I got an 2008 Lexus LS 600HL with 53k miles. Drove fine until one day i drove about 500 feet and it died, now it will start for 2 second and dies right away and will not start again until it sits for a while again. Codes show communication issue with PCM and Hybrid control module i checked wires and both modules, even programed both modules from my other LS 600hl to this car and same issue again. Had a couple very good mechanics look at it and they are also not sure what could be wrong with it, hate to have it just sit in my yard someone please help! Thanks!

 

Have you tested the "crank" battery? Sometimes batteries at the end of the service cause problems in communications with various modules.

 

I bought a brand new battery from lexus dealer just before this happened so it is brand new, also tried a hard reset by connecting both negative and positive terminals together.

 

What about the alternator, is the battery being charged?

 

Not sure because car shuts off right away but seems like it is working i don't think it would start with a bad alternator and car doesn't give any codes for it.

 

If the alternator is not providing enough power to the system, it will cause all kinds of issues including intermittent connection to the ECU. You should be able to check the voltage when the car is running. Also, double check the battery terminals.

 

What should i check for on the battery terminal? Hard to test the alternator since it shuts off within like 2 seconds after starting.

 

Sorry, I thought it was 2 minutes. Just make sure that the terminals are clean and sit properly.

 

What are the specific codes you are getting?

 

I am getting these
C1259
C1289
C1310
U0100
P0517 but the battery sensor was disconnected when these were read

 

When you say it will not start is mg1 trying to spin the engine ( turning over but not starting) ? How many bars are filled on the hybrid battery? How long has it been sitting since its last long drive. 50k miles is really low for a 2008.

MG1 is the starter and generator ( alternator) on the 600h.

 

Engine will run for a few seconds before it shuts off, but it will not start again until it sits for a while. It wasn't really sitting much i was driving it before this happened and it's been 2 months since it happened but like i said before it does start. Not sure what you mean by bars filled. Do you mean what the display shows when the car is running for the hybrid system?

 

When it starts for a couple of seconds, is the gas engine running or is it solely on battery power?

 

It starts and runs on the gas engine not on battery power.

 

Yes the display in the car will show a picture of the hybrid battery with bars indicating how much of a charge it has.

C1259 can be tripped if the service plug in the trunk for the hybrid battery has not been properly seated. If I recall correctly you need to push it in and and flip the handle. I forgot to flip the handle once. It's an easy mistake to make. Perhaps someone messed with it during your 12v battery change.