Only driver door will unlock, help

[grinchy]

Would you happen to have similar codes from your techstream?

5/14/24 b1206 b2281 b2321

P/w master sw ecu communication stop

P signal

D-door motor ecu communication stop

My tech steam laptop is a 2008 netbook and pretty non functional. I need to get the wireless dongle and an image that will run on my MacBook Air. That’s the long way of answering that I haven’t looked for codes for the window issue.

I’m not suffering from central lock issues.

 

[highfructose]

This may be a complete 145 page wiring diagram for an lx570. It may be possible to trace electrical issues with it.

Door lock wiring diagram appears to be 71, 72, and 73

http://myfirewood.com/LEXUS/LX/rm2452e/PDFs/ElectricalWiringDiagram-Overall.pdf

 

[highfructose]

It’s looking like I’ve now lost the following functions:
-Pass, rear pass, rear driv door power unlocking (power locks all still work, driver side power lock works…this used to be intermittent only in the morning)
-turn signal “blink” upon locking of all doors
-intermittent automatic rear lift gate function (open and close)
-automatic headlight activation (in dark/rain)

 

[highfructose]

Update:
I downloaded a wiring diagram (linked above) and legend (attached)

While “searching” for access to the main body ecu, I guessed maybe it’s what the main bundle of wires from the engine bay into the cab plugs into (based on its location and the bundle’s location).

I inspected the grommet between the cab and the engine bay for moisture-none.

However, I have two separate sets of wires (arb compressor switch and aux light switch) that both penetrate (small hole) that grommet…and fit in between the grommet and the hole…that’s how I routed them into the vehicle.

So I tried manipulating those wires…spinning the grommet slightly, moving the extra wires to the top, etc.

And now my door (power)unlocking appears to work again.

Though I appear to have lost the “automatic” headlight activation…so the vehicle doesn’t turn the headlights on at night or when the wipers turn on anymore.

 

[bloc]

Update:
I downloaded a wiring diagram (linked above) and legend (attached)

While “searching” for access to the main body ecu, I guessed maybe it’s what the main bundle of wires from the engine bay into the cab plugs into (based on its location and the bundle’s location).

I inspected the grommet between the cab and the engine bay for moisture-none.

However, I have two separate sets of wires (arb compressor switch and aux light switch) that both penetrate (small hole) that grommet…and fit in between the grommet and the hole…that’s how I routed them into the vehicle.

So I tried manipulating those wires…spinning the grommet slightly, moving the extra wires to the top, etc.

And now my door (power)unlocking appears to work again.

Though I appear to have lost the “automatic” headlight activation…so the vehicle doesn’t turn the headlights on at night or when the wipers turn on anymore.
View attachment 3662080

Is it possible you damaged the wire harness while running those accessories through the grommet?

 

[highfructose]

Is it possible you damaged the wire harness while running those accessories through the grommet?

I don’t think I damaged it, persay…at this point I think I may have had some electrical interference or pressure on the wires that run to the main body ecu being touched by my aux or compressor wires…

I don’t know though…it’s odd that I’ve reacquured locks even after torrential downpours..even in the morning following the jostling of those wires…odd that I also have now lost automatic headlights.

Might just be jostling the harness that (I think) leads to the main body ecu “fixed” it

 

[bloc]

I don’t think I damaged it, persay…at this point I think I may have had some electrical interference or pressure on the wires that run to the main body ecu being touched by my aux or compressor wires…

I don’t know though…it’s odd that I’ve reacquured locks even after torrential downpours..even in the morning following the jostling of those wires…odd that I also have now lost automatic headlights.

Might just be jostling the harness that (I think) leads to the main body ecu “fixed” it

Thing is, jostling wires shouldn't do anything to the function of the harness unless those wires are damaged.

 

[highfructose]

Thing is, jostling wires shouldn't do anything to the function of the harness unless those wires are damaged.

You could be right

I’d really like to be able to get that main body ecu out to inspect it, it’s harness, and the wires around it.

Since the door locks now work, I haven’t had the incentive to continue with tearing into the dash to get to it…other chores and projects are in front of it so long as the doors are functioning

They might stop working tomorrow though, who knows…then:

next step is for me to print out the wiring diagrams, re-learn how to read them (it’s been 15 years or so since I had to read wiring diagrams for a repair) and start working my way back from the “unlock” circuit in the passenger doors to wherever it originates.

If it all flows from that ecu (as opposed to from ecu to relay to door locks), then I’ll likely purchase a used ecu (not spending $900 on a new one unless I have to), install it in the truck, and then send my old ecu to be repaired and kept as a spare.

While in there I can also look closely at the wires to see if there’s damage.

 

[22RE3URFE]

Were you ever able to figure this out? My 2011 LC is showing very similar symptoms to yours. 211k miles.
- only the driver's door and rear hatch will unlock from the fob, driver door switch, individual door switches, or exterior button on rear hatch
- all doors will lock normally
- sometimes I get eight beeps in a row from the vehicle when trying to unlock/lock from the fob
- fuses seem to look good
- I played with the door lock settings in the nav unit, that didn't help
- when this first happened and again once after that my hazard flashers went on spontaneously/while I was starting the car
- the two codes I see when I scan the vehicle with Carly are for the HVAC Climatronic:
1. B1421 - Description is CD player operation fault but the CD player seems to work just fine
2. B1424 - Description is ECU internal fault but it is a malfunction in the Solar Sensor Circuit (Driver Side)

Edit: I just tried disconnecting the battery for 15-20 minutes and reconnecting. The problem persists. My suspicion is the same as yours, that the MAIN BODY ECU (COWL SIDE JUNCTION BOX LH) is faulty. I am going to try a couple more things before I work on removing it. Then I will confirm the part number if possible and order a new or used one. Or I will try to have mine fixed locally somehow, we have an old school electronics repair shop in town.

This problem seems to happen in other Toyota models more often, either due to a higher fault rate or higher production numbers. There is a guy on eBay who sells a kit that will modify the ECU so that anytime the driver's door unlocks the other doors will trigger and unlock. This removes the functionality of unlocking only the driver's door but I don't use that function anyway. Otherwise, it solves the problem. I reached out to him but he didn't seem to have any interest in developing a kit for the LC200.

I did replace the windshield trim recently but I was especially careful on the driver's side, I don't think this is related. I still have to pull back trim and check for moisture but I am betting the recent cold weather has more to do with this.

 

[highfructose]

Were you ever able to figure this out? My 2011 LC is showing very similar symptoms to yours. 211k miles.
- only the driver's door and rear hatch will unlock from the fob, driver door switch, individual door switches, or exterior button on rear hatch
- all doors will lock normally
- sometimes I get eight beeps in a row from the vehicle when trying to unlock/lock from the fob
- fuses seem to look good
- I played with the door lock settings in the nav unit, that didn't help
- when this first happened and again once after that my hazard flashers went on spontaneously/while I was starting the car
- the two codes I see when I scan the vehicle with Carly are for the HVAC Climatronic:
1. B1421 - Description is CD player operation fault but the CD player seems to work just fine
2. B1424 - Description is ECU internal fault but it is a malfunction in the Solar Sensor Circuit (Driver Side)

Edit: I just tried disconnecting the battery for 15-20 minutes and reconnecting. The problem persists. My suspicion is the same as yours, that the MAIN BODY ECU (COWL SIDE JUNCTION BOX LH) is faulty. I am going to try a couple more things before I work on removing it. Then I will confirm the part number if possible and order a new or used one. Or I will try to have mine fixed locally somehow, we have an old school electronics repair shop in town.

This problem seems to happen in other Toyota models more often, either due to a higher fault rate or higher production numbers. There is a guy on eBay who sells a kit that will modify the ECU so that anytime the driver's door unlocks the other doors will trigger and unlock. This removes the functionality of unlocking only the driver's door but I don't use that function anyway. Otherwise, it solves the problem. I reached out to him but he didn't seem to have any interest in developing a kit for the LC200.

I did replace the windshield trim recently but I was especially careful on the driver's side, I don't think this is related. I still have to pull back trim and check for moisture but I am betting the recent cold weather has more to do with this.

Yes, I jiggled the wires where they go into the cab from the engine bay and connect to the body computer. I think it’s An easily perturbed junction and that after running other wires into the cab for a compressor and fog light switch, things must have been pressing on the wires and causing malfunctions. No issues w this since messing w that area.

 

[22RE3URFE]

Yes, I jiggled the wires where they go into the cab from the engine bay and connect to the body computer. I think it’s An easily perturbed junction and that after running other wires into the cab for a compressor and fog light switch, things must have been pressing on the wires and causing malfunctions. No issues w this since messing w that area.

Hm, interesting. Thanks for getting back to me and I'm glad to hear you found a solution.

Did you jiggle from the cabin side or from the engine bay?

I'll report back if I solve mine.

 

[22RE3URFE]

Now my battery light is on and voltage is showing low on the cluster. Battery is reading low on the multimeter with the engine running.

Going to replace the alternator, wish me luck. 211k miles. I'm hoping these issues are somehow related but who knows.