Engine Controls - Tests W/codes Mazda MPV V

INTRODUCTION

If no faults were found while performing BASIC TESTING , proceed with ENTERING SELF-DIAGNOSTICS. If no fault codes or only pass codes are present, proceed to TESTS W/O CODES for diagnosis by symptom (i.e. ROUGH IDLE, NO START, etc.).

HARD FAILURES

Hard failures cause "malfunction" light to illuminate and remain on until the malfunction 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, vehicle is functional, but loss of good driveability will most likely be encountered.

INTERMITTENT FAILURES

Intermittent failures may cause "malfunction" light to flicker or illuminate and go out after the intermittent fault goes away. The corresponding trouble code, however, will be retained in control unit memory. If related fault does not reoccur within a certain time frame, related trouble code will be erased from control unit memory. Intermittent failures may be caused by sensor, connector or wiring related problems. See INTERMITTENTS in TROUBLE SHOOTING (NO CODES) section.

Scheme 84

1. Using jumper wire, ground Green 1-pin connector. Connector is located at left front wheelwell. (Scheme 84) NOTE: On Federal MPVs, the CHECK engine warning light will come on every 80,000 miles to indicate oxygen sensor service is needed. To reset the light refer to «MAINTENANCE REMINDER LIGHT RESET PROCEDURES»(/mazda/mpv/v-1986-1991/remont/reset-procedures/#maintenance-reminder-light-reset-procedures).
2. With ignition on and engine stopped, observe "CHECK ENGINE" or MIL light. Note trouble codes. Check TROUBLE CODE IDENTIFICATION chart for possible cause. If light remains on continuously, MIL circuit is grounded or ECU is defective.

CLEARING TROUBLE CODES

1. Disconnect negative battery cable. Depress brake pedal for at least 5 seconds. Reconnect battery cable.
2. Ground test connector with jumper wire. Turn ignition on, but do not start engine for 6 seconds. Start engine and run at 2000 RPM for 2 minutes. Verify no codes are displayed.

SUMMARY

If no fault codes (or only pass codes) are present, proceed to TROUBLE SHOOTING (NO CODES) for diagnosis by symptom (i.e. ROUGH IDLE, NO START, etc.).

CODE CHARTS

Refer to the Trouble Code Identification table below and to Figs. 2 and 3 for definitions.

MPV 3.0L Trouble Code Identification (1 of 2). Scheme 85

MPV 3.0L Trouble Code Identification (2 of 2). Scheme 86

TABLE

TROUBLE CODE IDENTIFICATION

Code No.1 - Ignition Pulse (1989). Scheme 87

Code No.1 - Ignition Pulse (1990). Scheme 88

Code No.3 - G Signal. Scheme 89

Code No.8 - Airflow Meter. Scheme 90

Code No.9 - Water Thermosensor. Scheme 91

Code No.10 - Intake Air Thermosensor - Airflow Meter. Scheme 92

Code No.11 - Intake Air Thermosensor - Dynamic Chamber. Scheme 93

Code No.12 - Throttle Sensor. Scheme 94

Code No. 14 - Atmospheric Pressure Sensor

Replace Engine Control Unit

CODE 15: OXYGEN SENSOR

Note. When The Malfunction Code No. 15 And 17 Are Present At The Time, First Perform The Checking Procedure For The Malfunction Code No. 17.

Code No.15 - Oxygen Sensor. Scheme 95

Code No.17 - Feedback System. Scheme 96

Code No.25 - Solenoid Valve (Press. Regulator Ctrl) (1989). Scheme 97

Code No.25 - Pressure Regulator Solenoid Valve (1990). Scheme 98

Code No.26 - Solenoid Valve (Purge Control) (1989). Scheme 99

Code No.26 - Purge Control Solenoid Valve (1990). Scheme 100

Code No.34 - Idle-Speed Control Valve (Bac Valve) (1989). Scheme 101

Code No.34 - Idle Speed Control (1990). Scheme 102

Code No.41 - Solenoid Valve (Variable Resonance Induction System). Scheme 103

See also:
• MAINTENANCE REMINDER LIGHT RESET PROCEDURES
• CODE 1
• CODE 15