Rav 4 Problems

[jas-E]

Hey,

I have just bought a Rav 4 for my mother to drive around in as she needed a reliable efficient car. I've owned lots of Toyotas and currently have two Landcruisers which have never let me down! Picked up the car on Monday, and everything seemed fine for a 2001 car. Its a 4.2 2.0L D4D Rav 4 with 86000miles on the clock.

Problems started as soon as i hit the motorway. Once over 50mph, it blew a fuse which took the speedo, A/C, Fans and passenger and rear electric windows with it. Found the blown fuse under the steering (the 10A that says Gauge). Replaced it and as soon as i hit 50mph it blew again. I checked the engine bay and the two earth points on the inside of the wings had some corrosion on them. So cleaned and greased them up and the Battery neg had some corrosion on it too. Sorted that out aswell. It still kept blowing the fuse. Tried a 15Amp fues and even that blew.

Decided to get it checked so booked it in for Monday. But went to get some stuff yesterday night, and left the key in the ignition on and the radio light and clock were on (radio was turned off), and when i got back it wouldnt start as the Battery had died!!! Had a look and it was defo an after market Battery which is rated at 60Amps. Thats the same size as my mums older honda civic 1.3. I'd imagine being a diesel itwould need a bigger one? Anyway jump started it with my cruiser and it started. Drove it home and just as i got home all the gauges died, the front lights went dim and once i turned it off it wouldnt turn over again!!

Any ideas as to where i can start looking to diagnose the problem please. Im fairly handy with tools, but havent worked with d4d engines or a newer toyota yet so some guidance would be good..

Thanks for your help and apologies for such a long first post

Jas

[halfpastsix]

Sounds to me like the alternator is toast. I bought a bike a few years ago that had no generator! I couldn't tell at the time because the owner had charged the Battery and it was a kick start, but over the course of a week things stopped working. Check the Battery voltage when it is charging. It should be around 12v when the engine is not running, and between 13.5 and 14v with the engine running but with nothing electrical switched on. Also rev the engine and check to see if the voltage spikes above these. If the regulator is playing up the voltage could peak to around 70-80 volts. This can blow fuses of anything that happens to be on at the time.

If it was from a dealer, take it back. If it was a private sale, oops!

[jas-E]

Sounds to me like the alternator is toast.

If it was from a dealer, take it back. If it was a private sale, oops!

Hey,

Thanks for your reply. I'll check the car tomorrow evening when i back from work. Is there a particular reason that it would blow on the one fuse..?would have thought if it spiked to 60-70 volts it would have taken a handful of fuses?

Unfortunately it was a private sale so can't take it back. He willbe hearing my two cents worth in the evening though!

Thanks again

Jas

[jas-E]

Check the battery voltage when it is charging. It should be around 12v when the engine is not running, and between 13.5 and 14v with the engine running but with nothing electrical switched on. Also rev the engine and check to see if the voltage spikes above these. If the regulator is playing up the voltage could peak to around 70-80 volts. This can blow fuses of anything that happens to be on at the time.

Hey mate,

I fitted a new Battery to the RAV and checked the voltage with the car at idle. It was about 12.8Volts. I was expecting 14v aswell like my other car but this stayed at 12.8V. I took the car for a drive for a couple of miles and checked the voltage and it was just hovering aroung 12.8V.

If the alternator was playing up then wouldnt the Battery voltage have dropped after driving around?

Thanks

[anchorman]

No because you are measuring "terminal" or "residual" voltage. With the voltmeter connected to the Battery just rev the engine up to about 1500 rpm and see if it now climbs to the expected value.

Because this is speed related it might be to do with the speed sensor on the gearbox. They are known to play up and the wire can chafe through on the gearbox. Just disconnect it (down at the back of the box) and then run it again to see if the fuse blows. If it doesn't you could try some WD40 and reconnect it but just follow those wires back along the gearbox and make sure they haven't rubbed through the insulation somewhere.

[jas-E]

No because you are measuring "terminal" or "residual" voltage. With the voltmeter connected to the battery just rev the engine up to about 1500 rpm and see if it now climbs to the expected value.

Because this is speed related it might be to do with the speed sensor on the gearbox. They are known to play up and the wire can chafe through on the gearbox. Just disconnect it (down at the back of the box) and then run it again to see if the fuse blows. If it doesn't you could try some WD40 and reconnect it but just follow those wires back along the gearbox and make sure they haven't rubbed through the insulation somewhere.

Hey Anchorman,

Thanks for your reply. I did check the voltage across the Battery with the engine revving upto 2000revs, and it was still showing about 12.8V.

I did a search on the forum earlier when i got the car, and saw the posts about the sensor on the gearbox. I did remove it and sprayed it with WD40, but the problem was still there. Im actually not quite sure whether i cleaned up the right plug as it was really difficult to see (must have cleaned up the reverse light switch!) Is it the one that you can just about see from the passenger sidewheel arch sorta pointing upwards?

Thanks

Jas

[anchorman]

You can see it on page one here;

g_box.pdf

Going back to the Battery voltage, just try something else.

Attach the voltmeter while the engine is switched off and note the reading with the headlights switched on for about one minute - not more. With the lights still on start it up and note the voltage again. I just want to understand if it is charging and need to see the variation. It could be that the regulator is faulty and I wonder if it isn't charging and then as halfpastsix suggests there is an unregulated charge severe enough to blow a fuse. If that is the case it shouldn't be anything to do with road speed but engine speed. To back this theory up you need to keep that voltmeter connected and increase the revs still further. Try easing it up to about 3000 rpm but don't hold it up there for too long.

I'm off to work soon but will look in tomorrow.

[jas-E]

You can see it on page one here;

g_box.pdf

Going back to the battery voltage, just try something else.

Attach the voltmeter while the engine is switched off and note the reading with the headlights switched on for about one minute - not more. With the lights still on start it up and note the voltage again. I just want to understand if it is charging and need to see the variation. It could be that the regulator is faulty and I wonder if it isn't charging and then as halfpastsix suggests there is an unregulated charge severe enough to blow a fuse. If that is the case it shouldn't be anything to do with road speed but engine speed. To back this theory up you need to keep that voltmeter connected and increase the revs still further. Try easing it up to about 3000 rpm but don't hold it up there for too long.

I'm off to work soon but will look in tomorrow.

Thanks Anchorman,

I'm away from the car till thursday, but i'll get someone to do what you asked and egt you the results.

Thanks again

Jas

[boilerman]

Is that the one I pull off if I don't want anymore miles on my clock ????????????

[halfpastsix]

I suspect now that the regulator has just plain broken. Your voltage is now way too low for a running engine. It should be around 12 volts when not running and 14ish when running. Either that, or there's a loose wire somewhere. Either way, you're not charging the Battery and it will eventually go flat. I doubt you've used it enough since fitting a new Battery for it to have gone flat on it's own, but I wouldn't plan any long drives in the dark until it's fixed.

[anchorman]

Is that the one I pull off if I don't want anymore miles on my clock ????????????

Yep. It's also the one you pull off if you don't want a speedo and to put it into limp mode and completely disable the VSC if you have it!!!

Probably best to leave it on!!!

[tspirit888]

Hey,

I have just bought a Rav 4 for my mother to drive around in as she needed a reliable efficient car. I've owned lots of Toyotas and currently have two Landcruisers which have never let me down! Picked up the car on Monday, and everything seemed fine for a 2001 car. Its a 4.2 2.0L D4D Rav 4 with 86000miles on the clock.

Problems started as soon as i hit the motorway. Once over 50mph, it blew a fuse which took the speedo, A/C, Fans and passenger and rear electric windows with it. Found the blown fuse under the steering (the 10A that says Gauge). Replaced it and as soon as i hit 50mph it blew again. I checked the engine bay and the two earth points on the inside of the wings had some corrosion on them. So cleaned and greased them up and the battery neg had some corrosion on it too. Sorted that out aswell. It still kept blowing the fuse. Tried a 15Amp fues and even that blew.

Decided to get it checked so booked it in for Monday. But went to get some stuff yesterday night, and left the key in the ignition on and the radio light and clock were on (radio was turned off), and when i got back it wouldnt start as the battery had died!!! Had a look and it was defo an after market battery which is rated at 60Amps. Thats the same size as my mums older honda civic 1.3. I'd imagine being a diesel itwould need a bigger one? Anyway jump started it with my cruiser and it started. Drove it home and just as i got home all the gauges died, the front lights went dim and once i turned it off it wouldnt turn over again!!

Any ideas as to where i can start looking to diagnose the problem please. Im fairly handy with tools, but havent worked with d4d engines or a newer toyota yet so some guidance would be good..

Thanks for your help and apologies for such a long first post

Jas

ive heard of a very similar problem,,it was a water leak where the rear washer hose comes through the bulkhead and the water drips on to the multi plugs ay the kick panel to bulkhead area when you seperate the multiplugs there will be lots of corrosion in the plug causing a short circuit or poor connection

[jas-E]

You can see it on page one here;

g_box.pdf

Attach the voltmeter while the engine is switched off and note the reading with the headlights switched on for about one minute - not more. With the lights still on start it up and note the voltage again. I just want to understand if it is charging and need to see the variation. It could be that the regulator is faulty and I wonder if it isn't charging and then as halfpastsix suggests there is an unregulated charge severe enough to blow a fuse. If that is the case it shouldn't be anything to do with road speed but engine speed. To back this theory up you need to keep that voltmeter connected and increase the revs still further. Try easing it up to about 3000 rpm but don't hold it up there for too long.

Hey mate,

I tried what you asked me to do and seems like the alternator is not charging. These are the voltages from the battery:

-Voltage as standing checked yesterday night - 12.44V

-Voltage with lights left on for 1 minute - 12.06V

-Voltage with lights and engine ON at idle - 11.72V

-Voltage with lights and engine ON running at 2500rpm - 11.92V

-Voltage with lights and engine ON running at 3000rpm briefly - 11.9V

Would expect that to be 14V atleast at 3000rpm. I'll get another alternator and replace it as im going to change the timing belt on it so best time to try another one. Is it easier to do a continuity check on the wires from the alternator to the Battery?

tspirit - i read about water getting to the kick panel when i searched the forum and have checked all the plugs and they seem fine. Thanks

halfpastsix - any idea on the wiring path from the alternator to the Battery so i can have a closer look at the wires? I had a quick look onsunday as it was getting dark and was struggling to see the alternator as its behind the engine in these cars..!

I found someone with a diagnostic tool so should be able to figure out why the fuse keeps tripping. Will that also pick a fault with the alternator?

Thanks for all your replies guys.

Jas

[anchorman]

Definitely not charging so as long as all the wires are intact the alternator is the obvious starting place. The checks were done with the the fuse reinstated, right? It won't charge with that blown.

You can use a simple continuity tester to check between the main alternator output, starter main wire and Battery pos'. The ign light should come on when you turn the key as that light provides the field to the alternator.

A multimeter will do enough checks to test the charging system but if you are talking about the OBD tool for diagnostic testing the 2001 diesel doesn't support it.

Was the vehicle standing for a long time before you bought it? If so the brushes can stick and if you are reasonably competent you can take them out and free them. If they are worn you can always get some brushes from a washing machine shop and just file them to suite and pop them in the holder. For side mounted brushes I use fuse wire looped around the end to feed the brush gear over the comm' and then just pull the wire carefully out. End mounted brushes are no problem;

alt.pdf

brushes.pdf

charge.pdf

It still doesn't answer why it only does it over 50mph unless that was red herring. Does it still do that?

To help with your timing belt here is some more info;

timing_1.pdf

timing_2.pdf

timing_3.pdf

timing_4.pdf

ps_belt.pdf

[jas-E]

The checks were done with the the fuse reinstated, right? It won't charge with that blown.

Hey Anchorman,

I had done all those checks with the fuse blown! I have just fitted a new fuse and did all those checks, and the Battery is showing 14.2V with the car on idle. Turned the engine off and turned the lights on and the voltage dropped from 12.4V to 12V - started the engine and went back up to 14.2V. So the alternator is working.. Cheers for that - almost paid for a new one which wouldnt have solved anything!!

The fuse that keeps blowing is the 'Gauge 10A' fuse in the fusebox behind the pocket next to the bonnet opening lever. When blown, it takes the A/C, internal fan, speedometer, sunroof and all the electric windows EXCEPT the drivers window. To get to the bottom of the fault is it just a matter of disconnecting each of those plugs and taking the car for a drive to see what is causing the fault?

A multimeter will do enough checks to test the charging system but if you are talking about the OBD tool for diagnostic testing the 2001 diesel doesn't support it.

The guy with the diagnostic tool says he can plug it into the car and check for fault codes and sounded quite certain that he could do it. Should i just tell him not to bother as he is charging me for it!

Thanks for all the help and info you have sent me regarding the timing belt mate. Really appreciate it.

Jas

[anchorman]

It is this 50mph thing that is confusing.

In answer to your question, the normal way to diagnose a fuse blowing issue is to disconnect everything that it supplies and then see which one is going to earth by continuity. Not that easy when it only does it at 50mph!!! In this case it is easier to disconnect all items and reconnect things until you can drive over 50mph without it blowing.

Did you try the charging right up to 3000rpm to see if it is a regulator fault?

Are you sure it still blows fuses above 50mph?

Did you try it with the speed sensor disconnected to see if it still blows?

With regard to the tester, some of these garages have these sophisticated hand held Sun or Snap-On anylisers (or similar) with a Toyota module. If your RAV has the OBD socket by the bonnet pull it might read some things but only very basic 2 digit codes. The newer 4.2s (with the round spotlights) offer 4 digit codes and then the later 4.3s will provide 1000's of codes. I think I would ask your man if there is a charge if he cannot read it as you don't think it will but if he says it can and it does then it is worth it!!!

If he charges you £30 for telling you it won't read he is a complete @rse.

Off to work again soon but will look in later.

[jas-E]

It is this 50mph thing that is confusing.

In answer to your question, the normal way to diagnose a fuse blowing issue is to disconnect everything that it supplies and then see which one is going to earth by continuity. Not that easy when it only does it at 50mph!!! In this case it is easier to disconnect all items and reconnect things until you can drive over 50mph without it blowing.

Did you try the charging right up to 3000rpm to see if it is a regulator fault?

Are you sure it still blows fuses above 50mph?

Did you try it with the speed sensor disconnected to see if it still blows?

Hey mate,

OK the Battery voltage with a fuse fitted at idle is 14.02V, at 2000rpm is 14.05V and at 3000rpm is 14.06V.

Battery voltage with A/C turned on (as this is linked to the same fuse) is 13.92V at idle, 13.94V at 2000rpm and 3000rpm. It did not blow the fuse.

Ran the engine at 2000rpm and opened and closed all windows and everything worked fine without blowing the fuse.

Once the A/C turned off the voltage came up to 13.98V at idle.

I havent tried disconnecting the speed sensor and checking that as i have been asking my sister to do all these tests over the phone. She will not be able to get to the speed sensor though. So i can check that on thursday evening. Can it be the speed sensor itself thats grounding out?

Thanks

Jas

[anchorman]

Well we're speculating a bit here but I can't see why it goes to ground at 50 ish. I will have a study at the wiring diagram when I get chance.

The main thing is to try disconnecting it when you can get at it in case we are barking up the wrong tree.

[jas-E]

Well we're speculating a bit here but I can't see why it goes to ground at 50 ish. I will have a study at the wiring diagram when I get chance.

The main thing is to try disconnecting it when you can get at it in case we are barking up the wrong tree.

If the speed sensor is knackered and groundingout, that could be the reason the fuse blows past a certain speed can't it?

I'm guessing the speed sensor is just a variable resistor so as the speed increases the resistance reduces and that controls the speedo. If that is the fault in the system then i should be able to disconnect it and drive around and all else should work fine right?

cheers

Jas

[anchorman]

Err no Jas

The speed sensor is a little voltage generator consisting of a ring of magnetic teeth which travel past a pick-up a bit like an abs sensor and pole wheel. The signals are converted to drive a little stepper motor which turns the needle on the dash. All that happens is the faster the car goes the more voltage is applied and the higher the needle goes. They work going backwards too!

I guess it isn't impossible to get a fault in the sensor but it seems strange that it is OK generating voltage then all of a sudden earths. However, it can't be taken out of the equation just yet and in some ways it would be the easiest thing to fix so lets just keep our fingers crossed that disconnecting it stops the fuse blowing. On a 4.3 you wouldn't get away with disconnecting it (apart from the fact the speed is measured at all 4 wheels and not on the gearbox) the signal is used for the VSC and engine management and it would definitely spit its dummy out and drop into limp mode. On a 4.2 you might get away with it but if the ecu is hooked up (and I haven't had chance to check yet but will!!!) it might cause some other strange problems.

[jas-E]

Thanks for that explanation about speed sensors. I'll try running the car without that sensor first thing on friday morning and see if it causes the fuse to blow.

The first time the fuse blew, the engine light turned on. I didnt notice any other issues with it running. When i turned the car off and restarted it the engine light went off.

[shcm]

Err no Jas

The speed sensor is a little voltage generator consisting of a ring of magnetic teeth which travel..........................

Yep, but just to avoid any confusion, most (if not all) speed sensors produce a waveform, the frequency of which is proportional to the speed of the thing it is measuring. Most these day just produce a square wave output with a variable frequency.

Attachments have not always worked for me in the past, but have a look at page 7 of the attached.

h36.pdf

but if the ecu is hooked up (and I haven't had chance to check yet but will!!!) it might cause some other strange problems.

Certainly for the 4.2 2003 on, it would appear to be. I can't think of any EMS design I've worked on that didn't have vehicle speed input, but I think some of the fairly basic early examples didn't. Might still run without it though.

Yep, on the 2003 diagram, the speed sensor supply is shown fed off the 10A gauge fuse.

The MRE sensor diagram in the attachment shows an output transistor, but the diagram is probably simplified. Maybe a shorted collector resistor would mean the transistor attempting to pull the supply to ground, but I'd expect the transistor to pop rather than the fuse. Anyway you probably start to lose supply to the rest of the sensor circuit as the tranny attempted to pull the supply down and then it might just sit there in some odd state. Without understanding the internals of the sensor, I wouldn't like to speculate further.

I'd still be looking for a simple harness or connector short. Maybe vibration induced? Possibly 50mph is a red herring?

I bet somebody at the opposite end of the industry to me has seen loads and knows exactly what causes it ;).

Cheers

[anchorman]

Err no Jas

The speed sensor is a little voltage generator consisting of a ring of magnetic teeth which travel..........................

Yep, but just to avoid any confusion, most (if not all) speed sensors produce a waveform, the frequency of which is proportional to the speed of the thing it is measuring. Most these day just produce a square wave output with a variable frequency.

Attachments have not always worked for me in the past, but have a look at page 7 of the attached.

h36.pdf

but if the ecu is hooked up (and I haven't had chance to check yet but will!!!) it might cause some other strange problems.

Certainly for the 4.2 2003 on, it would appear to be. I can't think of any EMS design I've worked on that didn't have vehicle speed input, but I think some of the fairly basic early examples didn't. Might still run without it though.

Yep, on the 2003 diagram, the speed sensor supply is shown fed off the 10A gauge fuse.

The MRE sensor diagram in the attachment shows an output transistor, but the diagram is probably simplified. Maybe a shorted collector resistor would mean the transistor attempting to pull the supply to ground, but I'd expect the transistor to pop rather than the fuse. Anyway you probably start to lose supply to the rest of the sensor circuit as the tranny attempted to pull the supply down and then it might just sit there in some odd state. Without understanding the internals of the sensor, I wouldn't like to speculate further.

I'd still be looking for a simple harness or connector short. Maybe vibration induced? Possibly 50mph is a red herring?

I bet somebody at the opposite end of the industry to me has seen loads and knows exactly what causes it ;).

Cheers

I've been willing you to look in!!!

It will be interesting to see what happens with it disconnected. Nowthen my tax is due, if I will you to pay for it................. :P

[shcm]

I've been willing you to look in!!!

It will be interesting to see what happens with it disconnected. Nowthen my tax is due, if I will you to pay for it................. :P

Spooky, I don't go in the post office that often but went in there yesterday.

Now, with respect to this tax, does your ESP work the opposite way around? How many fingers am I holding up???? (:P to you back!)

[anchorman]

Four!!!!

.........on two hands