Tests W/codes - Mpfi Mazda 323 BF

INTRODUCTION

If no faults were found while performing BASIC DIAGNOSTIC PROCEDURES, proceed with ENTERING SELF-DIAGNOSTICS. 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.).

"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 47

1. Using jumper wire, ground Green 1-pin connector. (Scheme 47) Connector is located at back of left front wheelwell.
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. If no codes are found, go to ECU VOLTAGE TESTING in this article.

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.
3. 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.).

323 TROUBLE CODE IDENTIFICATION (1 of 2). Scheme 48

323 TROUBLE CODE IDENTIFICATION (2 of 2). Scheme 49

Code No.1 - Ignition Pulse. Scheme 50

Code No.8 - Air Flow Meter. Scheme 51

Code No.9 - Water Thermo Sensor. Scheme 52

Code No.10 - Intake Air Thermo Sensor. Scheme 53

Code No.14 - Atmospheric Pressure Sensor. Scheme 54

Code No.15 - Oxygen Sensor. Scheme 55

Code No.17 - Feedback System. Scheme 56

Code No.26 & 27 - Solenoid Valve. Scheme 57

Code No.34 - BAC Valve. Scheme 58