TOYOBD1 :: quickest way to test TPS operation

!! After doing this test procedure make sure to erase ECU error codes because unplugging the TPS while Ignition key is ON will store an error code. !!

This technique is only meant for 4 wires analog type TPS.

Typical 4 wires Toyota TPS

4 wires are reaching the TPS

1. E2 is a sensor ground 
2. IDL is telling the ECU if the throttle is at rest
3. VTA is the output signal telling the throttle opening angle
4. VC  is a sensor reference voltage, should be 5v or pretty close

First make sure the IDL switch is working inside the TPS

Without the Ignition key ON, unplug the TPS connector.

Using a multimeter you will test for continuity between E2 and IDL when the throttle is at rest. if you open the throttle plate big enough continuity will be loss, this is expected.

using a multimeter I'm testing for continuity between E2 and IDL

Testing with TOYOBD1 the ECU and wiring for proper operation

notice the absence of IDL flag here

With the Ignition key ON and engine not running, 

unplug the TPS connector. 

Launch TOYOBD1 and connect to your OBD1READ device. 

make sure you look at the TPS cell.

with no TPS connected you should get such readings

The IDL flag will not be shown, this is expected.

BE CAREFUL NOT TO BRIDGE E2 WITH VC OR ECU DAMAGE MAY OCCUR 

LOOKING INTO THE TPS CONNECTOR. with a jumper in place

notice the presence of the IDL flag

Now using a jumper wire you will bridge E2 and IDL.

you will get this reading in TOYOBD1, the IDL flag will be present.

if you don't get the IDL flag to show something is wrong with the wiring between TPS and ECU, or the ECU is damaged( less likely )

 

!! After doing this test procedure make sure to erase ECU error codes because unplugging the TPS while Ignition key is ON will store an error code. !!