Lets Drive

iTrader: (3)

CL,

I started this thread to gain some specific information, regarding the pre-collision system on the IS, and in general, how it functions with the normal safety restraint system, due to some issues I'm experiencing. For starters, I'll state my situation.

As described in my signature, I'm the owner of an 06 IS equipped with the pre-collision system, and for the most part, it has behaved 'normally'. I'll define 'normal', as the radar cruise/detection operating fine, while the system activates and restrains. It is during the latter portion of this process, however, that a unique issue arises.

When the car detects that an accident may occur, the system does its thing, and quickly begins to retract the seatbelt preemptively. During this part of the process, within the second that it occurs, the belt mechanism makes a rapid clicking noise (gears), which is more than likely the pretensioner attempting to catch the belt spool. Firmly locked in place, the system has technically restrained me as an occupant, but it remains an abnormal function, and does not occur on the passenger side. Compounded is the fact that upon the situation ceasing, the belt will not release from this locked state, as its supposed to. Even when coming to a full stop, the belt remains taut, disallowing any free movement, meaning I must unbuckle my seatbelt, letting the belt retract in the spool to offer full slack, then re-buckle myself to regain normal mobility in the cabin.

As you’d assume, a malfunctioning safety system isn’t acceptable. I took a look at the thread https://www.clublexus.com/forums/sho...d.php?t=211026, and saw that a generic recall was issued for early model IS vehicles, but it didn’t detail what the issue was, exactly. Has anyone had this seatbelt recall performed, and if so, are you aware of what was replaced?

Also, the dealership is currently diagnosing the vehicle for the 2nd time. The first (and I’ve confirmed with the second), they supposedly simulated a crash incident via computer, but failed to produce any results, and thus, didn’t find any issue to fix. For some odd reason, they don’t believe a brake threshold test in a safe area is necessary, despite the simple physics which dictate that you need some mass (driver), and velocity (moving vehicle/driver), to reliably reproduce what occurs above.

Has anyone else with the pre-collision system experienced the above issue, or any like it, in general? Also, if you have any specific knowledge (or service manual info) on how the system operates with the normal restraint system, it would be valuable as well. I've researched some generic info., but have trouble finding anything specific to Toyota/Lexus.

Otherwise, thanks for reading, and I certainly will be getting this fixed.


Cliffs:

• Loud gear clicking noise when pretensioner from pre-collision activates.
• Belt system does not return slack normally, unless unbuckled.

Gaugster

Well, I have an 07 with PCS. I have only had it activate once when a truck decided to exit a turning lane as I was about to drive by.

It was a while ago but I do not recall any of the issues you list as occuring. I remember the seat belt getting tighter and the brakes grabing more.

In reallity it wasn't even a close call as the brakes worked well but the car returned to normal right afterwards. No loud clicking and the seat belt acted as it would.

Brian231

ETR based restraint or Emergency Tensioner Retractors feature a network of cables that are servo based and once activated via hard braking or algorithmic code based on sensor data read-out, cause that uncomfortable yet, safe feel. I'm gonna make some cheese sandwiches now.