Subaru Coupes/Sedans/Wagons 1985-1996 Repair Guide

Reading Codes


Codes are displayed by the MIL flashing ON and OFF . The time duration of the flash identifies the significance of the digit. Three flash durations are used:

A flash duration of 0.5 seconds indicates no malfunction (OK).
A flash duration of 1.3 seconds indicates that it is a 10's digit.
A flash duration of 0.2 seconds indicates that it is a 1's digit.

For example, if 3 flashes-1.3 seconds long-are followed by 4 flashes-0.2 seconds long-a Code 34 is indicated. These code sequences are separated by 1.8 seconds to avoid confusing tens and ones digits.

Read Memory Mode : used to pull codes which have been stored in memory. It is most effective in detecting poor contact of wiring harness connectors. To enter this mode, connect the read memory connector with the ignition ON .
D Mode : used to diagnose and test the entire injection system. To enter this mode connect the test mode connector with the ignition ON . On the Legacy and SVX, the ignition must be ON with the engine running.
F-Check Mode : used to measure the performance characteristics of the injection system components. When working in this mode, a Select Monitor or equivalent scan tool is required.
U Check Mode : operates during normal engine operation. It signals the driver using the MIL only when components necessary for start-up and drive are faulty. The read memory and test connectors must be disconnected with the ignition ON for this mode to be operational.