Contents Section: Testing & Diagnostics All sections

Engine Controls - Tests W/codes - SOHC Suzuki Swift II

Testing & Diagnostics 34 illustrations ~749 words

INTRODUCTION

If no faults were found while performing BASIC DIAGNOSTIC PROCEDURES proceed with self-diagnostics. If no fault codes or only pass codes are present, 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, Electronic Control Module (ECM) 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 intermittent fault goes away. However, the corresponding trouble code will be retained in Electronic Control Module (ECM) memory. If related fault does not reoccur within a certain time frame, related trouble code will be erased from ECM memory. Intermittent failures may be caused by a sensor, connector or wiring related problems. See INTERMITTENTS in TESTS W/O CODES article in the ENGINE PERFORMANCE Section.

Scheme 41

Scheme 41: RETRIEVING CODES
  1. The CHECK ENGINE light will come on when ignition is on and engine is not running. When engine is started, CHECK ENGINE light should go off. If light remains on while engine is running, a trouble code is present.
  2. If light did not come on with key on and engine off, the CHECK ENGINE light circuit must be checked before continuing. See appropriate INITIAL DIAGNOSTIC PROCEDURE in this article if CHECK ENGINE light failed to operate. The initial diagnostic procedure is located with code charts.
  3. To retrieve codes, turn ignition off. Install fuse in diagnosis terminal at the fuse block, located behind left side of instrument panel. (Scheme 41) Turn ignition on and count number of flashes from CHECK ENGINE light.
  4. As an example, a Code 21 will be identified by a flash, flash, pause and flash. A long pause will exist and Code 21 will be repeated 3 times. (Scheme 42) Each additional code will flash 3 times.
  5. If system is operating properly (with no codes), a Code 12 should exist with ignition on and engine off. This indicates the diagnostic system is capable of storing codes.
  6. Once all codes are displayed, codes will be repeated. Remove fuse from diagnostic terminal in fuse block after codes are recorded.

Scheme 42

Scheme 42

CLEARING TROUBLE CODES

CAUTIONEnsure ignition is off when disconnecting or reconnecting power supply for ECM.

After repairs are performed, clear ECM memory of all stored trouble codes. To clear memory, turn ignition off. Disconnect negative battery cable for at least 30 seconds (Swift DOHC) or 60 seconds (Swift SOHC).

ECM LOCATION

ECM is located in upper left corner of instrument panel.

SUMMARY

If no hard fault codes (or only pass codes) are present, driveability symptoms exist or intermittent codes exist, proceed to TESTS W/O CODES article in this section for diagnosis by symptom (i.e. ROUGH IDLE, NO START, etc.) or intermittent diagnostic procedures.

DIAGNOSTIC TROUBLE CODE DEFINITIONS

CodeDescription
12System Normal
13Oxygen Sensor Circuit
14Coolant (Water) Temp Sensor (WTS) Indication Low
15Coolant (Water) Temp Sensor (WTS) Indication High
21Throttle Position Sensor Voltage High - A/T
22Throttle Position Sensor Voltage Low - A/T
23Air Temp Sensor (ATS) Circuit Indication Low
24Speed Sensor Circuit Check
25Air Temp Sensor (ATS) Circuit Indication High
31Pressure Sensor (PS) Signal Voltage Low
32Pressure Sensor (PS) Signal Voltage High
41No Ignition Signal
42Crank Angle Sensor
51 (1)EGR System Circuit Check
(1) Applicable to California models only.
(1)Applicable to California models only.

DIAGNOSTIC TROUBLE CODE DEFINITIONS

Scheme 43

Scheme 43: INITIAL DIAGNOSTIC PROCEDURE

Scheme 44

Scheme 44: CHART A1 - ECM POWER SUPPLY & GROUND CIRCUIT CHECK

Scheme 45

Scheme 45

Scheme 46

Scheme 46: CHART A2 - CHECK ENGINE LIGHT INOPERATIVE

Scheme 47

Scheme 47

Scheme 48

Scheme 48: CHART A3 - CHECK ENGINE LIGHT STAYS ON - WON'T FLASH

Scheme 49

Scheme 49

CODE 13 - OXYGEN SENSOR CIRCUIT

Before diagnosing trouble according to flow chart, check to make sure that the following system and parts other than EFI system are in good condition

  1. Air cleaner (clogged)
  2. Vacuum leaks (air inhaling)
  3. Spark plugs (contamination, gap)
  4. High-tension wires (cracks, deterioration)
  5. Distributor rotor or cap (wear, cracks)
  6. Ignition timing
  7. Engine compression
  8. Any other system and parts which might affect A/F mixture or combustion

If code No. 13 and another code are indicated together, the latter code has priority. Therefore, check and correct what is represented by that code first and then proceed to with code 13 check.

Be sure to use a voltmeter with high impedance (10,000 ohm/volt minimum) or digital volt ohmmeter for accurate measurement.

Scheme 50

Scheme 50

Scheme 51

Scheme 51

CODE 14 - COOLANT (WATER) TEMP SENSOR (WTS) INDICATION LOW

Note. When code 14, 23 and 32 are indicated together, it is possible that Light Green/Black wire is open or terminal A16 connection is poor.

Scheme 52

Scheme 52: CODE 14 - COOLANT (WATER) TEMP SENSOR (WTS) INDICATION LOW

Scheme 53

Scheme 53

Scheme 54

Scheme 54: CODE 15 - COOLANT (WATER) TEMP SENSOR (WTS) INDICATION HIGH

Scheme 55

Scheme 55

Scheme 56

Scheme 56: CODE 21 - THROTTLE POSITION SENSOR VOLTAGE HIGH - A/T

Scheme 57

Scheme 57

Scheme 58

Scheme 58: CODE 22 - THROTTLE POSITION SENSOR VOLTAGE LOW - A/T

Scheme 59

Scheme 59

Scheme 60

Scheme 60: CODE 23 - AIR TEMP SENSOR (ATS) CIRCUIT INDICATION LOW

Scheme 61

Scheme 61: CODE 24 - SPEED SENSOR CIRCUIT CHECK

Scheme 62

Scheme 62

Scheme 63

Scheme 63: CODE 25 - AIR TEMP SENSOR (ATS) CIRCUIT INDICATION HIGH

Scheme 64

Scheme 64

Scheme 65

Scheme 65: CODE 31 - PRESSURE SENSOR (PS) SIGNAL VOLTAGE LOW

Scheme 66

Scheme 66

Scheme 67

Scheme 67: CODE 32 - PRESSURE SENSOR (PS) SIGNAL VOLTAGE HIGH

Scheme 68

Scheme 68

Scheme 69

Scheme 69: CODE 41 - NO IGNITION SIGNAL

Scheme 70

Scheme 70

Scheme 71

Scheme 71: CODE 42 - CRANK ANGLE SENSOR

Scheme 72

Scheme 72

Scheme 73

Scheme 73: CODE 51 - EGR SYSTEM CIRCUIT CHECK - CALIF. ONLY

Scheme 74

Scheme 74

See also:
13
14
15