Change Sat Nav Address Whilst Driving

[mooki24]

Hi all

Sorry if this post has already been written somewhere else, I did a search but couldn't find anything.

I have a new 2012 Rav4 with Sat Nav included, however I can't input an address unless the car is stopped. This is quite frustrating when my boyfriend is driving and I want to input the address.

Does anyone know if this can be turned off?

THanks

[vanib]

Check this link: Navigation Override?

[bob-o]

A lot of Toyota and Lexus owners are very unhappy about the lockouts. Unfortunately it takes quite a bit of logic circuitry to fool the nav system. It is not just a simple wire to disconnect like on some units in the past.

This unit will do the job on our cars and is plug & play, but it is $309

Prestigious Society » Navigation and Video Enhancement Module » Prestigious Society

The $129 unit looks good but I am not sure it will work on our units. I think mine has to be stopped completely, it only works on systems that let you use the functions up to 5 mph. need to check that.

[mooki24]

Thanks both Can't believe this is a bit of a tricky / expensive fix. Very annoying!!

[bob-o]

the unit Vanib linked to only has about $10 worth of parts in it, and a complete schematic, so if I find my car does not lock out between 0-5 mph I will build one and report on it.

[Dr. Dyno]

Originally Posted by bob-o

the unit Vanib linked to only has about $10 worth of parts in it, and a complete schematic, so if I find my car does not lock out between 0-5 mph I will build one and report on it.

Bob, looking at the explanation of the 4 mph equivalent square wave, using a 555 to generate it came to mind immediately. http://www.top4runners.com/cgi-bin/i..._schematic.jpg But why does he need a relay? Just use a SPDT switch to feed the NAV either the normal signal or the 4 mph one. Also why use pots, just use fixed resistor since anything below 5 mph apparently works? That gets you down to 5 components - the 555 two resistors & two caps. Could solder it all together and encapsulate it in clear RTV. A nice little blob with three wires sticking out.
Just some thoughts.

[bob-o]

He said he used the relay because he could not get an spdt switch that he liked. I expect he used the pot to avoid the need for precision resistors that would probably need to be special ordered, and the tolerance of cheap caps is usually 20% so choosing the right value would be trial and error or measuring the cap before choosing the resistor values.

On that topic, do you know a source for rocker switches matching the ones in the dash, without buying them from toyota?

I think that the new nav units also look at the ABS signals from each wheel to see when they are turning, so they can still show location in tunnels and car orientation. I'm not sure this simple fix will work on my car, but I'll check it out soon. If keyboard entry does work up to 5 mph I'll hook up a pulse generator and see if it works before building anything.

It's ridiculous that Toyota did this and still lets us fool with the audio system and entune apps while moving. IMO that is just as dangerous.

I've been using 555's since the first ones came out in '72; one of the most useful devices ever made, as attested to by the fact they are still around.

[Rickl]

Originally Posted by bob-o

I think that the new nav units also look at the ABS signals from each wheel to see when they are turning, so they can still show location in tunnels and car orientation. I'm not sure this simple fix will work on my car, but I'll check it out soon. If keyboard entry does work up to 5 mph I'll hook up a pulse generator and see if it works before building anything.

I have not heard of any NAV units which use the ABS signals, but many use the signal from the Vehicle Speed Sensor, or VSS as shown in the schematic. This signal is easily accessed on any vehicle with OBDII.

In addition to providing the NAV lockout feature, it is used for the purpose of Dead Reckoning. This allows the NAV unit to approximate it's location for short periods after it loses the satellite signal. This occurs when driving through tunnels or between highrise buildings. If the RAV does use this method, I don't quiet understand why you just can't remove the VSS signal altogether. Why build a circuit to make it look like the vehicle is moving slowly, when you can make it looked parked.

For example my Subaru Legacy with the factory installed Pioneer system never had the VSS connected even though the Pioneer HU has a connection for it. I have never had a situation where I would have benefited from Dead Reckoning.

Unfortunately some NAV units use the GPS receiver itself to determine if the vehicle is moving. This type would require disconnecting the GPS antenna in order to fool the system.

Other units simply require that the parking brake be applied in order to put a ground on the HU input. Of course these are the easiest to bypass.

Other NAV units make use of combinations of the three methods

[bob-o]

I guess I blast through 5 mph so quick with the V6 that it seemed not to work at slow speeds, but I just tested it and it does work up to 5 mph, so it seems mine likely works the same as the one in the post about defeating the lockout on a different model.

I don't see why it would need pulses at all either, unless maybe a function that sees the gps location moving and no pulses at all locks out in that condition as a "tamper" function. I'll try tying the signal low and see what happens, then the pulse gen. It's going to be sunny and nice tomorrow so I'm headed up to the snow for a few days first.

[Rickl]

Originally Posted by bob-o

I don't see why it would need pulses at all either, unless maybe a function that sees the gps location moving and no pulses at all locks out in that condition as a "tamper" function. I'll try tying the signal low and see what happens, then the pulse gen.

You are probably correct about the anti tamper function. After additional reading I have heard some people report that the speed pulses are required to defeat the lockout.