TOYOCOM :: Adding custom pressure sensors

Adding custom pressure sensors for use with a TOYOCOM device

Today I will show you how to add a third party oil/fuel pressure sensor to an ST205 3S-GTE wiring harness. this sensor is only going to be useful if used with a TOYOCOM device & TOYOBD1 android app. No other system care for it's reading and it cannot affect the engine performance adversely.

ST205 bench harness used for the demonstration

The 0-100 psi oil/fuel pressure sensor we will be using

This sensor is found easily on E-BAY for about 20 CAD each, comes with it's pig tail and can be ordered for various pressure ranges. In the case of most Toyota engines, an oil pressure reading of 0-100 psi seems adequate. Similarly fuel pressure on those engines are not meant to reach 100 psi so this range is fine for both uses.

The pin out if this sensor is very simple. (if in doubt with a particular model ask me)

1. BLACK = sensor ground (goes to Toyota wiring E2)
2. RED = sensor reference voltage(goes to Toyota wiring VC)
3. GREEN =  output signal , this goes straight to the TOYOCOM device only.

 

The ST205 ECU wiring diagram with today's additions

Show below is the test bench incarnation, only aligator clips wires have been used. In real life solder and isolate your wires The new green wire has been routed in an empty spot of the diagnosis box , into VF2, the matching VF2 pin of the TOYOCOM device can read 0-5v analog signals or frequencies. Red and black wires have been tied to TPS wires due to the ease of locating them, depending on your specific cases those same wires could be had near a MAP sensor also. please ask if in doubt.

 

 

 

 

 

 

 

  

 

You can now plug in your TOYOCOM device and power the whole system

 Now the Software configuration

In the TOYOBD1 app you will need to have already paired and connect to your TOYOCOM device, you will also need to have set the display configuration to see the VF2 input.Then we will be able to apply the sensor curve to this input and get what we want.

Sensor curve for use in TOYOBD1

The curve for use with this sensor is available on dropbox HERE

 Now click/zoom into the VF2 signal cell, it will not have a sensor curve applied yet.

Then press on the 'ADC' button to prompt the sensor curve selector dialog, there are a few key built in sensor curves but the oil/fuel pressure curve is not built in yet and requires to be read from a file.

 Now press on the '...' button to search for a sensor curves, I placed the file into my TOYOBD1 directory, press OK, then back into the sensor curve selector press apply sensor curve.

 At that time the VF2 cell will have changed, it will not show the measurement unit from the selected curve, if you don't have a gauge but text display and wishes the gauge, just swipe left/right on it , it will come.

Whole screen after clicking/zooming out of the VF2 cell. at this point you are ready to see useful oil/fuel pressure next time you go for a drive.

TOYOCOM : pre-production teaser

 TOYOCOM & OBD1FAN

A replacement for the OBD1READ is brewing since a fairly long time and is now into beta testing.
The new device is meant to replace the earlier OBD1READ 22p and bare. it allows to get the same toyota obd1 data stream and more. offered with the plug and play connector only, it aims to use  every wire available in the cable.depending on the particular car, those diagnosis box contacts may already be populated by other systems, in which case I suggest thinking carefully if you want to modify the diagnosis box pinout or grow one exclusively for usage of TOYOCOM.

only connections present in the plug and play cable.

 
Externally the new tool remains nearly the same ,retaining it's blue clear case. a yellow led was added to let the user know when the obd1 data stream sent by the ECU is received correctly by the tool. This feature allows for better troubleshooting.

TOYOCOM & OBD1FAN  devices are compatible with the already existing TOYOBD1 application and basic usage is similar to the OBD1READ. TOYOBD1 on google play 

the OBD1FAN variant which additionally allows radiator fan control .

Pre-production TOYOCOM Features

• Ligth up a yellow led when the obd1 data stream is active and properly received by the tool.
• activate/deactivate the obd1 data stream from the android application
• read the obd1 data stream when active , sending each field directly. this improvement over the OBD1READ allows to see the data on the screen when it is fresh instead of 1.3s later.
• activate/deactivate ECU error code output
• read the ECU error codes and display them in the android app with a textual meaning
• lock ignition timing when conditions are met, allowing to adjust base ignition timing if applicable
• read battery voltage 10 times per second
• read 1x 0-20v analog signal 10 times per second
• *read up to 2x  0-1000hz frequency signals 5 times per second
• *read up to 4x 0-5v analog signals 10 times per second

0-5v analog inputs into TOYOCOM

0-5V analog inputs suggestion

• THA or PIM sensor, or all other missing from the obd1 stream
• Wideband AEM gauge output signal
• custom added sensors, oil pressure, fuel pressure, additional temp sensors,exhaust back pressure sensors,etc

0-1000hz frequency inputs into TOYOCOM

frequency inputs suggestion

• IGF signal, gives RPM and ignition coil dwell time
• SPD signal, gives differential rotation speed
• one injector negative wire, gives injector PW duration
• VVT solenoid one equipped engine. tells us VVT usage
• monitoring IGF,SPD and injectors allows to calculate fuel MPG in the android app

0-20v analog inputs into TOYOCOM

0-20V analog inputs suggestion

• TT signal when available from the A/T ECU ,tells the selected gear
• dashboard water temp sensor
• dashboard oil pressure sender unit
• dashboard fuel level sender unit

 *some inputs can do both frequency or analog inputs depending on configuration in the android application

 

Pre-production OBD1FAN Features 

• everything TOYOCOM does
• control radiator fan relays according to readings either from the obd1 stream or direct sensor readings
• warn the user of an overheating or malfunctionning fan condition through dashboard light bulb

 

preliminary OBD1FAN wiring diagram

 

New use cases handled by the new tool 

• Allows to directly read sensors we could not get information from in the obd1 data stream.
• Allows to directly read sensors that you added, oil pressure, fuel pressure, etc
• Allows to use on earlier toyota EFI cars with direct readings. giving partial support into TOYOBD1
• Read ECU error codes. 

OBD1FAN fan control features

• Allow to specify the Fans activation and deactivation temperatures
• Allow to control fan activity from obd1 data stream or direct sensor readings for earlier cars
• Allow to engage fans in a preemptive mode meant for traffic jam and track usage.
• Allow to disengage fans below a set voltage,( helpful in winter cold starts or alternator failure) 
• Allow to warn the driver of an overheating condition past a set temperature