Hi all,

I recently purchased (yesterday) a 2009 AWD LWB (LHD). The PCS Light is on due to the A/S being swapped for traditional coil/struts (Strutmaster Brand). I had the vehicle inspected and everything electronic about the A/S is intact, so the tech and I summarized that likely the emulator was dead, or none was installed in the first place.

I confirmed that no Strutmasters “Lights Off” module is to be found behind the glovebox and nothing is spliced or plugged into the suspension ECU.

Strutmaster sells the emulator for $450 USD. I’m in Calgary, AB, Canada, so $450 is like selling my left arm! Eventually I will convert back to A/S just to try both sides of the coin and have an educated opinion on which I like better.

Does anyone have a recommendation or aware of a less expensive module/emulator that performs the same idea of tricking the suspension ECU into thinking the system is operating normal? This way I can enjoy the radar cruise and other options that are currently being held back.


Pic to prove I actually looked!

Any help is appreciated, and I apologize if this has been covered; I swear I did some searching before I posted!

 

Just disconnect the air suspension ECU. If you have AFS, you will have to disconnect its ECU as well, or set left front height sensor to the medium position.

 

If you try a google search with "clublexus" on the end you'll find more results. you could start by checking if you have this switch because I've never heard of the avs actuators turning on the pcs light.

 

I appreciate the reply. I do have AFS; I’d love to keep it going (as I haven’t even had the opportunity to try it out yet).

I’d like a confirmation from you that the A/S ECU is the one on the far right? I disconnect all harness’ (X3 connectors)?

I’ll google how to do the height sensor adjustment. Therefore to confirm, disconnect all 3 connectors and move the height sensor to medium on the front drivers side?

Thanks again.

 

I went and checked and I do not have the switch. I have the TPMS switch and the turn dial. ChatGPT provided me with this when I asked it: “If my Lexus does not have the PCS on/off switch, what does that indicate?” The reply:“If your 2009 Lexus LS 460 L does not have a PCS (Pre-Collision System) on/off switch, it likely means:

1. Your vehicle was not equipped with PCS from the factory – PCS was an optional feature, often bundled with the Advanced Pre-Collision Package, which included radar cruise control and other safety systems.

2. Your vehicle has PCS, but it’s always active – In some Lexus models, PCS is integrated without a manual on/off switch, meaning it’s always enabled unless there’s a system fault.”

I read through the FAQ thread about the 2-Buttons we should all know about, but it didn’t get me any further. However, what I did gather from the thread is that there are multiple sensor locations. The headlights on the car I purchased are extremely UV yellowed, as is the Lexus symbol. Maybe this is the culprit? I’ll be getting a full detail/polish in about a week, but I might try to clean up the headlights/symbol with an Amazon product to try to get to the bottom of this sooner.

Another point I’d like to note is that my Cruise Control does not work at the moment. I couldn’t figure out what that meant, because a lot of guys in the FAQ thread said they had a PCS warning, but their Cruise Control was still functioning. I’m a smidge lost…

 

If you don't have dynamic range cruise or pcs that light shouldn't be coming on, have a look to se if there's a sensor on the rear of the front lexus emblem on the grill. Did the lexus dealer give you a list of any stored codes when they inspected it? Did they tell you the light is on because of the airsus being removed?

 

I have both PCS and Dynamic Cruise. The Vin produced that. Lexus let me know all the sensors are in good working order, but I neglected to ask for the codes. I’ll see if they would provide them, but it’s been two days since the inspection, so I’ll hold my breath…

Lexus told me the code is on due to the A/S being removed, but honestly I don’t fully trust them compared to members on ClubLexus.

Another note to confirm Dynamic Cruise and PCS is that I have the symbol/buttons on the bottom right of the steering wheel with the car with the sensor splayed out for distance choosing and I have the brake hold button on the bottom left.

 

If you have both those systems the light might be on due to the infrared in both your innermost lenses in the headlights being blocked by the yellowing that you mentioned because they are used for the cruise as well as the pedestrian detection that your car uses, you mentioned the cruise doesn't work either...if you can pull the codes which should be there it will give you more info.

 

Hey Gerf,

Lexus Inspection report notes there are no Codes even with the PCS Light on. The tech did write this exact diagnoses: "Confirmed PCS Light is on. Performed health check, no trouble codes related to the condition. Inspected front and rear park sensors, they are working properly. Hoist vehicle and noticed it has aftermarket front and rear shocks, but not equipped with air suspension. This causes the PCS light to be turned on. Recommend to install OEM Front and Rear shocks and connect the air connector."

I just finished performing the 3M headlight restoration kit. The headlights look incredible, so does the Lexus symbol. Unfortunately I still throw the PCS Warning Light. I'll next disconnect the suspension ECU and check the drivers side height sensors and set it to mid.

I see you are in AB. I'm in Calgary. If you have any other ideas, I'm all ears.

 

Did you check the wiring on the lexus emblem sensor ? if any work has been done there it's possible something might have happened, just based on when I got my car I wouldn't really trust the dealer is as capable as they think they are. Does your invoice say they did a health check with techstream?
nm, reread your post,

 

I did not. My assumption is that it’s fine, but I’ll certainly confirm it.

 

Hey Gerf,

Wiring on the Lexus emblem is intact.

I unplugged the A/S Module and the AFS module and now my dash has alternating PCS and AFS warning lights. I plugged the AFS back in and I still have both lights.

Do you figure I need the Lexus/Toyota program in order to clear them? Any thoughts will help.

 

Disconnecting the AFS ECU will effectively disable the system. Are you sure you disconnected the correct module?

 

My car is awd also and I've lowered it about 2 inches all around using the mechanical height adjusters and it didn't affect the headlights in any way or turn on any lights, they may have a single sensor for height on a rwd but I've never owned one of those so I couldn't say for sure. https://www.clublexus.com/how-tos/a/...ring%20springs.

If the AVS actuators on the top of each shock aren't left connected to the electrical connector harness like in the picture from my car you will get some codes and lights if left unplugged so yes if you could check or have someone retrieve the codes it would help. I have a hard time believing the pre crash system light is on with no associated codes like that dealer told you.