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Discussion Starter #1 (Edited)
ABS, SLIP, BRAKE and No Brake Lights / No Cruise

SOLUTION: BAD STOP LIGHT CONTROL RELAY ASSEMBLY BEHIND GLOVE BOX (Connection A43 on 2009+ Models)

See Here---> http://www.rav4world.com/forums/98-4-3-interior/131914-abs-vsc-brake-no-brake-lights-no-cruise-2.html#post1315210
See Here---> http://www.rav4world.com/forums/98-4-3-interior/131914-abs-vsc-brake-no-brake-lights-no-cruise-3.html#post1315274
Buy Here---> http://chkkty.en.alibaba.com/product/1360301797-218440067/Automotive_parts_12V_30A_fan_relay_895A1_46020_for_toyota.html

My wife's 2010 V6 AWD Rav4 is throwing the following warning lights: ABS, SLIP, and BRAKE

In addition to these lights the brake lights are not working nor is the cruise control working.

I have pulled the brake pedal switch and checked for continuity and it passed per the below:



Due to the fact the the brake lights are not working I am unable to reset the ABS codes by compressing the brake pedal 8 times within 5 secs while the OBD diagnostic port pins 4 and 13 are jumped to each other.

I am unsure at this point if the trouble codes are being thrown because of a wheel speed sensor, brake light circuit issue, if one is a symptom of the other, or a combo of the two.

Thoughts?
 

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First step is fixing the brake lights.
Is there 12v power at the switch?
 

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Discussion Starter #3 (Edited)
First step is fixing the brake lights.
Is there 12v power at the switch?
Will check Voltage at Pin #2


Have checked fuses 1 (TAIL) and 9 (STOP) inside the car and both show continuity.


Thoughts?

Edit:
I have also checked the brake relay in driver side relay box and it appears to be functioning properly. I also swapped it with fuel pump relay to double check. Not sure if it should work in this fashion, but when the Key is in Position II the brake relay is not clicking? What should cause the brake relay to energize?
 

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With the key in II position, there is not voltage on car side pigtail.
What should cause the brake relay to energize?
The brake pedal switch receives voltage through the 10A STOP fuse. This fuse is hot all the time (even with the key removed).

The pedal switch receives this voltage on the White wire of the connector (Pin #2). When the pedal is pressed, the voltage leaves the switch on the Light Blue wire (Pin #1) and continues to the brake relay.

The voltage enters the relay on Pin #4 and leaves on a normally closed contact via Pin #3, which is connected to the rear brake lamps . In other words the voltage passes right through the de-energized relay and on to the rear brake lamps.

The only time the brake relay operates is when the Skid Control ECU energizes the relay to operate the brake lights during moments that VSC takes over control of the vehicle.
 

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I much prefer checking 12V circuits with a cheap 12V (filament type) test light. It'll verify that power is or isn't getting where it's supposed to. Beats "the fuse looks good" or the "switch checked continuity" by drawing current thru them. Quick & accurate way to find out where the voltage stops. :thumbs_up:
 

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If codes properly check usually it's a stop light switch is the problem but sometimes it's the fuse or the brake relay. I do have same problem but able to solve by checking the proper codes and checking it step by step.
 

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Discussion Starter #7
The brake pedal switch receives voltage through the 10A STOP fuse. This fuse is hot all the time (even with the key removed).

The pedal switch receives this voltage on the White wire of the connector (Pin #2). When the pedal is pressed, the voltage leaves the switch on the Light Blue wire (Pin #1) and continues to the brake relay.

The voltage enters the relay on Pin #4 and leaves on a normally closed contact via Pin #3, which is connected to the rear brake lamps . In other words the voltage passes right through the de-energized relay and on to the rear brake lamps.

The only time the brake relay operates is when the Skid Control ECU energizes the relay to operate the brake lights during moments that VSC takes over control of the vehicle.
Re-checked,

At the switch I'm getting 12v at Pin #2 (white) on the car side.

When I jumper Pin #2 (white) to #1 (blue) there is no voltage at Pin #4 at the relay.

 

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At the switch I'm getting 12v at Pin #2 (white) on the car side.

When I jumper Pin #2 (white) to #1 (blue) there is no voltage at Pin #4 at the relay.
The 10A STOP fuse also feeds pin#5 or the relay. Please check that pin# 5 has voltage. When the VSC kicks in (or the cruise control applies the brakes), the relay sends this voltage out on pin# 3 to light the brake lamps. You can jumper relay pin#5 to pin #3 (with the relay removed of course) and your brake lights should come on. I'm almost certain this will work, but the test will help us eliminate a few things.

When you step on the pedal, the voltage leaving on pin# 2 (blue wire at the pedal switch) is also used to release the shifter lock. Does your shifter lock work like normal when you step on the brake?

The voltage leaving on pin#2 also feeds the ECU, so that it knows when you are stepping on the brake. Since you have the other dash lights warning of a brake problem, I suspect this voltage is not arriving at the ECU.

All these connections of the blue wire to Pin#4 of the relay, the shift interlock, and the signal to the ECU are made in one connector. It is called A35 and it is located above the pedal. It's location can be seen on page 56 of the electrical diagrams. You should test for continuity of the blue wire from the pedal switch to here, and from here to the relay socket.
 

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Jumpering pins 1 & 2 of the stop light switch is the same as pushing the pedal to operate it and according to my schematic (wish I could figure out how to post it) the only thing between pin 1 of the switch and pin 4 of the relay is a junction connector labeled A35 with pins 3 & 9, both blue wires, as the passthru. Anyone messing around under the dash that could've disconnected it?
Also, there should be live power on 5 of the relay and jumpering it to pin 3 with or w/o the relay should light the brake lights. (Be careful not to put power in relay pin 1, it comes from the Skid Control ECU.)

What's interesting is I don't see any connection to the Skid Control ECU that would facilitate resetting it's codes with the 8 taps on the brake pedal. But it does work. I've done it many times.

Okay, as he usually does Rick beat me to posting this info. But I did it in less words. :thumbs_up:

Rick, where did you see the shift lock connection?
 

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Anyone messing around under the dash that could've disconnected it?

(Be careful not to put power in relay pin 1, it comes from the Skid Control ECU.)

What's interesting is I don't see any connection to the Skid Control ECU that would facilitate resetting it's codes with the 8 taps on the brake pedal.

Rick, where did you see the shift lock connection?
Perhaps the OP originally had a defective pedal switch, but may have dislodged the A35 connector while working under the dash.

And I also meant to warn the OP about applying voltage to pin#1 of the relay socket.

The voltage from the pedal switch is sent to the STP terminal of the ECU from pin#8 of the A35 connector.I think the 8 pedal taps is interpreted as a reset command within the ECU.

The connection to the shift interlock is shown on page 210 of the electrical manual. In this case they show pin#11 of A35 feeding the STP terminal on the Shift Lock Control ECU.

So A35 is the center of everything.
 

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Discussion Starter #11
I do have 12v at pin #5 and the brake lights turn on when jumped to pin #3.

I will look for A35 as well as inspect the shifter lock function after work and advise per Rickl's advice. How do you advise testing for continuity between A35 and Pin #4 at the relay socket?

While jumping pin 5 at the relay, in ignorance, I applied 12v to pin 1 prior to your warning. I hope that I didn't blow anything. A fan? did pop on when pin #1 was supplied power.

Perhaps the OP originally had a defective pedal switch, but may have dislodged the A35 connector while working under the dash.
We purchased the Rav used 3 months ago with 37k miles on it. Was previously a lease.

There was a defective pedal switch in the glove box. So it would seem that at some point that the dealer replaced the switch. All was functioning properly until a few days ago when the referenced dash lights came on.

Thank you for all the help Rickl and Dr. Dyno. I would be lost without the guidance.
 

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I will look for A35 as well as inspect the shifter lock function after work and advise per Rickl's advice. How do you advise testing for continuity between A35 and Pin #4 at the relay socket?

While jumping pin 5 at the relay, in ignorance, I applied 12v to pin 1 prior to your warning. I hope that I didn't blow anything. A fan? did pop on when pin #1 was supplied power.
I really hope that nothing was damaged when you connected 12V to pin#1 at the relay socket. That pin is connected to the Skid Control ECU. Normally the ECU applies ground to the coil of the relay in order to operate it. SO the current through the ECU is limited by the relay coil resistance. If the ECU was sitting at ground potential (since the ignition was off) then a lot of current (with no limiting resistance) may have flowed through the ECU when the 12V was applied.

If your shift interlock works, then you already know that the pedal switch is working, and that you have continuity from the switch to the A35 junction.

To test for continuity I would suggest a small incandescent trouble light as the good Dr. Dyno has suggested. This is preferred because it is easier to see when working upside down under the dash, and it won't give erroneous voltage indications when detecting 12V on high impedance circuits (such as outputs from the ECU)

STEP #1
If the shift interlock doesn't work then I suggest putting a jumper across pins #1 & #2 of the brake switch, and then probing A35 with you test light. If you do see the voltage then remove the jumper and watch for the voltage while stepping on the pedal. If the interlock does work then you can skip this step.

STEP #2
You could also put a jumper between pins #5 & #4 of the relay socket ( i.e. connect 12V from the fuse back towards the A35 junction) and once again probe A35.

I'm pretty sure the problem is right in the A35 connector, so hopefully a visual inspection will prevent the need to perform any measurements.
 

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Discussion Starter #13
Rick,

I will advise this afternoon when I've had a chance to look into your suggestions.

Can you advise where the Skid Control ECU is located in a 2010 Rav4?
And is there a test to determine if I've fried anything?

Thank you agian
 

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Can you advise where the Skid Control ECU is located in a 2010 Rav4?
And is there a test to determine if I've fried anything?
I believe the Skid Control ECU is mounted on the firewall below the brake master cylinder.

I think your original warning lights on the dash were caused by whatever problem prevented your brake lights from illuminating. Once you get your brake lights to turn on with pedal pressure, then hopefully the dash lights will go off as well. If the dash lights remain on, that would indicate a possible new problem with the Skid Control ECU.
 

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Discussion Starter #15
The shifter lock function is working properly.

At first glance there does not appear to be any blatant issues with the A35 plug. It appears to be mounted in the factor install location.

Below is a wiring diagram from a 2011 Rav4 manual. (mine is a 2010)

It looks like beyond the A35 plug that the voltage may pass through A43 before going to the relay



I will first unmounted the A35 and see if Pin #19 is putting out 12v with the peddle pressed.
 

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The shifter lock function is working properly.
Below is a wiring diagram from a 2011 Rav4 manual. (mine is a 2010)
It looks like beyond the A35 plug that the voltage may pass through A43 before going to the relay
I have been looking at the wiring diagram from 2007. I have a number of supplemental PDF files for the 2011 model. One of them is dedicated to the brake lights. This makes me think the change was not made until 2011, so your 2010 should be wired according to my previous posts.

In the 2007 diagrams the "Stop Light Relay Control Assembly" does not exist. Instead the voltage from pin #2 of the pedal switch is connected to pin #3 of the A35 connector where it splits 3 ways.

CIRCUIT #1 Pin #8 of A35 sends the 12v to the STP port on the ECM, so that the ECM knows when you are stepping on the brake.

CIRCUIT #2 Pin #11 of A35 sends the 12v to the Shift Control ECM to unlock the shifter when you are stepping on the brake

CIRCUIT #3 Pin #9 of A35 sends the 12V to pin #4 of the relay. The voltage then passes through the normally closed contact of the relay and leaves on pin #3 to the brake lamps.

Each of these 3 circuits is on a different page of the 2007 manual.

You have proven that CIRCUIT #2 works because the shifter locks and unlocks when you step on the brake. That proves the brake switch is good, and the connection to A35 is good.

You have proven that CIRCUIT #3 is not working because you did not see voltage at pin #4 of the relay. You will need to find a wiring problem between the relay and Pin #9 of A35.

You don't know at this point if you have a problem with CIRCUIT #1, so just get the brake lights working, and then check for any remaining problems.

Here is the drawing for the brake lights from my 2007 manual.

Sorry for being so wordy:thumbs_up:

 

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Discussion Starter #17
Rick, your above post is extremely helpful.

Though, it would seem that under further investigation that the change was made in the VSC wiring between 2008 and 2009.

The Stop Light Switches changed from this in 2008:


To this in 2009 (which looks like mine):


Secondly the A35 block changed in 2008 from this:


To this in 2009:





When I jumper pin 2 to 1 at the switch all the blue wires at A35 receive 12v.


I guess my next culprit is this A43 (Stop Light Relay Control Assembly). Any idea where this is located? I do not have the full wiring book and am working off of pdf's.
 

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Discussion Starter #19
Found the relay. No continuity between Pin 2 and 8. Can jumper 2 to 8 on the car side an receive 12v on pin 4 at the relay.

Looks like I need a new Stop Lamp Control Relay.

Suggestions on where to buy?
 

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I wasn't aware there were so many wiring changes from one year to the next. I have PDF copies of both the 2007 and 2008 wiring manuals, and the brake light circuits were the same in both manuals.

I also have a PDF copy of just the 2011 Stop Light circuit which gave me the impression that the change was first made in 2011 and the supplement was issued to update the earlier drawings.

I have looked at your diagram and tried to determine why the wiring change was made. I assume that the relay was added so that all the current going to the rear lights did not have to travel through the pedal switch, and therefore extend it's life.

I think A43 simply supplies the 12v input on Pin #6 to the "out" port on pin #8 when it is triggered by the input signal from the pedal switch on pin #2. You wouldn't see continuity between pins #2 & #8 unless the relay had operated.

If that is the case then before replacing the unit I suggest verifying that pin #6 is receiving 12v and pin #4 is connected to a good ground. Also check that the 12v from the pedal is reaching pin #2.

Does A43 look like a typical relay or does it appear to be an electronic device?

Sorry I can't help you locate the part though.
 
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