2016 Prius C Headlight Malfunction light

Any updates?

 

I read the c section a lot... I haven't seen anyone else post a problem related to the new style LED lamps yet.

Subscribed to hear how it goes, wish I had something more to offer...

Good luck!

 

Do the low beam and the high beam headlights both work properly?

Looking through the Repair Manual (more info), that’s probably diagnostic trouble code (DTC) B2430, LED headlight LH malfunction, and the technician is correct—the headlight assembly LH, H-LP relay, harness or connector, and main body ECU are all listed as potential trouble areas for this code, for which the detection condition is given only as “LED headlight LH circuit malfunction.”

The Manual has an eleven-step troubleshooting procedure, but if the DTC is for only one side, and the low beam and high beam headlights are working, that rules out the H-LP relay, and the remaining steps aren’t likely to be of much use, especially if the problem is intermittent. Diagnostic advice such as “Replace the headlight assembly with a new or known good one” might be fine for a $3 lamp, but not for a module with a list price of $999.05.

Before putting more time or money into the problem, I’d suggest clearing the DTC, if the technician didn’t, and waiting to see if the message returns. That’s what I did years ago with a vaguely similar complaint from the main body ECU about a light circuit—although in my case, there wasn’t a message to go with it.

If the message does come back, I’d start by checking the pink digital signal wire, which runs from the main body ECU (LLEW, G88-24) to the headlight assembly LH (S, A67-1) via AG2-3. This check is the last step in the official procedure, but an intermittent problem with that wire would be consistent with a detectable communication failure that wouldn’t interfere with the basic functioning of the lights.

 

Recently the same problem occurred in my Prius 2016 C. It happened after I had a lead lamp replaced following a fender bender accident. A new lamp assembly was installed, all Toyota equipment. The problem started after the new headlamp was installed. The message is intermittent, not constant. My body shop guy says it is the headlamp computer causing the problem. The dealer wants to put in a new assembly for $1.3 k. No way. For now, the body shop is claiming the guarantee from the supplier of
the replacement lamp assembly needs to provide a fix. FYI, this occurred on the passenger side headlamp. All this is a work in progress. If it gets resolved I will post what happened.
In the meantime. If anyone else has info that would help, please post about it.