Electrical Gremlin Causing Error Light Christmas Tree?

[Alpentalic]

This started in another thread as what I thought was a P0704 neutral position sensor error. But after replacing that sensor and driving normally for a day with no errors, the truck is back in limp mode and freaking out.

I’ve got an error message for every electrical system I can imagine- TPMS, land departure, headlights, pre-collision system, traction control, etc.

The rear camera is displayed on the center console as well which is what originally led me to the neutral position sensor.

WTF is going on!? Could this be a voltage issue from a bad alternator?

 

[Alpentalic]

I ran a couple of battery/alternator checks and the battery is at 12.5V off, 14.0v at a fast idle and 13.8v idling with AC and headlights on. A load tester shows the battery in the low end of the”good”…

 

[Sandroad]

In your other thread, I suggested looking carefully for water corrosion damage because I didn’t believe it was the coffee. With this new info, that’s even more important to do. Remove the door sills and take apart the electrical connectors to look for corroded pins.

See post 17 in this thread for the procedure

Post in thread 'Water in footwell of lc 200'

Jul 6, 2025

Any update? I have a similar problem now except on top of my driver side floor being wet, and now a short somewhere causing the drivers door sensor to fail, my A-pillar is also soaked...

You need to pull the door sill trim and inspect for water pooling. Most likely the connectors there by the footwell will have corrosion. Dry the area soon and inspect and address the corrosion.

• bloc

• 

And here is one of several threads on the issue

Thread 'Water leak intrusion in door causing CEL, VSC, and flashing 4LO?'

Jul 29, 2023

2008 LC200 w/ 165k on it, bought in January and have had the CEL, VSC, and flashing 4LO lights several times now. I've begun to notice that it is just after a heavy rain and the truck is stationary - it does not occur if I drive through rain or wash the car. The codes I got were:

P2446
C1201
C1268
B1421
B1424

I've checked all the usual suspects for water intrusion but can't find any actual source, though the large plugs for the body harness at the base of both of my doors had some corrosion in them, I cleaned those but still had all the previously referenced lights come back once...

• ApexRex
• 4lo door leak vsc water leak
• Replies: 13
• Forum: 200-Series Cruisers

 

[Alpentalic]

In your other thread, I suggested looking carefully for water corrosion damage because I didn’t believe it was the coffee. With this new info, that’s even more important to do. Remove the door sills and take apart the electrical connectors to look for corroded pins.

See post 17 in this thread for the procedure

Post in thread 'Water in footwell of lc 200'

Jul 6, 2025

Any update? I have a similar problem now except on top of my driver side floor being wet, and now a short somewhere causing the drivers door sensor to fail, my A-pillar is also soaked...

You need to pull the door sill trim and inspect for water pooling. Most likely the connectors there by the footwell will have corrosion. Dry the area soon and inspect and address the corrosion.

• bloc

• 

And here is one of several threads on the issue

Thread 'Water leak intrusion in door causing CEL, VSC, and flashing 4LO?'

Jul 29, 2023

2008 LC200 w/ 165k on it, bought in January and have had the CEL, VSC, and flashing 4LO lights several times now. I've begun to notice that it is just after a heavy rain and the truck is stationary - it does not occur if I drive through rain or wash the car. The codes I got were:

P2446
C1201
C1268
B1421
B1424

I've checked all the usual suspects for water intrusion but can't find any actual source, though the large plugs for the body harness at the base of both of my doors had some corrosion in them, I cleaned those but still had all the previously referenced lights come back once...

• ApexRex
• 4lo door leak vsc water leak
• Replies: 13
• Forum: 200-Series Cruisers

Thanks for the links here- those are helpful. I’ll do a little digging for water intrusion in those areas. I had a windshield replaced at one point but it has been almost two years without issue.

My other idea is corrosion on battery/accessory terminals causing contact issues. It’s a low bar to remove and clean those so I’ll try that next…

 

[bloc]

I’d check for water even if the terminals show evidence of poor contact. This issue can get you into real trouble if not addressed promptly.

 

[Alpentalic]

Cross posting here in case anyone comes across it:

per a local indy Toyota specialist- they traced the short to the switch center between the cup holder and the shifter. The switches were sticky admittedly but i thought they’d been working okay. Sounds like liquid worked its way down into one/multiple switches and into the cluster of electronics under those switches which was causing intermittent shorts.

I’m replacing the switches (which only come as a single unit unfortunately) and I’m really hopeful this is a permanent fix. I’m still surprised this could cause such a significant (and intermittent) short but they said they ran through the diagram on that circuit and this was the only faulty element they found.


Switch Assembly

 

[Sandroad]

I think you might be the first owner on Mud to replace that switch assembly. Looking at the cost, that was a pricey cup of coffee!