Problems in VVT operation test

[k fuku]

VVT動作試験の問題点

エンジン停止状態でVVT動作試験を行うと、リンクecuとPC間の通信が遮断されます。

エンジン運転中に同じ運転試験を行うと、今回はエンジンが停止します。

ログを取得して添付しています。
それが何であるかわかりますか？

 

[Adamw]

It appears some wiring problem, maybe a bad ground or weak power supply.  Your logged battery voltage drops to 5.50V during cranking and before the ecu shuts off.

[k fuku]

I replaced the battery with a new, charged one, but when I check the voltage on the runtime screen, it shows 9.8V.

Power ground is installed in three places
(1) Cylinder head
Connected to the standard ECU power ground.
(3) Between cylinder head and battery
(3) Between cylinder head and battery.

I found that if I unplug the VVT valve connector, the link ECU does not turn on.

I checked the harness and found no wiring errors.
I tested by replacing AUX1 to AUX4.
The result was the same no matter where I connected them.
The test with the VSV valve worked fine.

The resistance value of the VVT valve itself was set to zero.

[Adamw]

2 hours ago, kurosiba fuku said:

I found that if I unplug the VVT valve connector, the link ECU does not turn on.

This is the biggest clue.  If the ECU does not power up with VVT unplugged this means the ECU has no +12V on pin A5.  Check power supply/fuse/relay to this pin.  Test with ECU unplugged so you dont get confused with back feeding through ECU.

 

 

[k fuku]

I looked into it as soon as possible.

As a test, I disconnected the main power wiring from the LINK ECU.
To my surprise, it was working without power input.
I wondered where the power was coming from.

The cause was the wrong wiring for the main power relay.

Thank you very much for your help