RX400H, runs, drives, warms up, dies and then limps home

[Jollyjacktarjack]

Morning Folks,

This is a separate thread from my 'RX400H O2 sensors' to try and illicit further responses from the Lexus community please?

My 2006 RX400H, starts, drives, warms up and then engine cuts out and I have to limp home on the hybrid Battery.  I have checked and cleaned the MAF and air filter, checked as far as possible the vacuum hoses and even popped out the front bank of spark plugs.  

I love driving this car but I am at a loss of what to do next, grateful for anybody who may have a clue please?

Codes are as follows - P0138 (changed 2 of these), P3190, P3193 and P0A0F.

Thanks,

JJTJ

 

[steve2006]

From previous experience and a lot of reading the favourite cause of the engine failing to start when warm or cutting out when warm as in your case (thermal) would point towards a defective crankshaft sensor.

Without this component working correctly the engine ECU has no reference to engine timing so doesn’t know which spark plug to fire and shuts down the fuel injectors.

The only sure way of accurate diagnosis is to read the live data looking at the CPS output waveform and looking for any anomalies when the engine gets warm.

Another way is to cool down the CPS with some freezer spray when the fault happens and then see if the engine starts confirming it is thermally related.

I did find this video which gives the same codes and symptoms you have and mentions the CPS as one of the possible causes, some of the reasons like the fuel filter can be eliminated as the cause as this if clogged would prevent starting also when the engine is cold, it’s heat sensitive components you need to look at more closely like the CPS.

 

[Jollyjacktarjack]

Thanks Steve, do you have any signposts towards the CPS location please? I think (from my internet scour) is that its located on the front right of the block beneath the air filter housing?

Just another thought, would I not get a fault code for a defective CPS, or are the other codes sort of masking the root cause?

Thanks,

JJTJ

[steve2006]

The sensor is located on a bracket to the right and slightly up from the crank pulley ( 1 o’clock position) it is secured with a single bolt.

2nd picture shows position albeit on a dismantled engine.

The 3 codes you have include a possible defective CPS if you look at the service and diagnostic sheets in the video.

 

[cruisermark]

This could be a very simple fix is Steve is right - Good luck - and please do let us know how you get on.

[Jollyjacktarjack]

Steve, many thanks and yes Mark, I will update all on my progress

Thanks again,

JJTJ

[Jollyjacktarjack]

Afternoon Folks

Update as promised, it didn't fix the problem unfortunately.  Replaced the CPS and the 12v Battery for good measure.  Exact same problem as earlier, other than the engine didn't run for as long and within 300 metres I was turning for home and limping back on hybrid Battery.

Same codes appeared P0138 (changed 2 of these), P3190, P3193 and P0A0F

Any other pearls of wisdom gratefully received please?

Thanks,

JJTJ

[steve2006]

Looks like you’re going to need some “live data” diagnostics performed by a decent company with Toyota experience.