Diagnostic code #4

klol
Posts: 4
Joined: Tue Aug 26, 2014 12:50 am

Diagnostic code #4

Postby klol » Sat Aug 30, 2014 5:24 pm

Aloha, got a JAPAN ae86 with stock 4age motor. I have a diagnostics code # 4 flashing when diagnostic port is jumped. I have replaced the coolant temp sensor in back of the block (the green one), check engine light still exists. Can't clear light(no one I know has the right scanner), same code after replaced with new sensor, even when I disconnect the battery and press brakes to kill power the CFL is still on! Even on first start up..

jdm86gtz
Club4AG Expert
Posts: 308
Joined: Fri Jan 11, 2013 10:13 pm
Location: Ireland

Re: Diagnostic code #4

Postby jdm86gtz » Mon Sep 01, 2014 8:05 am

The right scanner is remove the EFi fuse for at least 5 seconds or disconnect the battery. As the fault is still there after you reconnected the battery it is an active fault.
Check for broken wiring or dodgy connection at the sensor. There should be 2 wires going into the connector, 1 from the ecu (green) and the other is an earth (brown).