1994 MAZDA MX-5 light

ENGINE TUNE-UP - TIMING LIGHT - 45UOFX422 GND Irnr Air Cleaner Element Inspection 1. Check the air cleaner element for excessive dirt and for oil and damage. Caution Cleaning the element with compressed air will re- duce the element's ability to filter the air. Don't use compressed air to clean the element. 2. Replace the element if necessary. ADJUSTMENT Preparation 1. Warm up the engine to normal operating temperature. 2. Turn all electric loads OFF. Headlight switch Blower switch Rear window defroster switch 3. Connect the SST to the data link connector. 4. Connect a timing light to the engine. 5. Connect a tachometer to the data link connector terminal IG- as shown. Ignition Timing 1. Perform Preparation. (Refer to above.) 2. Verify that the idle speed is within the specification; if not, adjust it. Idle speed 4 (Neutral): 800-900 (850 + 50) rpm [MT] (P range): 750-850 (800 & 50) rpm [AT] 3. Set switch A to position 1. 4. Set test switch to SELF TEST. 5. If the SST is not used, connect a jumper wire between the TEN terminal and the GND terminal of the data link connector. 6. Verify that the idle speed is within the specification. ldle speed (Ground the terminal TEN): 650-975 rpm 7. Verify that the timing mark (white) on the crankshaft pulley and the mark on the timing belt cover are aligned. lgnition timing: BTDC 9"-11" (10" & lo) Gartner Banana

ON-BOARD DIAGNOSIS SYSTEM Principle of Code Cycle Diagnostic trouble codes are determined as shown below. 1. Code cycle break The time between diagnostic trouble code cycles is 4.0 seconds (the time the lamp is off). 1 CYCLE DIAGNOSTIC I I TROUBLE CODE, CYCLE BREAK I JUU I I C-----------l 4.0 SEC. 2. Second digit of diagnostic trouble code (ones position) The digit in the ones position of the diagnostic trouble code represents the number of times the buzzer sounds 0.4 second during one cycle. I 1 1 CYCLE DIAGNOSTIC DIAGNOSTIC ON TROUBLE CODE I TROUBLE 1 2 3 CYCLE BREAK CODE: 03 UICCl4 4.0 4.0 4.0 SEC. SEC. SEC. 3. First digit of diagnostic trouble code (tens position) The digit in the tens position of the diagnostic trouble code represents the number of times the buzzer is on 1.2 seconds during one cycle. It should also be noted that the light goes off for 1.6 seconds between the long and short pulses of the buzzer. r 1 CYCLE DIAGNOSTIC DIAGNOSTIC . TROUBLE CODE TROUBLE L 12 CODE: 22 - FIRST DIGIT SECOND DIGIT Gartner Banana

ON-BOARD DIAGNOSIS SYSTEM SWITCH MONITOR FUNCTION Inspection Procedure POWERTRAIN CONTROL MODULE (ENGINE) NEUTRAL SWITCH CLUTCH SWITCH 1 STOPLIGHT SWITCH HEADLIGHT SWITCH REAR WINDOW DEFROSTER SWITCH PARKINEUTRAL SWITCH IDLE SWITCH (IN THROTTLE POSITION SENSOR) BLOWER SWITCH AIR CONDITIONING SENSOR I ' SYSTEM MONITOR LAMP (SELF-DIAGNOSIS 1 Clutch switch (MT) 1 Pedal released I Pedal depressed I In gear I Switch Self-Diagnosis Checker (Monitor lamp) I Liaht ON Liaht OFF . . I I I - I Idle switch (in throttle position sensor) I Pedal depressed I Pedal released 1 Remark ParWneutral switch (AT) I L, S, D and R range I N and P range I I I Stoplight switch (MT) Pedal depressed I Pedal released - I Neutral I Clutch pedal released Neutral switch (MT) - In gear I I Blower switch Headlight switch OFF Blower motor position: "medium" "high" or "super hiah" position I I ON 1. Connect the SST to the data link connector as shown. 2. Turn the ignition switch ON. Check if the monitor lamp il- luminates when each switch is made to function as de- scribed below. If any switch remains activated, the monitor lamp will be illuminated. 3. Connect the SST to the data link connector as shown. 4. Turn the ignition switch to ON (engine off). Check if the monitor lamp illuminates when each switch is adjusted as described above. 45UOFX-173 OFF 1 Air conditioning sensor Rear window defroster switch - ON ON OFF OFF Fan speed control: Low position - Gartner Banana

F ON-BOARD DIAGNOSIS SYSTEM Procedure - Set conditions to deactivate each switch a All accessories OFF a Transmission in neutral a All pedals released Verify that monitor lamp does not illuminate Neutral and Clutch switches (MT) Parklneutral switch (AT) Depress clutch pedal Verify that monitor lamp does not illuminate Return transmission to neutral NO PC: a Neutral or clutch switch malfunction (Refer to F-146) a Open circuit in related wire harness a Powertrain control module (engine) terminal 1V malfunction (Refer to page F-146) - Shift transmission into gear Verify that monitor lamp illuminates with clutch pedal is re- leased PC: a Clutch switch malfunction (Refer to page F-157) 35UOFX-046 I ParWneutral switch OK Shift into P or N range Check each switch and related wire harness a Clutch and Neutral switch :Refer to page F-I57 a Idle switch (in throttle position sensor) :Refer to page F-154 a Stoplight switch :Refer to Section T Headlight switch :Refer to Section T 1 Check each switch as described I I NO - ldle switch (in throttle position sensor) a Blower switch :Refer to Section T a Air conditioning sensor :Refer to Section U a Rear window defroster switch :Refer to Section T a ParWneutral switch :Refer to Section K YES PC: a ParWneutral switch malfunction (Refer to Section K) a Open or short circuit in related wire harness a PCME terminal 1 V voltage incorrect (Refer to page F-I 46) PCME malfunction - Shift transmission into L, S, D, or P range Check that monitor lamp illuminates 35UOFX-06 NO + YES I 1 I ldle switch OK I L I PC: Throttle position sensor malfunction (Refer to page F-144) a Short circuit in wire harness from throttle position sensor to PCME a PCME terminal 1 N voltage incorrect (Refer to page F-145) a PCME malfunction - Depress accelerator pedal and check that monitor lamp illu- minates f NO --c YES PC: a Throttle position sensor malfunction (Refer to page F-144) Open circuit in wire harness from throttle position sensor to PCME PCME terminal 2M voltage incorrect (Refer to page F-146) Release acceleration pedal and check that monitor lamp does not illuminate 2 YES I I Gartner Banana

ON-BOARD DIAGNOSIS SYSTEM Stoplight switch OK Release brake pedal Stoplight switch (MT) Headlight switch PC: Stoplight switch malfunction (Refer to Section T) 0 Open circuit in wire harness from stoplight switch to powertrain control module (engine) Powertrain control module (engine) terminal 10 malfunction (Refer to page F-145) Headlight switch OK Turn OFF headlight switch I I NO ---c L, Blower switch YES Depress brake pedal and verify that monitor lamp illuminates PC: Headlight switch malfunction (Refer to section T) Open circuit in wire harness from headlight switch to powertrain control module (engine) Powertrain control module (engine) terminal 1 U malfunction (Refer to page F-146) Turn ON headlight switch Verify that monitor lamp illuminates Verify that monitor lamp illuminates NO - I YES YES Blower switch OK Turn OFF blower switch Air conditioning sensor PC: Blower switch malfunction (Refer to section T) 0 Open circuit in wire harness from blower switch to powertrain control module (engine) 0 Powertrain control module (engine) terminal IS malfunction (Refer to page F-146) 1 I YES I ' Set fan speed control to low position Turn air conditioning sensor ON, and verify that monitor lamp illuminates PC: Air conditioning sensor malfunction (Refer to Section U) Blower switch malfunction Open circuit in wire harness from air conditioning sensor to blower switch Powertrain control module (engine) terminal 1Q malfunction (Refer to page F-146) NO' 4 Air conditioning sensor OK Turn air conditioning sensor and blower switch OFF Rear window defroster switch Turn rear window defroster switch ON Is monitor lamp illuminated? NO PC: Rear window defroster switch malfunction (Refer to Section T) Open circuit in wire harness (Rear window defroster switch - PCME) PCME terminal 2L voltage incorrect (Refer to page F-146) PCME malfunction YES Turn rear window defroster switch OFF u Rear window defroster switch OK Gartner Banana

IDLE SPEED CONTROL SYSTEM PREPARATION SST I 'L 49 801 9 9AO For inspection of air System valve Selector BAC VALVE System Operation Air valve - Perform this inspection when the engine is cold. (Engine coolant temperature below 20°C {68OF).) 1. Connect a tachometer to the data link connector terminal IG-. When using an externally powered timing light and/ or tachometer connect it to the power connector (Blue: 1 -pin). Caution Grounding the power connector terminal (Blue: 1-pin) will burn out the 20A wiper fuse. 2. Connect the SST and set the TEST SW to "SELF TEST" or connect data link connector terminals TEN and GND with a jumper wire. 3. Verify that the engine speed gradually decreases as the engine warms up. 4. Remove the SST or the jumper wire. Gartner Banana

PRESSURE REGULATOR CONTROL SYSTEM PRESSURE REGULATOR CONTROL SYSTEM DATA LINK CONNECTOR - CLUTCH SWITCH (MT) (TEN TERMINAL) PARKINEUTRAL SWITCH (PCMT) (AT) THROTTLE POSITION SENSOR L 1 ,,,, INTAKE AIR TEMPERATURE 1 SENSOR (IN MASS AIRFLOW SENSOR) -;- ENGINE COOLANT TEMPERATURE SENSOR PRC SOLENOID VALVE CRANKSHAFT POSITION SENSOR PRESSURE REGULATOR PCME I Above 90°C {194OF} ( Above 70°C {158'F} I Throttle valve closed throttle position or no load condition I Approx. 150 1 I Operating condition Coolant temperature I Intake air temperature I Engine condition I I To prevent percolation of the fuel during hot restart idle, vacuum to the pressure regulator is momentarily cut, and the fuel injection pressure is increased to slightly more than 284 kPa (2.9 kgf/cm2, 41.2 psi}. Operating time (sec) Gartner Banana

F POSITIVE CRANKCASE VENTILATION (PCV) SYSTEM POSITIVE CRANKCASE VENTILATION (PCV) SYSTEM DESCRIPTION The PCV valve is operated by the intake manifold vacuum. 4 When the engine is running at idle the PCV valve is opened slightly and a small amount of blow by gas is drawn into the intake manifold to be burned. At higher engine speeds the PCV valve is opened further, allowing a larger amount of blow by gas to be drawn into the intake manifold. VENTILATION I PCV VALVE Inspection 1. Warm up the engine to the normal operating tempera- ture and run it at idle. 2. Disconnect the PCV valve together with the ventilation hose from the cylinder head cover. 3. Block the PCV valve opening. 4. Verify that vacuum is felt. 5. Remove the PCV valve. 6. Blow through the valve from port A and verify that air comes out of port B. 7. Blow through the valve from port B and verify that no air comes out of port A. 8. Replace the PCV valve if necessary. Gartner Banana