Engine Controls - Tests W/codes Mazda Protege BG

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 H - TESTING W/O CODES article for diagnosis by symptom (i.e. ROUGH IDLE, NO START, etc.).

HARD FAILURES

Hard failures cause malfunction 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 TESTS W/O CODES article.

RETRIEVING CODES

1. Use Self Diagnostic Checker (49 H018 9A1) and System Selector (49 B019 9A0) to retrieve trouble codes. Connect one lead of self diagnostic checker to ground and the other to system selector. Connect system selector to data link connector. (Scheme 1)
2. With ignition on and engine off, verify No. 88 flashes on display and buzzer sounds for 3 seconds. If No. 88 does not flash, check main relay, power supply circuit and connector wiring. Repair or replace as necessary. If No. 88 flashes and buzzer sounds for more than 20 seconds, check for short circuit between ECM terminal 1E and data link connector. Replace ECM as necessary and reconnect test equipment.
3. Note trouble codes. Check «TROUBLE CODE IDENTIFICATION»(/mazda/protege/bg-1989-1994/remont/testing-diagnostics/#engine-controls-tests-wcodes) chart for possible cause. If more than one code is present, codes will be displayed in numerical order. Clear codes after repairs are complete. See «CLEARING CODES»(/mazda/protege/bg-1989-1994/remont/testing-diagnostics/#engine-controls-tests-wcodes__clearing-codes).

Scheme 1

CLEARING 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.

Scheme 2

SUMMARY

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.).

TROUBLE CODE IDENTIFICATION TABLE

TROUBLE CODE IDENTIFICATION

Scheme 3

Scheme 4

Scheme 5

Scheme 6

Scheme 7

Scheme 8

Scheme 9

Scheme 10

Scheme 11

Scheme 12

Scheme 13

Scheme 14

CODE 14: ATMOSPHERIC PRESSURE SENSOR

Replace ECU.

Scheme 15

Scheme 16

Scheme 17

Scheme 18

Scheme 19

Scheme 20

Scheme 21

Scheme 22

See also:
• TROUBLE CODE IDENTIFICATION
• CLEARING CODES
• CODE 14