mrmonster

Hi guys,

As the title states, ASF Off started to flash on my '07 RX, it started out of the blue with no touching of anything on the car.

I still see both horizontal and vertical movement at start-up initialization, but I'm not sure if the vertical goes as high as before.

What's the proper way to trouble shoot this issue? I'm hoping it's just the sensor at the back of the car that maybe got "lose" during the salty winter driving.

Rainbird

You need to reset the AFS ECU. This is best done with an intelligent tester (think dealership).

mrmonster

Would battery pull clear the code ..then see if it comes back?

Rainbird

It wouldn't hurt to try. There is another way that involves having the front wheels perfectly straight and pressing the AFS Off button in a certain series, but I can't seem to locate the writeup. If I find it I will post it.

mrmonster

I'll try pulling the battery, but if that doesn't work the diy reset would be awesome. Dealer charges like $130/h so I definitely don't want to go that route just to find out what's wrong.

Rainbird

I found it and as you can see this is definitely not as easy as using an intelligent tester. This is strictly your DIY if you choose to do so. Let us know how this goes.

AFS ECU RE-INITIALIZATION (WHEN NOT USING INTELLIGENT TESTER)
NOTE: This operation manually initializes the steering sensor when AFS operation is not normal due to abnormal automatic correction after completion of AFS INITIALIZATION.
HINT:
 *If it is necessary to initialize the steering sensor when not disconnecting the battery, it is also possible to re-set the signal from the steering sensor.
 *When the centering point memorized in the steering sensor differs from the normal point, the AFS ECU malfunctions. In the case, re-initialize it.
 *If the operation does not finish within a specified time period, the system goes off the AFS indicator light and starts steering neutral point automatic correction.
1. SHIFT TO INITIALIZATION
a. Engine is running and shift range is in the P position.
b. Press the AFS OFF switch eight times at approximately one-second interval (once for ON and once more for OFF, i.e. 4 times ON and 4 times OFF).
 *The AFS OFF indicator light starts to blink twice per second.
 *Initialization can be started when the AFS OFF switch is either in the "ON" or "OFF" 
position.
 *When the AFS OFF switch is pressed eight times, it will return to its original state.
2. INITIALIZATION OF AFS ECU
a. Turn the steering wheel to adjust the tires so that they point straight ahead.
b. Do not change the steering wheel position. Press the AFS OFF switch twice (once ON and once OFF). 
HINT: 
 The AFS OFF indicator light stays lit for two seconds. 
 When the AFS OFF switch is pressed twice, it will return to its original state.
c. Do not change the steering wheel position and press the AFS OFF switch twice within 3 to 10 
seconds. HINT: 
 The AFS OFF indicator light stays lit for two seconds. 
 When the AFS OFF switch is pressed twice, it will return to its original state.
d. Do not change the steering wheel position and press the AFS OFF switch twice again within 3 to 10 
seconds.
3. CHECK COMPLETION OF AFS ECU INITIALIZATION
a. When the initialization of the steering sensor signal is completed normally, the AFS OFF indicator light goes off, comes on, or blinks depending on the specific condition 3 second after the indicator light goes off.

RESULT REFERENCE CHART
HINT:
 Failure to complete initialization. Proceed to step 2 within 10 seconds.
 If 10 seconds elapse, the system starts steering neutral point automatic correction.

mrmonster

Wow those look like nuclear launch codes

I'll give it a try later today, thanks.

mrmonster

No luck.

I couldn't get the reset procedure to work. Pressing the switch 8 times did not change the flashing pattern, no effect.

Pulling battery didn't work either.

I'll be putting on the summer wheels next weekend so I'll check the rear sensor at that time.

If anyone has had experience with the same issue I would appreciate any info.

Symptoms:

- AFS Off flashes every second
- lights go through in/out (left and right) motion, then up ..but not down like before


Thanks

mrmonster

Found the problem, the link between the sensor and suspension broke, one of the ball joints totally seized up.

Looks like this little piece can't be purchased separately so I'll have to build something.

marlexus

i am having the same issue now ... have you had any luck fixing ithe AFS ?

mrmonster

Fix for broken link due to seized ball joints is simple.

Two of these rod end bearings




And a piece of threaded rod to build the link




Then all you need is to cut the threaded rod to length so that the overall length is the same as the old one. Will do this over the next couple of days, weather permitting.

robbyk

Where did you buy them?

mrmonster

Threaded rod will be at home depot, the mini "ball joints" you can buy online or probably harbour freight for you US guys.

scorpboye

The above procedure omits some important steps. You need to turn the steering wheel somewhat to the left and right, and then dead center to re-initialize the AFS. I followed the script below and it turned off my flashing AFS light.

"AFS ECU memorizes the steering position at the time of re-supplying electric power as an initial position. So, in case of performing any operations involving re-supplying of electric power to AFS ECU (such as removing and reinstalling of battery and AFS ECU), it is necessary to initialize the steering position at all times. At this time, AFS ECU flashes AFS OFF indicator light and informs the driver that the initialization of the steering position is necessary. Perform the initialization of the steering position by following the procedure below.

1. With the ignition switch on, turn the steering wheel to the right or left at its most, and under this condition, press AFS OFF switch twice.
2. Turn the steering wheel to the opposite direction of the step 1 at its most, and under this condition, press AFS OFF switch twice.
3. Turn back the steering wheel to the straight-ahead direction, and under this condition, press AFS OFF switch twice.
4. After finishing the above operation, and if AFS OFF indicator light goes off, the initialization of the steering position will be completed.

For the details of steering position initialization, refer to 2004 LEXUS RX300 Repair Manual (Pub. No. RM1027U)."

Since the ignition is only in the "on" position, no power is going to the power steering system so "at its most" means turning the steering wheel as far as you can left or right. For me it was no more than 45 degrees in either direction. Hold the steering wheel left and press the button twice. Then right... press the button twice. Then center the wheel before you once again press the button twice to finalize.

Then I turned the car on (running) and followed the 8 button presses of the AFS switch and my AFS light has stayed off for the past couple of days. The AFS light can flash to indicate problems with various sensors that feed the system. Mine required initialization of the swivel function after a battery pull, while in your instance mrmonster your height sensor link broke, giving a false reading to the AFS for height.

Hope this helps. btw, I found a rx330 in really good condition a couple of months ago so I bought it. The car is my first experience with anything from Lexus/Toyota (coming from Audi) and the blinking AFS light has been my *first* DIY problem with the car. (after a replaced leaking headlight assembly and rear wheel bearing failure)

See the following attachment for more info.
RX330_AFS_light_373.pdf

mrmonster

I finally found the time to do build the new link. The little ball joints I had used fine threading so I couldn't use generic threaded rod, instead I used two bolts and cut the threads then joined them.

All the parts



Put together



Installed (love those salty Canadian winters)