INTRODUCTION
If no faults were found while performing BASIC TESTING , proceed with self-diagnostics. If no fault codes or only pass codes are present after entering self-diagnostics, proceed to TESTS W/O CODES article in the ENGINE PERFORMANCE Section for diagnosis by symptom (i.e. ROUGH IDLE, NO START, etc.).
HARD FAILURES
Hard failures cause CHECK ENGINE light to illuminate and remain on until problem is repaired. If light comes on and remains on (light may flash) during vehicle operation, cause of malfunction must be determined using diagnostic (code) charts. If a sensor fails, control unit will use a substitute value in its calculations to continue engine operation. In this condition, commonly known as limp-in mode, the vehicle runs but driveability will not be optimum.
INTERMITTENT FAILURES
Intermittent failures may cause CHECK ENGINE light to flicker or illuminate and go out after the intermittent fault goes away. However, the corresponding trouble code will be retained in ECU memory. If related fault does not reoccur within a certain time frame, related trouble code will be erased from ECU memory. Intermittent failures may be caused by a sensor, connector or wiring related problems. See INTERMITTENTS in the TESTS W/O CODES article in the ENGINE PERFORMANCE Section.
RETRIEVING CODES
- Enter specific test mode by connecting or disconnecting read memory and/or test mode connectors as shown in RELATIONSHIP BETWEEN MODES & CONNECTORS table. Connectors are located behind left side of dash. (Scheme 37)
- On Justy carbureted, observe O2 sensor monitor light, located in ECU. Note trouble codes, if any. Long illumination periods of 1.2 seconds designate the tens digit in the numbered codes. Short illumination periods of.2 second designate the ones digit in the numbered codes.
- Tens and one digits are separated by a.03-second interval of non illumination. Example: 3 long flashes (1.2 seconds each), followed by 5 short flashes (.02 second each) designate code 35.
- Code is repeated after a break of 2 seconds, unless another code is present which will be displayed after the 2-second break. Once all codes have been displayed, sequence will repeat.
Scheme 37
| Mode | Read Memory Connector | Test Mode Connector |
|---|---|---|
| U-CHECK (1) | Disconnected | Disconnected |
| READ MEMORY (1) | Connected | Disconnected |
| D-CHECK (1) | Disconnected | Connected |
| CLEAR MEMORY (2) | Connected | Connected |
| (1) Key on, engine off. (2) Key on, engine running. | ||
| (1) | Key on, engine off. |
| (2) | Key on, engine running. |
RELATIONSHIP BETWEEN MODES & CONNECTORS
TROUBLE CODE IDENTIFICATION
| Code | Circuit Affected | Probable Cause |
|---|---|---|
| 14 | Duty Solenoid (Fuel Control) | Open/Short Circuit |
| 15 | Coasting Fuel-Cut (CFC) System | Open/Short Circuit |
| 16 | Feedback System | D-CHECK Improperly Performed |
| 17 | Fuel Pump & Automatic Choke | Unit Failure |
| 21 | Coolant Temperature Sensor | Open/Short Circuit |
| 22 | VLC Solenoid Valve (1) | Open/Short Circuit |
| 23 | Pressure Sensor | Open or Shorted Test Solenoid Valve |
| 24 | Idle-Up Solenoid Valve | Open/Short Circuit |
| 25 | Float Chamber Vent Sol. Valve | Open/Short Circuit |
| 32 | Oxygen (O2) Sensor | Open/Short Circuit Or Defective Sensor |
| 33 | Vehicle Speed Sensor (VSS) | Faulty Sensor Or Control Unit |
| 34 | EGR Solenoid | Open/Short Circuit Or Defective Valve |
| 35 | Canister Purge Control Solenoid | Open/Short Ckt Or Faulty Valve |
| 41 | Feedback Carb System (Calif. Only) | Mechanical Fault |
| 46 | Radiator Fan Control | Fan Motor, Relay, Open/Short Circuit |
| 52 | Clutch Switch | Open/Short Circuit |
| 53 | High Altitude Compensator Valve | Open/Short Ckt Or Faulty Valve |
| 55 | EGR Sensor | Open/Short Ckt Or Faulty Sensor |
| 62 | Idle-Up System | Faulty Headlight/Defogger Switch |
| 63 | Idle-Up System | Faulty Fan/Radiator Switch |
| (1) Vacuum/Pressure Sensor Line Control (VLC) solenoid valve. | ||
| (1) | Vacuum/Pressure Sensor Line Control (VLC) solenoid valve. |
TROUBLE CODE IDENTIFICATION
CLEARING CODES
After malfunction has been corrected, trouble code will clear from memory when CLEAR MEMORY mode is accessed. Unless all items check okay in D-CHECK mode, memory will not be cleared. Refer to the RELATIONSHIP BETWEEN MODES & CONNECTORS table.
ECM LOCATION
Justy ECM is located behind the left dash panel.
SUMMARY
If no hard fault codes (or only pass codes) are present, driveability symptoms exist or intermittent codes exist, proceed to the TESTS W/O CODES article in the ENGINE PERFORMANCE Section for diagnosis by symptom (i.e. ROUGH IDLE, NO START, etc.) or intermittent diagnostic procedures.
| Abbreviation | Color |
|---|---|
| BR | Black/Red |
| BW | Black/White |
| BY | Black/Yellow |
| G | Green |
| GB | Green/Black |
| GL | Green/Blue |
| GR | Green/Red |
| GW | Green/White |
| GY | Green/Yellow |
| Lg | Light Green |
| LgB | Light Green/Black |
| LR | Blue/Red |
| LW | Blue/White |
| LY | Blue/Yellow |
| RY | Red/Yellow |
| W | White |
| WB | White/Black |
| WR | White/Red |
| WY | White/Yellow |
| Y | Yellow |
| YL | Yellow/Blue |
| YR | Yellow/Red |
| YW | Yellow/White |
WIRE COLOR ABBREVIATIONS
Note. The following diagnostic flow charts and mini-schematics are courtesy of Subaru of America, Inc.
In "NO TROUBLE" Condition
| Engine & Connector Conditions | "CHECK ENGINE" Light should Be | O2 Monitor Lamp Should Read |
|---|---|---|
| Engine On, Read Memory Connector Disconnected, Test Mode Connector Disconnected | Off | O2 Monitor |
| Engine On, Read Memory Connector Connected, Test Mode Connector Disconnected | Blinking | O2 Monitor |
| Engine On, Read Memory Connector Disconnected, Test Mode Connector Connected | Blinking | Off |
| Engine Off (1) , Ignition Switch On, Read Memory Connector Disconnected, Test Mode Connector Disconnected | On | Vehicle Specification Code Displayed |
| Engine Off (1) , Ignition Switch On, Read Memory Connector Connected, Test Mode Connector Disconnected | Blinking | Off |
| Engine Off (1) , Ignition Switch On, Read Memory Connector Disconnected, Test Mode Connector Connected | (2) On-Blinking | Vehicle Specification Code Displayed |
| (1) Before starting the engine, the Self-Diagnostic system assumes the engine to be in a "NO TROUBLE" condition. (2) The indication is not changed until the engine is operated at a speed greater than 1500 RPM for at least 39 seconds. | ||
| (1) | Before starting the engine, the Self-Diagnostic system assumes the engine to be in a "NO TROUBLE" condition. |
| (2) | The indication is not changed until the engine is operated at a speed greater than 1500 RPM for at least 39 seconds. |
BASIC OPERATION OF SELF-DIAGNOSTIC SYSTEM - NO TROUBLE MENU
During "TROUBLE" Conditions
| Engine & Connector Conditions | "CHECK ENGINE" Light should Be | O2 Monitor Lamp Should Read |
|---|---|---|
| Engine On, Read Memory Connector Disconnected, Test Mode Connector Disconnected | On | Trouble Code |
| Engine On, Read Memory Connector Connected, Test Mode Connector Disconnected | On | Trouble Code (Memory) |
| Engine On, Read Memory Connector Disconnected, Test Mode Connector Connected | (1) Off | Vehicle Specification Code Displayed |
| " | (1) On | Trouble Code |
| Engine Off, Ignition Switch On, Read Memory Connector Disconnected, Test Mode Connector Disconnected | On | Trouble Code |
| Engine Off, Ignition Switch On, Read Memory Connector Connected, Test Mode Connector Disconnected | On | Trouble Code (Memory) |
| Engine Off, Ignition Switch On, Read Memory Connector Disconnected, Test Mode Connector Connected | (1) On | Vehicle Specification Code, Then Trouble Code |
| (1) The indication is not changed until the engine is operated at a speed greater than 1500 RPM for at least 39 seconds. | ||
| (1) | The indication is not changed until the engine is operated at a speed greater than 1500 RPM for at least 39 seconds. |
BASIC OPERATION OF SELF-DIAGNOSTIC SYSTEM - TROUBLE MENU
Flow Chart - Basic Trouble Shooting Procedures. Scheme 38
Flow Chart - Read Memory Mode. Scheme 39
Flow Chart (1 of 2) - D-Check Mode. Scheme 40
Flow Chart (2 of 2) - D-Check Mode. Scheme 41
Wiring Schematic - Code 14, Duty Solenoid Valve. Scheme 42
Flow Chart - Code 14, Duty Solenoid Valve. Scheme 43
Wiring Schematic - Code 15, Coasting Fuel Cut (CFC) System. Scheme 44
Flow Chart - Code 15, Coasting Fuel Cut (CFC) System. Scheme 45
Flow Chart - Code 16, Feedback System. Scheme 46
CODE 17: FUEL PUMP & AUTOMATIC CHOKE
When Code 17 appears, replace fuel pump and automatic choke unit.
Scheme 47
Scheme 48
Scheme 49
Scheme 50
Scheme 51
Scheme 52
Scheme 53
Scheme 54
Scheme 55
Scheme 56
Scheme 57
Scheme 58
Scheme 59
Scheme 60
Scheme 61
Scheme 62
Scheme 63
Scheme 64
Scheme 65
CODE 41: FEEDBACK CARB SYSTEM (CALIF. ONLY)
Code 41 refers to mechanical problems such as clogged carburetor jets, etc.
