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RicardoJM
09-10-2010, 07:16 AM
The OBDII port on my LX470 does not have constant power with the ignition turned off. The port has power with the ignition turned on. My FSM shows a fuse in the drivers side kick panel labeled for OBD. I pulled this fuse and it tests ok for continuity on the multi-meter. I searched the 100 series forum on MUD but did not find any occurrences of this issue. What might my next debugging steps be?

The no power issue came to light as I installed my UltraGauge. The UltraGauge will initiate a scan after loosing power. I tested the UltraGauge in the Bronco and it works fine, i.e. it goes into sleep mode as when the ignition is turned off. In my Lexus, the UltraGauge works fine while the truck is running, but as soon as I turn the ignition off it looses power and starts scanning versus going into sleep mode.

TIMZTOY
09-10-2010, 09:17 AM
There not supposed to have power with the ign turned off ! That's why when you go into a shop to haventhe code read. They ask for the keys. You could also have a "link error" as most gauges would list. Were your not getting power to the port. I'd recommend finding a wiring diagram for the port and text the power wires there should be 2. One for key and one for supply.

RicardoJM
09-10-2010, 10:28 AM
There not supposed to have power with the ign turned off !

I hear you, but the UG support indicated that constantly having power is part of the OBDII standard.

You could also have a "link error" as most gauges would list. Were your not getting power to the port. I'd recommend finding a wiring diagram for the port and text the power wires there should be 2. One for key and one for supply.

I have the full FSM (2 big thick books) and there is a diagram of the OBDII connector, but the terminology they are using is tripping me up a bit. I don't have it here at work, but will post up tonight. Perhaps one of you fellas with more experience will be able to help me figure out which connection points to put the multi-meter on to sort things out.

Hulk
09-10-2010, 01:29 PM
OBDII doesn't have constant power in my '96 FZJ80 either. Otherwise my Scan Gauge would be lit all the time, drain my battery, and leave me stranded in Mexico.

nakman
09-10-2010, 02:03 PM
OBDII doesn't have constant power in my '96 FZJ80 either. Otherwise my Scan Gauge would be lit all the time, drain my battery, and leave me stranded in Mexico.

Yeah but something's there... the Ultra Gauge goes dark as well as soon as you turn the truck off, but I can leave the Ultra Gauge plugged into the 80 for a week, and when I start it up it remembers how much gas I've got left, all the averages it's calculated, etc. Does your Scangauge keep your settings?

If I understand Ricardo correctly on his 100 it's as if the gauge is starting over from scratch every time he starts the truck.

corsair23
09-10-2010, 02:14 PM
OBDII doesn't have constant power in my '96 FZJ80 either. Otherwise my Scan Gauge would be lit all the time, drain my battery, and leave me stranded in Mexico.

Actually, I believe it does.

The SGII has non-volatile memory to store settings etc. but AFAIK, the SGII doesn't have a battery in it. However, hit the red "home" button and the SGII will turn on, even with the key out of the ignition.

You can't scan for codes with the truck off as I've tried that (i.e. no power to the ECU), but you can change your gauges around, change your settings, set up the X-gauges, etc. without having the truck running. Based on this my guess is the SGII is getting power from the OBDII port.

RicardoJM
09-11-2010, 09:59 AM
Just an update. I was able to sort out the pins. There are 4 pins total; power, pulsed (signal from the OBDII system), signal ground and chassis ground. The power pin does indeed have power when the ignition is off and on - constant power:thumb:.

The next diagnostic check will be the ground portion of the circuit. Specification indicates the resistance should be .1 ohm.

RicardoJM
09-12-2010, 07:32 AM
I checked the ground pins and they have continuity and the reading is in spec. Interestingly they ohm reading goes up when the ignition is turned on. It is still very small, like .3 to .4 ohms but I was surprised to see it jump up.

So, my thread title needs to be changed. My OBDII port does have constant power. My UG works in the Bronco but not in the Lexus. My next step will be to test the UG in my wife's Camry and neighbors UZJ100.

RicardoJM
09-24-2010, 08:32 AM
I reported my results to UltraGauge support and they had me send my unit in for update. The unit came back last night and is working fine. Now, I have to see where Nakman decides to mount the UG in a 100 series.

thelal
06-24-2011, 10:21 AM
I purchased an Ultra-Scan for my 97' 80 for a round-trip (3300 miles) up/back to Seattle. Was most interested in mpg readings and Engine/oil temps

Very happy with it and should have bought this yrs again for the info it gives and the piece of mind. Engine temps were steady around the 185-190f and climb to 205f on long mountain passes.

I averaged 15.1mpg overall (pleased with that) with wife, 3 kids, luggage, heavy tool chests, no roof rack, heavy front/rear bumpers + swing-out tire carrier, hydraulic winch on front. Ran a/c quite a bit and speed averaged around the 68-75 mph. Fuel prices were between $3.65-3.95 (end of May). Tires 265/75/16 Treadwrights with 45psi+

Mounted mine on a metal piece (from kids lego set or something) that fitted between the (glued) wood trim below the console.

Brendan in Longmont, 97 80 with 235K