Sunday 24 July 2016

TOYOBD1 :: Online Glossary

TOYOBD1 This is the current application, it allows you to see and record the information listed below with an interval of about 1.3s between frames. this delay is inheritent of the Toyota OBD1 protocol and sadly we cannot make it any faster.

OBD1READ The tool needed to connect to you car,(No an OBD2 elm327 wont work instead ). Visit to order yours.
Here is how to hook OBD1READ to your car, please note that VF can be labeled VF1. Check the diagram present in the diag blox cover for exact connections.
On some cars, TE2 and E1 must be tied together into the DLC2 connector.(namely JZA80 and Lexus SC400)

INJ Injector opening duration in Millisecond for one engine Revolution

IGN Ignition advance angle in degrees before TDC, positive values indicate angles after TDC

IAC Percentage of opening of Idle air control valve

RPM Engine speed,please note that the OBD1 protocol cannot show speed above 6375 rpm :S

VAF/MAP/MAF This is the value measured by the metering system in volts, kpa or gr/sec depending on configuration

ECT Engine coolant temperature reading

TPS Throttle position sensor,range should be 0-90 degrees

SPD Vehicle speed sensor

STFT S.hort T.erm F.uel T.rim, it represents how much the ECU needs to compensate VS what he expected

MPG Fuel consumption calculation

Means that the A/C system is engaged
Means that the acceleration enrichment mode is on
Means that the after start enrichment mode is on
Means that unknown function word 11 bit 2 is on
Means that unknown function word 11 bit 3 is on
Means that unknown function word 11 bit 7 is on
Means that unknown function word 12 bit 6 is on
Means that Idle mode is ON, generally different ignition advance and extensive usage of IACV, TPS closed or closing
Means that knock sensor detects heavy knocking now
Means that the neutral start switch is on
Means that the ECU is now in open loop mode
Means that an oxygen sensor is reading a lean air fuel ratio mixture
Means that an oxygen sensor is reading a rich air fuel ratio mixture
Means the ECU detects the starter is engaged
Means that the ECU is in self diagnosis mode. it happens when the engine start and goes away when driving if the ECU suspects nothing wrong.
Means the engine is in warm up mode

Thermal Audio Alarm

When the engine water temp exceeds 100C or 212F and audio alarm will be heard telling you there is something wrong that you should take care of, RIGHT NOW.

Known Limits of Toyota OBD1

Protocol speed is 1.3s between frames( please remember this protocol dates back to the early 90s when that speed probably seemed sufficient). Another important limitation is that no engine speed above 6375 rpm will be displayed.

Communication Heartbeat

Useful for troubleshooting, this shows when a frame is sent from the ecu to toyobd1, if the ECU sends nothing there wont be an heartbeat at all.

About author

Toyobd1/OBD1READ was carried out in the winter of 20134-2014 by JF Breton with the 3VZ-FE in mind. Canadian programmer and toyophile mainly interested in all ECU stuff,3S-GTE celicas and strange projects.