1994 MAZDA MX-5 clutch

Before beginning any service procedure. refer to section T of this manual for air bag system service warnings and audio antitheft system alarm conditions . FUEL AND EMISSION CONTROL SYSTEMS INDEX ............................ F- 2 ......................... OUTLINE F- 5 .............. SYSTEM DIAGRAM F- 5 VACUUM HOSE ROUTING DIAGRAM ...................... F- 6 WIRING DIAGRAM ............... F- 7 SPECIFICATIONS ............... F- 8 COMPONENT DESCRIPTIONS ... F- 9 ....... TROUBLESHOOTING GUIDE F- 11 ENGINE CONTROL OPERATION CHART ........................ F- 11 RELATIONSHIP CHART .......... F- 12 USING THIS SECTION ........... F- 13 DIAGNOSTIC INDEX ............. F- 15 SYMPTOM TROUBLESHOOTING . F- 17 PREPARATION ................... F- 75 ............. BASIC INSPECTION F- 75 .................. ADJUSTMENT F- 76 ON-BOARD DIAGNOSIS SYSTEM . . F- 78 DESCRIPTION .................. F- 78 PREPARATION .................. F- 79 DIAGNOSTIC TROUBLE CODE NUMBER ...................... F- 79 ... SWITCH MONITOR FUNCTION F- 95 INTAKE AIR SYSTEM .............. F- 98 COMPONENTS .................. F- 98 SYSTEM OPERATION ............ F-100 THROTTLE BODY ............... F-101 INTAKE MANIFOLD .............. F-102 ACCELERATOR PEDAL AND CABLE ........................ F-103 IDLE SPEED CONTROL SYSTEM ... F-104 DESCRI PTlON .................. F-104 PREPARATION .................. F-105 BAC VALVE ..................... F-105 IDLE AIR CONTROL VALVE ....... F-106 FUEL SYSTEM .................... F-107 DESCRIPTION .................. F-107 PREPARATION .................. F-108 SYSTEM OPERATION ............ F-109 FUEL TANK ..................... F-111 FUEL FILTER .................... F-113 FUEL PUMP .................... F-114 FUEL PUMP RELAY .............. F-117 PRESSURE REGULATOR ........ F-118 FUEL INJECTOR ................ F-119 PRESSURE REGULATOR CONTROL SYSTEM ......................... F-122 PRC SOLENOID VALVE .......... F-123 EXHAUST GAS RECIRCULATION (EGR) ........................... F-124 PREPARATION .................. F-124 .................. DESCRIPTION F-124 SYSTEM OPERATION F-125 ............ EGR SOLENOID VALVE (VACUUM) F-125 EGR SOLENOID VALVE (VENT) ... F-126 ......... EGR FUNCTION SENSOR F-126 ........... EGR CONTROL VALVE F-127 ................ EXHAUST SYSTEM F-128 .................. COMPONENTS F-128 OUTLINE OF EMISSION CONTROL ......................... SYSTEM F-129 ............. STRUCTURAL VIEW F-129 POSITIVE CRANKCASE VENTILATION ................... (PCV) SYSTEM F-130 ' DESCRIPTION .................. F-I ..................... PCV VALVE F-1 ..... FUEL EVAPORATIVE SYSTEM F- .................. DESCRIPTION F- ....... PURGE SOLENOID VALVE F- ........ TWO-WAY CHECK VALVE F- ...... THREE-WAY CHECK VALVE F- ............. FUEL VAPOR VALVE F- .......... CHARCOAL CANISTER F- CATALYTIC CONVERTER SYSTEM . F- .................. DESCRIPTION F- .......... THREE-WAY CATALYST F- AIC CUT-OFF CONTROL SYSTEM . . F- .................. DESCRIPTION F- ........... SYSTEM INSPECTION F- ...................... A/c RELAY F-1 36 ..... DECHOKE CONTROL SYSTEM F-137 .................. DESCRIPTION F-137 ......... COOLANT FAN CONTROL F-138 ....................... OUTLINE F-138 .................. COOLANT FAN F-139 ............... CONDENSER FAN F-139 ........... SYSTEM INSPECTION F-140 ........... COOLANT FAN RELAY F-140 ........ CONDENSER FAN RELAY F-140 ............... CONTROL SYSTEM F-141 .................. PREPARATION F-141 ............. STRUCTURAL VIEW F-142 POWERTRAIN CONTROL MODULE .............. (ENGINE) (PCME) F-143 ........ MASS AIRFLOW SENSOR F-152 CRANKSHAFT POSITION SENSOR F-153 ENGINE COOLANT TEMPERATURE ...................... SENSOR F-154 THROTTLE POSITION SENSOR . . F-154 HEATED OXYGEN SENSOR ...... F-156 MAIN RELAY .................... F-157 ............... CLUTCH SWITCH F-157 NEUTRAL SWITCH .............. F-157 STEERING PRESSURE SENSOR . F-158 45UOFX-001 Gartner Banana

INDEX 10. Charcoal canister lnspection . . . . . . . . . . . . . . . . . . page F-133 11. Powertrain control module (engine) Removal / Installation . . . . . . . . page F-143 lnspection . . . . . . . . . . . . . . . . . . page F-143 12. Crankshaft position sensor Removal . . . . . . . . . . . . . . . . . . . page F-153 lnspection . . . . . . . . . . . . . . . . . . page F-153 lnstallation . . . . . . . . . . . . . . . . . page F-153 13. Mass airflow sensor System inspection . . . . . . . . . . . page F-152 lnspection . . . . . . . . . . . . . . . . . . page F-152 14. Engine coolant temperature sensor Removal . . . . . . . . . . . . . . . . . . . page F-154 lnspection . . . . . . . . . . . . . . . . . . page F-154 Installation . . . . . . . . . . . . . . . . . page F-154 15. Throttle position sensor lnspection . . . . . . . . . . . . . . . . . . page F-154 Adjustment . . . . . . . . . . . . . . . . . page F-155 Replacement . . . . . . . . . . . . . . . page F-156 16. Heated oxygen sensor lnspection . . . . . . . . . . . . . . . . . . page F-156 Replacement . . . . . . . . . . . . . . . page F-156 17. Main relay lnspection . . . . . . . . . . . . . . . . . . page F-157 18. Clutch switch (MT) lnspection . . . . . . . . . . . . . . . . . . page F-157 Replacement . . . . . . . . . . . . . . . page F-157 19. Neutral switch (MT) lnspection . . . . . . . . . . . . . . . . . . page F-157 Replacement . . . . . . . . . . . . . . . page F-158 20. Steering pressure sensor lnspection . . . . . . . . . . . . . . . . . . page F-158 Replacement . . . . . . . . . . . . . . . page F-158 21. Fuel pump relay lnspection . . . . . . . . . . . . . . . . . . page F-117 Replacement . . . . . . . . . . . . . . . page F-117 22. PRC solenoid valve lnspection (On-vehicle) . . . . . . page F-123 lnspection . . . . . . . . . . . . . . . . . . page F-123 23. EGR solenoid valve (Vacuum) lnspection . . . . . . . . . . . . . . . . . . page F-125 24. EGR solenoid valve (Vent) lnspection . . . . . . . . . . . . . . . . . . page F-126 25. EGR function sensor lnspection . . . . . . . . . . . . . . . . . . page F-126 26. EGR control valve lnspection . . . . . . . . . . . . . . . . . . page F-127 Replacement . . . . . . . . . . . . . . . page F-127 27. NC relay lnspection . . . . . . . . . . . . . . . . . . page F-136 28. Coolant fan relay lnspection . . . . . . . . . . . . . . . . . . page F-140 29. Condenser fan relay lnspection . . . . . . . . . . . . . . . . . . page F-140 Gartner Banana

PURGE SOLENOID VALVE 7* AlC RELAY COOLANT FAN RELAY CONDENSER FAN RELAY STARTER STEERING PRESSURE SENSOR AIR CONDITIONING SENSOR ... CHECK VALVE FUEL-FILTER (HIGH-PRESSURE SIDE) / CRANKSHAFT POSITION SENSOR HEATED OXYGEN SENSOR ltT=I THREE-WAY CATALYST - REAR WINDOW DEFROSTER SWITCH COMBINATION SrmCH BLOWER SWlTCH STOPLIGHT SWITCH (MT) CLUTCH SWITCH (MT) - NEUTRALSWrrCH (MT) TEN TERMINAL PARWEUTRAL SWITCH (AT) VEHICLE SPEED SENSOR ENGINE COOLAMTEMPERATURE SENSOR EGR SOLENOID VALVE WEM) EGR SOLENOID VALVE (VACUUM) - w TO PCME Gartner Banana

OUTLINE F COMPONENT DESCRIPTIONS Component Air cleaner housing Air valve Remark Function Filters air entering throttle body When cold, supplies bypass air into dynamicchamber w Engine speed increased to shorten warm-up period Thermowax type Barometric absolute pressure sensor Detects barometric absolute pressure; sends signal to powertrain control module (engine) 3uilt-in PCME Charcoal canister Clutch switch (MT) Stores gas tank fumes while engine stopped Detects in-gear condition: sends signal to powertrain control module (engine) --- ~witch OFF when clutch pedal released Crankshaft position sen- sor Detects No.1 cylinder TDC; sends signal to powertrain control module (engine) Detects crank angle at 180" intervals; sends signal to powertrain control module (engine) Data link connector Concentrated service connector Concentrated terminals are: 1. CIS on-board diagnosis terminal 2. Initial set terminal 3. Fuel pump check terminal Dynamic chamber Interconnects all cylinders Detects coolant temperature; sends signal to powertrain control module (engine) Recircurates oortion of exhaust aas Engine coolant temperature sensor EGR control valve lnstalled in EGR control valve EGR function sensor Detects EGR control valve operating position; send sig- nal to PCME EGR solenoid valve (vent) Controls vacuum to EGR control valve (vent side) Controlled by duty signal from PCME . - EGR solenoid valve (vac- Controls vacuum to EGR control valve (vacuum side) 0 Controlled by duty signal from PCME uum) Fuel filter Filters particles from fuel Injects fuel into intake port Fuel injector Controlled by signals from powertrain control module (engine) High-ohmic injector 0 Sinale port injector nozzle Fuel pump Provides fuel to fuel injectors 0 operates while engine running lnstalled in fuel tank Fuel pump relay Voltage for fuel pump while engine running Fuel vapor valve Prevents fuel from entering canister during vehicle roll over Heated oxygen sensor Detects oxygen concentration; sends signal to power- train control module (engine) 0 Zirconia ceramic and platinum coating ldle air control valve Controls bypass air amount Controlled by duty signal from powertrain control module (engine) Controls idle-up lnstalled in throttle position sensor lnstalled in ignition coil ldle switch Igniter Detects idle condition; sends signal to PCME Receives spark signal from powertrain control module (engine) and generates high voltage in ignition coil Detects high voltage ignition; sends substitute ignition signal to powertrain control module (engine) Ignition switch (START position) Sends engine cranking signal to powertrain control mod- ule (engine) Intake air temperature sensor Detects intake air temperature: sends signal to powertrain control module (engine) Installed in mass airflow sensor Main relay Supplies electric current to fuel injectors, powertrain control module (engine), etc. Gartner Banana

TROUBLESHOOTING GUIDE RELATIONSHIP CHART Fuel injector TEN Terminal (Data link connector) Ignition Switch (Start Position) Steering Pressure Sensor X X X X X X X X X X X X X X X xoo Blower Switch Headlight Switch Stoplight Switch Neutral and Clutch Switches (MT) Parklneutral switch (AT) Air Conditioning Sensor Idle Switch Throttle I BDL) Position Sensor I Sensor (NO) Barometric Absolute Pres- sure Sensor IGF Signal Heated Oxygen Sensor Engine Coolant Temperature Sensor Sensor Mass Air- flow Sensor Intake Air Temperature Sensor Crankshaft SGTSignal Position Sensor SGC-Signal Gartner Banana

TROUBLESHOOTING GUIDE F 24 Overloaded ) Low intake air amount Throttle valve not oDen fully LACK OF POWER ESCRIPmH - TEP - 1 - 2 : Performance poor under load Reduced maximum speed :heck factors other than engine Clutch slipping as Section H Brake dragging Section P Low tire pressure as Section Q Unrecommended tire size Section Q ;heck if throttle valve wide open throttles when lepressing accelerator fully rROUBLESHOOTlNG HINTS] Factors other than engine malfunction O AirlFuel mixture too lean or too rich Clutch slipping Fuel line pressure low or high Brake dragging Insufficient fuel injection Low tire pressure @ Poor ignition Unrecommended tire size 8 Low engine compression >heck if "00 is displayed on Self-Diagnosis Check- !r with ignition switch ON page F-79 :heck switches for correct operation with Self- Diagnosis Checker Monitor Lamp and ignition switch ON as page F-95 SELECT SW A YSTEM SELECT 1 - Yes Yes Clogged intake air system - INSPECTION I - C 0 0 0 0 - c C - ( E -- I I i I I No - Yes No - Yes - No ACTION %to next step 20 to next step Sheck if accelerator cable is correctly installed page F-103 3 If OK, check throttle body @r page F-101 3 If not OK, install accelerator cable correctly page F-103 - 30 to next step Diagnostic Trouble Code No. displayed Check for cause (Refer to specified check sequence) page F-81 "88" flashes Check PCME terminal 1 E voltage @r page F-145 Specification: Battery positive voltage (Ignition switch ON) o If OK, replace PCME page F-143 O If not OK, check wiring between PCME and Self-Diagno- sis Checker E+T page F-7 Go to next step -- Lamp not ONlOFF with specified switch Check for cause (Refer to specified check sequence) page F-96 Lamp always ON Check wiring between PCME terminal 1 D and Self-Diag- nosis Checker @r page F-7 Gartner Banana

TROUBLESHOOTING GUIDE TROUBLESHOOTING HINTS] D Factors other than engine malfunction Clutch slipping Brake dragging Low tire pressure Unrecommended tire size 25 O AirIFuel mixture too lean or too rich Fuel line pressure low or high Insufficient fuel injection @ Poor ignition 6 Low engine compression POOR ACCELERATION Overloaded D Low intake air amount Throttle valve not open fully Clogged intake air system )ESCRIPTION I Performance poor while accelerating INSPECTION :heck factors other than engine Clutch slipping Section H D Brake dragging Section P t Low tire pressure Section Q D Unrecommended tire size Section Q :heck if throttle valve wide open throttles when jepressing accelerator fully Check if "00" is displayed on Self-Diagnosis Check- er with ignition switch ON page F-79 Check switches for correct operation with Self- Diagnosis Checker Monitor Lamp and ignition switch ON page F-95 SELECT SW A SYSTEM SELECT 1 - Yes - No Yes - No - Yes - No Yes - No ACTION Go to next step Repair Go to next step Check if accelerator cable is correctly installed * page 0 If OK, check throttle body ce Page 0 If not OK, install accelerator cable correctly page Go to next step -- Diagnostic Trouble Code No. displayed Check for cause (Refer to specified check sequenc US page "88" flashes Check PCME terminal 1 E voltage Us Page Specification: Battery positive voltage (Ignition switch ON) 0 If OK, replace PCME * Page 9 If not OK, check wiring between PCME and Self- sis Checker * Page Go to next step Lamp not ONlOFF with specified switch Check for cause (Refer to specified check sequenc * Paw Lamp always ON Check wiring between PCME terminal 1 D and Self nosis Checker * Page ! F-103 ! F-101 I F-103 :e) r F-81 ! F-145 I F-143 Diagno- ! F-7 :e) ! F-96 -Diag- ! F-7 Gartner Banana

TROUBLESHOOTING GUIDE F POOR FUEL ECONOMY I [TROUBLESHOOTING HINTS] Nhile fuel consumption is drastically increased during city driving, short-run operation, stop and go driving, extended winterwarm- ~p periods, etc., as opposed to "trip" mileage, an attempt should be made to determine these factors when confronted with "poor mileage" conditions. However, since the operator is not always at fault, the following is offered. 3 Operator depressing accelerator more than usual due to O Alcohol blended fuel used low engine power @ High vehicle load Poor ignition Low tire pressure Low intake air amount Unrecommended tire used Electric spark advance control malfunction Brake dragging Clutch slipping @ Fuel cut control malfunction Exhaust component restricted @ High idle speed AirIFuel mixture too rich High fuel line pressure INSPECTION Check factors other than engine Low tire pressure Section Q Unrecommended tire used @zT Section Q Clutch slipping Section H Brake dragging Section P Exhaust component restricted @zT page F-128 ACTION - Yes Go to next step Repair Check if air hoses are connected correctly @zT page F-99 Yes - No Go to next step Repair @zT page F-99 Check if air cleaner element is clean page F-76 Yes - No Go to next step Replace page 699 Check if "00" is displayed on Self-Diagnosis Check- er with ignition switch ON @zT page F-79 Yes Go to next step SELECT SW A SYSTEM SELECT 1 Diagnostic Trouble Code No. displayed Check for cause (Refer to specified check sequence) page F-81 "88" flashes Check PCME terminal 1 E voltage US page F-145 Specification: Battery positive voltage (Ignition switch ON) 6 If OK, replace PCME page F-143 6 If not OK, check wiring between PCME and Self-Diagno- sis Checker page F-7 Check switches for correct operation with Self- Diagnosis Checker Monitor Lamp and ignition switch ON page F-95 SELECT SW A Yes Go to next step ~~p Lamp not ONIOFF with specified switch Check for cause (Refer to specified check sequence) @zT page F-96 Lamp always ON Check wiring between PCME terminal 1 F and Self-Diag- nosis Checker us page F-7 Gartner Banana