Stuart mcharg Posted September 17, 2019 Report Share Posted September 17, 2019 Hi guys, I'm needing some input / guidance around temp output/speedo to the standard dash on a jza80. So far my g4+ extreme can see my engine temp but I can't get it to send a signal to the dash, although I have tried several ways. As for the speedo I'm having problems with the input side. I have wires the stock 3wire sensor as follows Sp1 to di1 Sp2 to di2 Earth.. Earth. Any help would be much appreciated. These are the last things Iam having problems with. Quote Link to comment Share on other sites More sharing options...
cj Posted September 17, 2019 Report Share Posted September 17, 2019 In factory wiring the ECU doesnt control the dash temperature gauge. Thats fed by a second completely separate sensor on the engine. The ECU temp sensor is 2 wire, the dash sensor is 1 wire. Your speed sensor should be 1x wire to 12v, 1x wire to earth, and the third wire to a DI on the ECU (ie the signal wire) [edit] in factory wiring the VSS signal wire actually goes to the dash, and then there is a different output wire from the dash which you would run to a DI on the ECU. I cant tell if you are asking about the dash-> ECU wiring or are looking at the VSS directly. Quote Link to comment Share on other sites More sharing options...
Stuart mcharg Posted September 17, 2019 Author Report Share Posted September 17, 2019 Thanks for the reply mate. I guessed as much about the coolant sensor. I thought the ecu can tell its temp so why can't I relay that to the dash. The vss is strang on the jzx100 (which the engine is from) so the way its wired is to ecu then dash. Like you said the jza80 is wired to dash. Which would of been easy. I'll try changing the wiring around. My wiring diagram stated sp1 sp2 and earth. So I'm guessing sp1 or 2 is 12 v Quote Link to comment Share on other sites More sharing options...
cj Posted September 17, 2019 Report Share Posted September 17, 2019 is that diagram from an 80 or a 100? and are those pins on the speed sensor, the ecu, or the dash? typically you can wire it up the other way around without much issue on the toyotas as the dash is expecting a square wave/pwm - so you wire the speed sensor up to the ECU on a DI, then pass it through to a PWM aux out and connect this to the dash "speed input" pin. This also allows you to do speedo corrections for wheel size etc Quote Link to comment Share on other sites More sharing options...
Stuart mcharg Posted September 22, 2019 Author Report Share Posted September 22, 2019 I've tried doing it both ways. Tried to check for anything coming out the sensor, nothing.. Tried changing around the wires. There isn't a clear wiring diagram online. I have a 3 wire sensor Black wire earth Blue /white power Black / white signal I'm thinking I have a sensor fault. Quote Link to comment Share on other sites More sharing options...
cj Posted September 22, 2019 Report Share Posted September 22, 2019 Have look at the pinout info here https://www.shoarmateam.nl/content/toyota-speed-sensor/ note the little tab on the bottom next to 1 of the pins, this shoudl help determine if pin1 is left/right of the sensor or the plug. One the ECU you want that signal wire to come into a DI, and I think you want pullup resistor off (assuming you are not running it to dash). The other possibilty here is that the wires at the speed sensor do go to the dash, and somethign isnt wired up here, and because of this the speedo out (to ecu) will also not work, and this maybe what you are testing at the ECU end. Quote Link to comment Share on other sites More sharing options...
Stuart mcharg Posted September 22, 2019 Author Report Share Posted September 22, 2019 That's the guide I was going off. It seems backwards to me. There power wire shown is my earth. I have hooked it upto di1 and out words from aux4 as speedo out. In the speedo settings I have set it to di1 and calibration 0 as for now. I can put my aux4 to test pwm and it works perfect. Quote Link to comment Share on other sites More sharing options...
cj Posted September 22, 2019 Report Share Posted September 22, 2019 what if you set DI1 to "frequency". do you get anything? You say your wiring has the power & earth the other way around... is this a factory wiring harness? If you've built it, maybe those 2 wires are backwards? That page, the 97 supra service manual i've got, and the wiring diagram in the same manual all show pin 1 (far end from the notch) as 12v and center as earth. Quote Link to comment Share on other sites More sharing options...
Stuart mcharg Posted September 22, 2019 Author Report Share Posted September 22, 2019 Nothing atal. Well I traced the wiring. The black joins another black wire which is earth for the reverse switch. I can wire it up which ever way. I think I'll pull the sensor and try it that way for sure. I did try putting power down the two different wires and testing the voltage out words. With one way I got nothing the other I got battery voltage out. Which didn't change regardless of sensor movement. I shall try the sensor out of the car and in test Quote Link to comment Share on other sites More sharing options...
Stuart mcharg Posted September 30, 2019 Author Report Share Posted September 30, 2019 On 9/22/2019 at 6:43 PM, cj said: what if you set DI1 to "frequency". do you get anything? You say your wiring has the power & earth the other way around... is this a factory wiring harness? If you've built it, maybe those 2 wires are backwards? That page, the 97 supra service manual i've got, and the wiring diagram in the same manual all show pin 1 (far end from the notch) as 12v and center as earth. Thanks for the help dude. Sensor turned out to be good. Traced the wiring back half way to the box and someone had put a link section in. They put the earth with the power.. As for the coolant I fitted a second sensor and run the wires direct to the dash.. Quote Link to comment Share on other sites More sharing options...
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