Engine Check & ICS Malfunction light all on at the same time.

 

Just last night got the ICS malfunction light shortly followed by check engine light. Joined this forum looking for answers since the dealers are closed today, Sunday but not finding anything here. Will keep searching.

 

Found this:
The “ICS Malfunction” warning light indicates issues within the Intelligent Clearance Sonar system. Possible causes include sensor malfunctions, wiring problems, or issues with the control unit. Safety and Driving: Driving with the ICS malfunction warning illuminated is generally safe, but caution is advised.

 

I think that the Sonar System alert is the best clue. Do a search on Lexus Rx sonar system problems. I would first clean all of those sensors on the bumpers. Then I would turn off each of the warning systems and see if the lights goes off. I suspect one of those sensors isn't functioning properly.

 

You didn't tell us the model or model year of your RX. How old is the battery? I suggest having it checked and, if it is close to 4 years old or older, replacing it regardless of test results. A dying battery causes lots of odd behavior in modern vehicles, including the RX. I recently had a battery die and the leading indicator was a parking system malfunction.

 

I’m so glad I found this forum! I have had my 2019 rx350L in and out of the dealership service dept for most of this year. Out of nowhere I would get those same lights and messages about reduced engine power (not fun on major highways) and the car is stuttering as if it’s going to quit…then I get to the dealership and they fix what they think it is…just for me to get my car and it happen again!
this last time I almost had my car 2 full weeks and drove from Fl to SC and back without any issues, I was so happy then BAM! Check engine, master warning light, traction control off and ICS malfunction- visit your dealer.
The code is P0355 and they have already replaced the “E” coil.
I was starting to think my car is possessed!!

 

You need a new repair place and stop going to that dealer as they obviously cannot perform decent diagnostic testing.
Start with this searchable database of shops recommended by listeners of the old Car Talk Radio Show. You can search city and state.
Then because some reviews are very old, cross check potential shops on
Google and Yelp to find newer ratings and other local independent repair shops with great ratings, hopefully one that specializes in Japanese vehicles or Toyotas.
​​​​​​https://www.cartalk.com/mechanics-files

 

I had the same issue recently in my 2019 RX. Apparently there’s a fuel pump recall my car is at the Lexus dealership getting it replaced as we speak. The car tries to stutter because it’s not getting enough gas.

 

ny thanks for your post

 

did you get any answers? I am going through this right now!

 

did you get any answers? I am going through this right now! They said next step is to rebuild engine $5000+!

 

did you get any answers? I am going through this right now!

 

Kristy, do you have the ability to read and then clear codes? If so, I would record the codes, clear the codes and see if they return.

I have had these warning messages before. Two times, the ICS warning has appeared while driving and it was an easy fix by clearing the sensor area - the Lexus "L" on the front grille - as it was just caked with snow.

Another time it happened, while not driving in the snow, and I simply read the codes, recorded them, cleared them, and they did not show up again. I would record when it happens for future reference.

If you do not have a code reader, you can clear the codes another way if you have a 10mm wrench:
* make sure all accessories are turned off: lights, heater, radio, seat warmers, etc.
* disconnect/remove the negative battery connector/cable from the battery terminal
* disconnect/remove the positive battery connector/cable from the battery terminal
* Touch the two connectors/cables together for a minute or two - this simply discharges capacitors, etc. Neither of the connectors/cables are attached to the battery for this task so there is no power source and you will not be shocked.
* Are your battery terminals or connectors in good shape, or are they corroded? Now is a good time to clean them if corroded.
* reconnect the connector/cable to the positive battery terminal, then reconnect the negative connector/cable to the negative battery terminal
* idle the car for 10-15 minutes with all accessories turned off
* drive the car

 

What were the codes?

 

maybe try cleaning the sensors? I found this.



A Lexus Intelligent Clearance Sonar (ICS) malfunction light indicates a fault in the parking assist system, often triggered by dirty, damaged, or misaligned sensors on the bumper, or a weak battery. It is frequently accompanied by "Parking Assist Unavailable" messages and may cause automatic braking issues.

• Dirty/Obstructed Sensors: Clean all parking sensors (small circles on front and rear bumpers) with a microfiber cloth.
• Battery Issues: A dying or recently replaced battery can trigger this warning. Disconnect the battery for 10–15 minutes to reset the system.
• Sensor Damage: Inspect for damage or corrosion on the sensor harnesses.
• Software Glitch: The system may require a calibration update, particularly if the vehicle was recently in a collision or had a bumper replaced.

If cleaning the sensors and resetting the battery does not resolve the issue, a professional diagnostic scan is necessary to identify the specific faulty sensor or module.




To reset the ICS (Integrated Chassis System), first locate the sensors—typically mounted near suspension components or wheel hubs. Disconnect the battery to prevent electrical issues, then carefully clean sensor surfaces with a soft cloth and mild cleaner to remove corrosion or debris. After cleaning, reconnect the battery and perform the reset procedure as per the manual. If the reset fails, inspect sensor wiring and connectors for damage or corrosion. Regular sensor maintenance ensures accurate readings and system reliability.