Hey everyone, have a gs430. Lights are popping on. But are intermittent. I can drive for 5 miles, park car, come back out and lights are on. Or I can drive down the road about 5mins, and they may pop on. But I have traction control light, red exclamation, tpms and power steering light. All solid non blinking. Although, power steering is weird and it comes on and off randomly, and sometimes when I come to a stop it'll pop on and then when I accelerate, it goes off. The powersteering is not affected and have full capabilities with ps even when light is on. I see rh wheel speed sensor circuit. If that was true and it was faulty, ABS light should pop (in my experience). I did just do a valve cover gasket, and tube seal job, so wondering if there's a connection issue especially since these lights are popping on at random times or even driving until destination without them coming on. Any thoughts or suggestions would be great!

 

For complicated / electrical issues, I would go to the lexus dealer and pay for a professional diagnostic, that way you will know the exact problem and solution and decide how to proceed afterwards.

 

The C1304 and C1289 are both from your Brake control ECU and complaining about the other two codes (C1289 is that your vehicle stability control / VSC is malfunctioning, and C1304 is complaining that your power steering and brake are malfunctioning. These cars love to throw extra codes from multiple ECU just because one is confused.

C1567, that is the scary looking one, if true it is at best wiring harness damage and need repair, at worse a fried ECU. C0200 is easy to fix if it is true.
The fact you have *both* C200 and C1567 has me thinking and you are right, a faulty ABS sensor should also fire up an ABS warning light so it is odd that the brake control ECU isn't lighting it up. Note that the Gateway ECU which drives the instrument cluster and ABS light connected via CAN bus to the Skid Control ECU, so maybe wiring.

- Last time my car lit up with CAN bus failures, the battery was going bad. When you say intermittent... You said they light up when you start and go away eventually, or they light up after driving for a while and then go away? I know it sounds stupid, but the car is constantly slow trickling power for things like the fob location detection. If the light is coming and going, and you weren't in an accident or do something physically to the car. I'd suspect the battery. Electrical gremlins are immediately battery suspect, it happened twice on my GS and once on my wife's NX, in all 3 cases, new battery made random codes go away.

- The other option is physical damage to wiring harness, did you fiddle in there and damage a connector/wire, or maybe mouse/small rodent went in and chewed some wired.

Good luck. If you need locations of the ECUs/wires, I may be able to find them. The steering control ECU is in the centre console behind the shifter. The power steering control ECU is under the battery.
For the last DTC


The C200 is just a dumb sensor, it is probably not the problem, it is easy to get to just by taking the wheel off, the problem is that it is likely hard stuck in there and if you have to replace it, be ready to break the old one.

 

Sounds like you have a voltage issue, maybe alternator is it original? But I would check the voltage at the battery with the car running and when it is off

 

The EPS module under battery, one side connection was not snapped down and when I installed battery, it shifted the housing underneath and dislodged itself. All good now! But man that was lots of diagnosing lolol