1994 MAZDA MX-5 clutch

F TROUBLESHOOTING GUIDE DESCRIPTION I Blower fan operates but cool air not expelled ITROUBLESHOOTING HINTS] Open or short circuit in wiring harness NC relay malfunction 34 Air conditioning sensor malfunction Magnetic clutch malfunction PCME malfunction AIC DOES NOT WORK INSPECTION ;round terminal B at NC relay with jumper wire Yes tnd check if condenser fan operates when ignition ;witch is turned ON #C RELAY I ;round terminal B at PCME 1 J terminal with jump- Yes ,r wire and check if condenser fan operates when gnition switch is turned ON - No :heck if Air conditioning sensor is OK Yes Section U ACTION 30 to next step 30 to A/C system Troubleshooting Section U 30 to next step qepair wire between PCME and A/C relay page F-7 Try known good PCME page F-144 ;heck Air conditioning sensor and wiring Section U 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

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

COOLANT FAN CONTROL COOLANT FAN CONTROL OUTLINE The PCME controls the coolant fan and the condenser fan to provide more efficient fan control. This 4 improves the performance reliability and stability during idling of an engine. The coolant fan is normal when it start to operate with the data link connector TEN terminal grounded and the accerelator pedal is depressed (Ignition switch ON). IGNITION SWITCH OFF CONDENSER FAN MOTOR PCME RELAY I& MAGNETIC CLUTCH I COOLANT FAN RELAY Q COOLANT FAN MOTOR Gartner Banana

CONTROL SYSTEM STRUCTURAL VIEW i 1. Powertrain control module (engine) 6. Heated oxygen sensor Inspection . . . . . . . . . . . . . . . . . . page F-144 Inspection . . . . . . . . . . . . . . . . . . page F-156 Removal / Installation . . . . . . . . page F-143 Replacement . . . . . . . . . . . . . . . page F-156 2. Crankshaft position sensor 7. Main relay Removal . . . . . . . . . . . . . . . . . . . page F-153 Inspection . . . . . . . . . . . . . . . . . . page F-156 lnspection . . . . . . . . . . . . . . . . . . page F-153 8. Clutch switch Installation . . . . . . . . . . . . . . . . . page F-153 Inspection . . . . . . . . . . . . . . . . . . page F-157 3. Mass airflow sensor Replacement . . . . . . . . . . . . . . . page F-157 System inspection . . . . . . . . . . . page F-152 9. Neutral switch Inspection . . . . . . . . . . . . . . . . . . page F-152 Inspection . , . . . . . . . . . . . . . . . . page F-157 4. Engine coolant temperature sensor Replacement . . . . . . . . . . . . . . . page F-157 Removal . . . . . . . . . . . . . . . . . . . page F-154 10. Steering pressure sensor Inspection . . . . . . . . . . . . . . . . . . page F-154 Inspection . . . . . . . . . . . . . . . . . . page F-158 Installation . . . , . . . . . . . . . . . . . page F-154 Replacement . . . . . . . . . . . . . . . page F-158 5. Throttle position sensor -,' Inspection . . . . . . . . . . . . . . . . . . page F-155 Adjustment . . . . . . . . . . . . . . . . . page F-155 Replacement . . . . . . . . . . . . . . . page F-156 Gartner Banana

F CONTROL SYSTEM B+: Battery positive voltage Connection to 1 Test condition 1 Voltage I Remark I -- EGR solenoid valvi Idle B+ Blower switch -- EGR solenoid valve (vacuum) :vent) Initial acceleration* Blower switch at mid, high or su- per high position Blower switch OFF or low Headlight switch Neutral or clutch switch (MT) B+ Idle ParWneutral switch (AT) Ground (Injector) Ground (Output) Ground (PCME) Approx. OV - Approx. 12V B+ Headlights ON (Tail, parking, low beamfhigh beam) Headlights OFF Neutral position or clutch pedal de- pressed Other conditions Ground (Input) Crankshaft position (SGT-signal) Ignition switch ON N or fJ range Other conditions Constant Constant Constant -. Mass airflow sensor .. . . EGR function sensor I while running Approx. 0-5v Initial acceleration* Approx, 2V OV ov B+ Constant Ignition switch ON Idle Crankshaft position sensor (SGC-signal) Data link connector (TEN terminal) Igniter I I I Vre f I lanition switch ON 1 4.5-5.9.' 1 - B+ - OV B+ OV OV OV Ignition switch ON Idle - - - OV OV or 5V ADD~OX. 2V - - Ignition switch ON Idle System Selector test switch at "02 MONITOR" System Selector test switch at "SELF-TEST" Ignition switch ON Idle lanition switch ON I . . I I 1 Ignition switch ON I Below 1 .OV I I - - . . Below 1 .OV Below 1 .OV ear window defrost- er relay Throttle position sensor Heated oxygen sensor - OV or 5V Approx. 1.5V B+ ov Below 0.5V Approx. 1 V Approx. 1 .OV - - - " Rear window defroster switch OFF Rear window defroster switch ON Accelerator pedal released Accelerator ~edal fullv de~ressed Mass airflow sensor B+ Below 1 .OV 0.1-1 .o 3.14.5 Intake air temperature sensor Engine coolant tem- perature sensor lgnition switch ON lgnition switch ON Ignition switch ON Idle ireen and red lamps flash At 200C {680Fj Engine coolant temperature 20°C {680F) After warm-up Below 1 .OV 1 .O-2.0 - Approx. 2.5V Approx. 2.5V Approx. 0.4V Built in mass airflow lgnition switch ON Gartner Banana

F CONTROL SYSTEM B+: Battery positive voltage Abnormal voltage Possible cause Terminal 1 v Connection to Neutral switch malfunction (Refer to page F-157) Clutch switch malfunction (Refer to page F-156) Short circuit in wiring from PCME terminal 1 V to neutral or clutch switch Neutral switch malfunction (Refer to page F-157) 0 Clutch switch malfunction (Refer to page F-156) 0 Open circuit in wiring from PCME terminal 1 V to neutral or clutch switch Poor connection at PCME connector 0 ParWneutral switch malfunction (Refer to section K) 0 Short circuit in wiring from parWneutral switch to PCME terminal 1V 0 ParWneutral switch malfunction (Refer to section K) 0 Open circuit in wiring from parWneutral switch to PCME terminal 1 V Always OV Neutral switchlClutch switch (MT) Always B+ Always OV ParWneutral switch (AT) Always B+ Poor contact at ground terminal 0 Open circuit in wiring from PCME to ground Sround More than OV Crankshaft position sensor (SGT-signal) Always OV or approx. 5V Always below 2V or 4V Refer to Code No.03 troubleshooting (Refer to page F-84) Refer to code No.08 Troubleshooting (Refer to page F-86) 0 Short circuit in wiring from PCME terminal 2H to data link connector terminal TEN Mass airflow sensor Always OV Data link connector (Terminal TEN) 0 Open circuit in wiring from PCME terminal 2H data link connector terminal TEN 0 Open circuit in wiring from data link connector terminal GND to around Always B+ Igniter EGR function sensor Always OV Always approx. OV or approx. 5v Refer to Code No.01 troubleshooting (Refer to paae F-83) 0 Refer to Code No.16 Troubleshooting (Refer to page F-89) 0 Short circuit in wiring from PCME terminal 2K tothrottle position sensor, PCME, or mass airflow sensor Poor connection at PCME connector PCME malfunction Vre f Always OV lllumination light ON when rear window defroster switch ON Open or short circuit in wiring from rear window de- froster switch to PCME terminal 2L Always below 1 .ov Rear window defroster switch Open circuit in wiring from ignition switch to rear win- dow defroster switch Rear window defroster switch malfunction (Refer to section T) lllumination light never ON Open circuit in wiring from PCME terminal 2M to throttle position sensor 0 Open circuit in wiring from PCME terminal 2K to throttle position sensor 0 Open circuit in wiring from PCME terminal 20 to throttle position sensor Always constant Throttle position sensor Alwavs above 1V 0 Throttle position sensor misadjustment Refer to Code No.15 troubleshooting (Refer to page F-88) OV after warm-up Heated oxygen sensor Always approx, 1V after warm-up 0 Refer to Code No.17 troubleshooting (Refer to page F-90) Refer to Code No.08 troubleshooting (Refer to page F-86) Mass airflow sensor Always OV or approx. 5V Gartner Banana