by Bob Beranek
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I received some interesting news recently about 2017-18 Honda CRVs equipped with Advanced Driver Assistance Systems (ADAS) and a rain sensor (FW04540-41). Although I can’t confirm at this time if this glitch applies to all Honda models, if the Honda model you are working on has both ADAS and a rain sensor, then I suspect the following procedure will be necessary when replacing glass in those models as well.

Honda CRV 2017

Honda CRV 2018

Dealers will tell you that all Honda model vehicles will require OE glass be installed before they can be recalibrated. With that being said, those of you who recalibrate with your own purchased tool may find that recalibration is possible with aftermarket glass, if the glass used is of good to excellent quality. The issue is the rain sensor.

If you install an aftermarket windshield, the rain sensor still may not work, even though the recalibration was a success, and even though it worked during the pre-inspection. The reason for the malfunction is what is called the Body Control Module (BCM).

Honda has an instruction note for installation that reads:

  • Make sure that there are no air bubbles between the windshield glass and the silicone sheet during installation;
  • If the automatic lighting/rain sensor connection is connected after the 12-volt battery terminal is connected, the automatic lighting/rain sensor is not confirmed by the body control module;
  • If the body control module does not confirm the automatic lighting/rain sensor, the automatic wiper system does not work.

This means that the BCM must be reset to recognize the lighting/rain sensor. How do we reset the BCM? In this case, the only way to reset the BCM is to disconnect the battery.

I know, disconnecting the battery should be discouraged whenever possible. Disconnecting the battery means that memory systems built into the vehicle can, and in most cases, will be lost. You will have to explain to the vehicle owner the possibility of lost memory to favorite features. However, here’s what needs to be done.

  • Disconnect the negative battery terminal;
  • Leave it disconnected for 15 minutes;
  • Reconnect the battery terminal and start the vehicle;
  • The vehicle will go through a reset protocol and reset the lighting/rain sensor; and
  • The radio can be reset by depressing the power “on” button 3-5 seconds.

After talking to several Honda dealers and dealer glass installers, I have heard that if an OE glass is installed, this BCM reset process rarely needs to be completed. So, you have a choice, stand around for 15 minutes waiting for the BCM to reset, or simply buy OE glass and be on your way. I will let you know when I learn more.

Comments (2)

  1. […] Today’s Blog: Technically Speaking – Honda CRV Rain Sensor […]

  2. Steve Cheney said on 29-01-2018

    Has anyone tested what happens if the rain/light sensor is never unplugged from the harness during the glass replacement (if this is possible)?

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