ECS, LDWS, and Auto Hold lights on AFTER unplugging OBDII scan tool

[MrBrady]

I've been having all kinds of problems with my brakes latest. Replaced the rotors, pads, master cylinder and when started driving, the brakes suddenly started dragging like crazy.

Towed the car to a brake shop and they said the HECU is bad. However, while diagnosing with a scan tool, I noticed that the car will sometimes behave totally fine with no dash warning lights. But once I plug in and unplug a scan tool, the ECS, LDWS, and auto hold lights turn on. Also getting intermittent issues with the scan tool being unable to communicate with the car.

Has anybody had a similar issue and have suggestions for how to fix?

EDIT: Now I'm unable to reproduce it. No lights on the dash, but the brakes are definitely dragging.

 

[Gunkk]

LDWS is not normally associated with the brakes, so that sounds like a canbus issue. And if it's only happing when you plug in your scan tool, then I'd suspect the scan tool. Anything that touches the canbus can affect the canbus, including what you plug into the OBD2 port. Have you tried a different one?

 

[MrBrady]

Turns out the scan tool we were using had incorrect pin configuration in the big tablet scan tool. Side note: To diagnose, I picked up a TOPDON TopScan OBDII scanner that connects to my iPhone. Works great and is very feature packed for such an inexpensive bluetooth scanner.

Waiting for a rebuilt HECU to arrive to fix the issue.