Reading Codes
 

1990 4Runner 4WD Manual 3VZ-E 214,000 miles


Some one please let me know if I understand this principle correctly:


Plug in an OBDII DIAGNOSTIC SCAN TOOL in to the Data Link Connector under the hood. This will let you read error coeds generated by your Engine Control Module (ECU). Cross reference these codes to the Factory service manual (FSM). This will lead you to error.


As I understand it error codes are stored in the ECU memory until they are cleared out. Some how you can view these old error codes using an OBDII DIAGNOSTIC SCAN TOOL.


I know there is a specific Toyota scan that cost several thousand dollars. Is there difference between the Toyota scanner and the ones sold a my local parts store?


Are there any particular brands that are good/bad?

uh... for a 1990? sure ill tell you a diagnostic tool that costs about a penny, if that even. one paper clip. jump 2 terminals (e1 and t1 if i remember correctly, someone will correct me if im wrong) and that will put your ECU into diagnostic mode, and the check engine light will flash in a sequence. that sequence is the code.
such as code 52: 5 flashes, pause, 2 flashes.

I had read about that. I'm a bit lazy and don't mind buying to borrowing a scanner. Auto Zone will also read codes for free.

Using the paper clip method will it display old and or multiple error codes? Will it allow you to clear codes?

This does not look good. The connection here seems to covered in some kind of goo.

I tried the paper clip in TE1 and E1. Turn the key to on. The light just stayed on. How long does it take?

http://www.bishopart.com/4runner/code.png

That "goo" is dielectric grease to keep water out of those terminals.

If the light just stayed on, most likely you didn't have a good connection with the paper-clip. If there are no codes, the CEL will flash continuously with no long pauses.

It worked code was 51