There are self-diagnositic connectors on all models, when connected with the key ON (engine off), flash trouble codes on the LED light of the oxygen moniter of the ECU.
- The connectors are under the steering wheel, to the left of the module on most models.
- On carberated and SPFI injected 89 models,the test connectors are located on the engine side/driver's side of the firewall.
- Imprenza models have the ECU and test connectors located behind the right side of the dash, instead of the left.
- On SVX models the connectors are located behind the driver's side kick panel.
The codes are displayed as pulses of the LED mounted on the module. Long pulses (1.2 seconds) indicate tens and the short pulses (.2 seconds) indicate ones. Pulses are seperated by .3 second puses and codes are seperated by 1.8 second pauses. NOTE:on 89 MPFI models, the Oxygen Moniter light and ECU are mounted under the rear package shelf and are only accessible from the trunk.
On some later models the Check engine lamp and O2 monitor lamp flash the code(s) corresponding to the faulty part. The long segment (1.2 sec on) indicates a "ten", and the short segment (0.2 sec on) signifies a "one".
- 90 models - Trouble codes on the Justy are viewed on the Oxygen Moniter light, all other models the codes can be viewed on either the Oxygen Moniter light or the MIL (check engine light).
- 95 Imprenza and Legacy models have OBD2 systems and require a scanner,but some basic codes can be retreived using the flashing MIL method.
Codes will only clear when the faulty system or circuit has been repaired. After making the repairs, codes can be cleared by connecting 2 pairs of connectors, the "Self-diagnostic" connectors and the "Read Memory" connectors that are usually to the right of the diagnostic connectors.
- Start with a warmed up engine
- Turn off the engine
- Connect both pairs of connectors
- Fianlly start the engine
- This should clear the codes.
1988 and later models with Multi-Point Fuel Injection (including Legacy) 11 Crank angle sensor or circuit 12 Starter switch or circuit 13 Cam position sensor or circuit (TDC sensor on Justy) 14 Fuel injector no. 1 (Legacy, Impreza, Justy, SVX); Fuel injector 1 and 2 (XT, Loyale, GL, DL) 15 Fuel injector no. 2 (Legacy, Impreza, Justy, SVX); Fuel injector 3 and 4 (Loyale, GL, DL); Fuel injector 5 and 6 (XT6) 16 Fuel injector no. 3 (Legacy, Impreza, Justy, SVX); Fuel injector 3 and 4 (XT) 17 Fuel injector no. 4 (Legacy, Impreza, SVX); Fuel injector 1 and 2 (XT6) 18 Fuel injector no. 5 (SVX) 19 Fuel injector no. 6 (SVX) 21 Coolant temperature sensor or circuit 22 Knock sensor or circuit (right side on SVX) 23 Air flow meter or circuit (exc. Justy); Pressure sensor (Justy) 24 Air control valve or circuit (exc. Justy); Idle speed control solenoid valve (Justy) 25 Fuel Injector 3 and 4 (XT6) 26 Air temperature sensor (Justy) 28 Knock sensor no. 2 (SVX, left side) 29 Crank angle sensor (SVX, no. 2) 31 Throttle position sensor or circuit 32 Oxygen sensor or circuit (no. 1, right side on SVX) 33 Vehicle speed sensor (VSS) or circuit 34 EGR solenoid valve 35 Canister purge solenoid or circuit 36 Air suction solenoid valve (Impreza); Igniter circuit (Justy) 37 Oxygen sensor (no. 2, left side , SVX) 38 Engine torque control (SVX) 41 Air/fuel adaptive control 42 Idle switch or circuit 43 Throttle switch (Justy) 44 Wastegate duty solenoid (turbo) 45 Pressure duty solenoid (turbo)/atmospheric pressure sensor circuit (non-turbo) 49 Airflow sensor 51 Neutral switch (manual transmission)/inhibitor switch (automatic transmission) 52 Parking brake switch (exc. Justy)/Clutch switch (Justy) 55 EGR temperature sensor 56 EGR system 61 Parking brake switch (Loyale)/Fuel tank pressure control solenoid valve (Impreza) 62 Fuel temperature sensor (Impreza)/Electric load signal (Justy) 63 Fuel tank pressure sensor (Impreza)/Blower fan switch (Justy) 65 Vacuum pressure sensor