nope.

There has been lots written on the forum about the accumulators, but i can't find anything on the rest of the system.

The only thing i have not tried yet is to jumper 12v right to the pump to see if it make any sounds of life at all.

Any ideas (other than "take it to the dealer") would be greatly appreciated.

Thx

[Texasoil]

you need to pull the error code(s) that have caused the system to shut down (or have them read by the Dealer for you) Many things can cause the fault. I have been hearing quite a few problems with the pressure sensor failing. THat will cause the pump to shut off and the system to stop. Dealers seem to think replacing the pump assembly (for $3-4,000) is the first thing to do in this case. WRONG. Several things will cause the pump to shut off or stop after a few seconds.

Try putting 12 v directly to the pump and make sure it is not a dead motor. Relays do fail. Pressure sensors do fail. Connections do fail. Pumps SELDOM fail.

Go to my web site (activesuspensionsystems.com) and read all about the AHC system