Check Hybrid System/P Lock Malfunction when parking

corkboi · June 30, 2021

Hi Folks

I just recently bought a 2013 Lexus CT200h. I went to start the car yesterday and got The ‘P lock malfunction’ warning followed by ‘Check Hybrid System’.

The car actually started and drove fine. I disconnected the 12v Battery to clear the codes and everything seems to be ok since.

After doing a bit of reading online some people have mentioned that when the 12v Battery is on its way out you can get these Warning lights.

Can anyone throw some light on this? The Battery as far as I can tell is the original so it’s close to 8 years old. Main dealer here in Ireland is looking to charge 140e to run a diagnostic check! Thanks lads!

Herbie · June 30, 2021

Go to a shop that sells car batteries, even Halfords if you have to, and ask them to do a load test on the Battery for you, which they will usually do free or maybe just a couple of quid.

1 hour ago, corkboi said:

I disconnected the 12v battery to clear the codes and everything seems to be ok since.

Did you actually read the codes first or just clear them?

Ideally, a laptop with Techstream is the best way of reading OBD2 fault codes but if that's not possible a generic code reader may help

GS300h2014 · June 30, 2021

If the Battery is in the boot it's likely to be an AGM type. Rather than spending 140 euros on the dealer, I would suggest you use a multi-meter to check the Battery charge as and when the problem re-occurs. These hybrids only recharge the Battery at circa 5A so it does take a fair bit of time driving to re-charge the Battery.

corkboi · June 30, 2021

I just took note of the warning messages that came up on the dash. I read something online about the 12v Battery going bad being the cause of the ‘P Lock Malfunction’ message.

I then disconnected the 12v Battery in order to clear the ECU memory which it did. Car seems to be running fine but I’m trying to get to the root cause of it, just in case it might be something more serious!

Just tested the voltage with a multimeter and it read 12.55, with no load

Herbie · June 30, 2021

1 hour ago, corkboi said:

Just tested the voltage with a multimeter and it read 12.55, with no load

If you load it up that voltage may drop like a stone, which is why you really need to load test a Battery.

In the old days you could just turn on high beam lights, heated back screen, heated seats and loads of other stuff without turning on the ignition but these cars need to be in READY mode for most of these things to work, which is no good at all. As soon as the car is in READY, the 12V systems are being run from the DC/DC converter via the traction Battery.

corkboi · June 30, 2021

Okay I’ll try load testing it and see what happens. Thanks for your help lads, greatly appreciated! 👍🏻

200h · July 6, 2021

when ive had a flat Battery years ago the car would tell you to

put the car into P ( Park) even though it was in P

corkboi · July 6, 2021

Thanks 200h. I think that the Battery is probably on its way out so I’m gonna replace it ASAP. It’s 8 years old as far as I can tell. Thought it might have been something more serious, but from what I gather the 12v Battery can cause lots of weird warning messages

stormchaser · July 6, 2021

Mine packed up after 8 years.It was the original one so i replaced it with exactly the same one.

diabolik · July 6, 2021

I thought that the batteries are supposed to last 15 years but mileage can affect that as well as the time and frequency the car was stationed over the years..

How's the mileage @Storm Chaser @corkboi?

Herbie · July 6, 2021

5 minutes ago, diabolik said:

I thought that the batteries are supposed to last 15 years but mileage can affect that as well as the time and frequency the car was stationed over the years..

The high voltage traction Battery will last 15 years but the normal 12V Battery won't.

stormchaser · July 7, 2021

1 hour ago, diabolik said:

I thought that the batteries are supposed to last 15 years but mileage can affect that as well as the time and frequency the car was stationed over the years..

How's the mileage @Storm Chaser @corkboi?

I,m on 111K now and all is well still.

corkboi · July 7, 2021

@diabolik I’m only on 37k miles.

Another question for guys here - does the mark 3 Prius use the same 12v Battery as the CT? Quotes from Toyota are much cheaper than Lexus for the same Battery, as you’d expect 😅

ColinBarber · July 7, 2021

33 minutes ago, corkboi said:

Another question for guys here - does the mark 3 Prius use the same 12v battery as the CT?

The CT is more related to the Auris than the Prius but in the case of the Battery then I think the Auris, Prius, Yaris and CT all use the same, although worth double checking as they do change parts over the years.

This is probably the cheapest you will find one from a Lexus dealer:

https://lexuspartsdirect.co.uk/parts/lexus-ct/lexus-ct-2010-onwards/lexus-ct-engine-service-kits/lexus-ct-phase-1-12v-starter-battery/