mekelly

My rear driver's side doors electronics stopped working. Neither the window nor lock switch work. I replaced the 'door computer' with one off of a wrecked car that was working before the wreck.

No change. The door is still 'dead'. Someone told me that the door computer needs to be programmed to connect to the cars communication system with a Lexus scantool before it will work.

Anybody know if this is true?

rkw77080

Have you tried disconnecting your negative battery cable (for a few minutes) to allow the computer systems to re-initialize? Also, have you checked the fuse or wire harness to make sure the ECU is receiving power? Which year model is your LS430?
When you say the door is "dead", did you mean the lock and window switches on the rear door do not work? Can you operate the lock and window from the front driver master switches? Can you operate them with the FOB?

Tom57

Are you getting power to the door? Does the door courtesy light, light up?

mekelly

The negative battery cable has been disconnected; no change.

Neither the door lock or window switch nor the driver master lock and window switch have any affect on that door.

The FOB doesn't lock that door. Don't know how to use the FOB to lower the window.

I haven't check the ECU however the 3 other doors work fine. The lock and window switch's work on each door and the driver master switches work for the other 3 doors.

My understanding is that Lexus runs and 'internal network' for these cars (not just simple voltage/no voltage) to control a lot of the door functions. That's why there's a 'computer' (blue control box) in each door. That necessitates reprogramming the new door control computer to 'link' to the internal network.

Trying to confirm that's the case as I am about 99% sure the replacement box I put in is functional.

Lavrishevo

iTrader: (1)

As Tom mentioned, always check for power to your computer or component before you replace it. Also, the switches at the door can be removed and disassembled very easily. Check them if you have not.

rkw77080

I agree with others that you may not have power at the door. Let's start our troubleshooting there...

Please go to your passenger-side fuse box and look for a 20A fuse called "RR DOOR RH" for the rear driver-side door (you'll also see a "RR DOOR LH" for the rear passenger-side door). Check to see if it's blown. Please let us know what you find...

Press and hold down the "UNLOCK" button on your FOB for about 5 seconds.

mekelly

I checked fuse #38 (RR DOOR RH) and it's not blown (checked continuity with a meter). Also checked fuse #32 (RR DOOR LH) and it's not blown either.

The light comes on above the rear passenger side door so it appears to be getting power.

Tom57

I'd check at the ECU connection as well to verify power at the component. I seem to recall the need to "flash" a door ECU to communicate with the main ECU on the electronics, analogous to programming a new key fob. What led you to diagnose the door ECU as your problem?

Tom57

The light ABOVE the door is not part of the door circuitry. Does the courtesy light at the BOTTOM of the door itself light?

mekelly

The light at the bottom of the door does not light up when the door is opened.

When this first happened I contacted someone I knew who worked as a tech at a Toyota dealership. He said it was probably the door ECU. I purchased a used one from a wrecked car (that was working at the time) and installed it. No change.

My buddy said he thought the new door ECU needed to be programmed into the main ECU as they run a mini internal network for communications.

He moved out of state before I could follow up with him and I've lost his contact info.

I may need to call a dealer and see what they'd charge to flash it.

Tom57

In addition to calling a Lexus dealer, call a Toyota dealer as well. You may be surprised at the price disparity.

Tom57

I asked this question on another CL thread last summer, and the answer I got from someone who has Toyota Techstream was this: Techstream does not "flash" door ECUs to the main communications ECU. Techstream sets various user preferences for features and options on vehicle.

rkw77080

Did your friend mention pulling a DTC? B1216, perhaps?

mekelly

He didn't actually pull a DTC but this would definitely confirm it's not communicating! I assume you need a high end scan tool to get this Lexus specific code. I have a $250 Actron but it's not seeing any codes.

Lavrishevo

iTrader: (1)

I have the Toyota Techstream software and USB - OBD2 dongle. I am in Atlanta. PM me if you want we can hook it up and see if it pulls anything and or program anything. What I was referring to is using a multimeter and making sure you are getting 12v DC to the ECU in the first place but if you meet me at my home you can play with Techstream all you want.