Engine warning light?

[Big Yellow]

Hi,

The "Engine" light on my wife's 2005 RAV4 has come on (yellow), and I guess this can mean many things...? Any ideas where to start to figure out what is wrong?

/ B Y 

[IanML]

Plug a diagnostic tool into the " OBDII" connector under the dash on the driver's side, and read the code(s).  The Toyota tool is called TechStream, runs on a Windows laptop and offers more facilities than generic tools.  Lots of offers on eBay.

This one looks good:  Link

[Grumpy stumpy]

My guess a O2 sensor fault as normally the only problems they get ? Petrol ones anyway . Like above you can buy yourself a code reader mine was around £10 off eBay and gives you a code number to look up in the book you also get and see what fault is and you can clear and reset the light . O2 sensor around £80 for a decent make I.e denso and straight replacement. Mine was a orange hand held unit no laptop required.

[Mark O]

What does it say in the manual?

[IanML]

9 hours ago, Mark O said:

What does it say in the manual?

What you'd expect.  Basically, go directly to your Toyota dealer.  It doesn't say "and open your wallet",  but.....

[Mark O]

Ian

Yes indeed. That is what it says in mine - not at all helpful. Thought it may be more explanatory in other manuals......

Independent local garages often quite helpful. If I had a similar issue, my friendly local guy would probably plug in his diagnostic and tell me what the issue is for free.

 

[Big Yellow]

OK, so I ran the diagnostic and I got the error code P0627...  According to Google this is a common issue but it's not clear what the remedy is. Any ideas? Also, in the mean time, the light has gone off and does not come on again. Maybe I should just ignore it... :-)

[IanML]

As the light has gone off, the fault condition has cleared.  With no symptoms, diagnosis is well-nigh impossible.

It may never come back.  Wait and see.

[Devon Aygo]

Looking at the code I assume the Rav is a Diesel as P0627 is a common fault code on the D4d which nearly always indicates failing/faulty Suction control Valves for which Toyota have a Technical service bulletin and a set of modified valves available PN# 04221-27012

[C3PO]

I have just had this on a 2005 Rav4 I bought yesterday. 99,000 miles on the clock but goes great. Took it back to the garage and they hooked up the analyser to it. Mechanic said put in BP or Shell fuel, and see if that fixes it. It has! Not happened since.

[yossarian247]

On 2/11/2022 at 6:21 PM, C3PO said:

I have just had this on a 2005 Rav4 I bought yesterday. 99,000 miles on the clock but goes great. Took it back to the garage and they hooked up the analyser to it. Mechanic said put in BP or Shell fuel, and see if that fixes it. It has! Not happened since.

I wouldn't count your chickens just yet, it may be an intermittent fault which will come back. Although some do recommend using 'branded' fuel over supermarket sourced fuel, if it makes any difference at all (which is debatable) it will be over many thousands of miles, not a couple of days. I fear the mechanic may have fobbed you off. 

[C3PO]

You’re right - the fault came back and I have since topped up with BP fuel and added a bottle of STP injectors cleaner (the once every 3,000 miles version) into the tank and taken it for a quick blast on the motorway at 3,500 revs. Light still on when I parked but will watch what happens over the next week or so. If still there, will take it back to the garage as they said they would sort it.

[yossarian247]

7 minutes ago, C3PO said:

You’re right - the fault came back and I have since topped up with BP fuel and added a bottle of STP injectors cleaner (the once every 3,000 miles version) into the tank and taken it for a quick blast on the motorway at 3,500 revs. Light still on when I parked but will watch what happens over the next week or so. If still there, will take it back to the garage as they said they would sort it.

Sorry to hear that. Injector cleaner is worth a try certainly. What can sometimes happen is that the oxygen sensor, or the cat itself, can be slightly borderline and just trigger a fault code occasionally. My son in law's Aygo used to do it about every 6 months or so but run completely normally the rest of the time.

[C3PO]

Yes, light was out after a reset for around 30 miles, then came back on again. Bought an engine code reader and here is the result:

 

[Big_D]

I've had a similar coded on the wife's Ford many years ago, I changed the O2 sensor on the exhaust manifold and this solved the problem. I copied his from Google, which may help.

All P042X codes (where "X" can be any number) refer to the catalytic converter and exhaust system. P0420 refers to the catalytic converter or - more specifically - the oxygen (O2) sensors before and after it on the bank 1 side of the exhaust system.

 

This is where it came from: 

https://parts.olathetoyota.com/p0420-code-toyota#:~:text='Catalyst System Efficiency Below Threshold' - P0420 Code - Toyota,-Error code P0420&text=P0420 refers to the catalytic,side of the exhaust system.

[Grumpy stumpy]

O2 sensor my guess too, only thing which goes wrong with these, bullet proof . @ £85 for denso one straight swap just unplug and unscrew and refit and plug-in, can then take a couple of days to settle down until ECU sorts itself out. Just need to find which one it is as it has four.