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Home >> Mazda >> 2021 >> MX-5 Miata Club, Automatic Trans >> Repair and Diagnosis >> Engine Performance >> Engine Control Systems >> Pcm Inspection >> Without Using the M-MDS
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Without Using the M-MDS

NOTE:
  • Because the PCM uses a waterproof connector, the inspection for the voltage/wave pattern cannot be performed. The following values are for reference.

Terminal voltage table (Reference) 

G12184593Courtesy of MAZDA MOTORS CORP.
Terminal Signal Connected to Test condition Voltage (V) inspection item
1A (1) CAN_2H CAN system related modules Because this terminal is for CAN, integrity determination by terminal voltage is not possible.
  • Related wiring harness
1B (1) CAN_2L CAN system related modules Because this terminal is for CAN, integrity determination by terminal voltage is not possible.
  • Related wiring harness
1C -  - - - -
1D -  - - - -
1E Constant voltage (Vref) CKP sensor Ignition switched ON (engine off) Approx. 5.0
  • Related wiring harness
1F CKP CKP sensor (See CKP signal .)
  • CKP sensor
  • Related wiring harness
1G - - - - -
1H - - - - -
1I - - - - -
1J Constant voltage (Vref) MAP sensor Ignition switched ON (engine off) Approx. 5.0
  • Related wiring harness
1K Constant voltage (Vref) Fuel pressure sensor Ignition switched ON (engine off) Approx. 5.0
  • Related wiring harness
1L Constant voltage (Vref) TP sensor No. 1, TP sensor No. 2 Ignition switched ON (engine off) Approx. 5.0
  • Related wiring harness
1M A/F A/F sensor Idle (after warm up) Approx. 3.99
  • A/F sensor
  • Related wiring harness
1N GND Sensor shield Under any condition Below 1.0
  • Related wiring harness
1O TP (No. 1) TP sensor No. 1 Ignition switched ON (engine off) Accelerator pedal released Below 1.0
  • TP sensor No. 1
  • Related wiring harness
Accelerator pedal depressed Approx. 4.61
1P - - - - -
1Q IAT (No. 2) IAT sensor No. 2 Ignition switched ON (engine off) IAT 0°C {32°F} Approx. 5.9
  • IAT sensor No. 2
  • Related wiring harness
IAT 20°C {68°F} Approx. 2.5
IAT 40°C {104°F} Approx. 0.323
IAT 60°C {140°F} Approx. 0.0893
1R GND TP sensor No. 1, TP sensor No. 2 Under any condition Below 1.0
  • Related wiring harness
1S A/F A/F sensor Idle (after warm up): 0 mA
  • A/F sensor
  • Related wiring harness
1T A/F A/F sensor Idle (after warm up) Approx. 4.12
  • A/F sensor
  • Related wiring harness
1U GND Sensor shield Under any condition Below 1.0
  • Related wiring harness
1V TP (No. 2) TP sensor No. 2 Ignition switched ON (engine off) Accelerator pedal released Approx. 4.31
  • TP sensor No. 2
  • Related wiring harness
Accelerator pedal depressed Below 1.0
1W Fuel pressure Fuel pressure sensor Idle (ECT 80°C{176°F}) Approx. 1.4
  • Fuel pressure sensor
  • Related wiring harness
1X MAP MAP sensor Ignition switched ON (engine off) Approx. 5.02
  • MAP sensor
  • Related wiring harness
Idle (after warm up) Approx. 1.80
Racing (Engine speed: 2, 000 RPM) Approx. 1.18
1Y Knocking (+) KS Ignition switched ON (engine off) (Use digital type voltmeter, because measurement voltage will be detected less than true voltage when using analog type voltmeter) Approx. 2.44
  • KS
  • Related wiring harness
1Z Knocking (-) KS Ignition switched ON (engine off) (Use digital type voltmeter, because measurement voltage will be detected less than true voltage when using analog type voltmeter) Below 1.0
  • KS
  • Related wiring harness
1AA - - - - -
1AB GND ECT sensor Ignition switched ON (engine off) Below 1.0
  • Related wiring harness
1AC - - - - -
1AD Electric variable valve timing driver (diagnostic) Electric variable valve timing driver (See ELECTRIC VARIABLE VALVE TIMING DRIVER (DIAGNOSTIC) SIGNAL .)
  • Electric variable valve timing motor/driver
  • Related wiring harness
1AE Ion (No. 2) Ion sensor No. 2 Idle (after warm up) Approx. 4.44
  • Ion sensor No. 2
  • Related wiring harness
1AF Ion (No. 4) Ion sensor No. 4 Idle (after warm up) Approx. 4.44
  • Ion sensor No. 4
  • Related wiring harness
1AG Generator output voltage Generator (See GENERATOR OUTPUT VOLTAGE .)
  • Generator
  • Related wiring harness
1AH ECT ECT sensor Ignition switched ON (engine off) ECT 20°C
{68°F}		 Approx. 3.10
  • ECT sensor
  • Related wiring harness
ECT 40°C
{104°F}		 Approx. 2.16
ECT 60°C
{140°F}		 Approx. 1.40
ECT 80°C
{176°F}		 Approx. 0.87
ECT 100°C
{212°F}		 Approx. 0.54
1AI GND Intake CMP sensor, exhaust CMP sensor Under any condition Below 1.0
  • Related wiring harness
1AJ - - - - -
1AK Ion (No. 3) Ion sensor No. 3 Idle (after warm up) Approx. 4.44
  • Ion sensor No. 3
  • Related wiring harness
1AL Ion (No. 1) Ion sensor No. 1 Idle (after warm up) Approx. 4.44
  • Ion sensor No. 1
  • Related wiring harness
1AM - - - - -
1AN - - - - -
1AO - - - - -
1AP GND CKP sensor Ignition switched ON (engine off) Below 1.0
  • Related wiring harness
1AQ - - - - -
1AR - - - - -
1AS - - - - -
1AT GND Sensor shield Ignition switched ON (engine off) Below 1.0
  • Related wiring harness
1AU - - - - -
1AV - - - - -
1AW Purge control Purge solenoid valve (See PURGE CONTROL .)
  • Purge solenoid valve
  • Related wiring harness
1AX - - - - -
1AY - - - - -
1AZ (2) Back-up light Back-up light switch Shift lever is at R position Below 1.0
  • Back-up light switch
  • Related wiring harness
Shift lever is not at R position B+
1BA - - - - -
1BB - - - - -
1BC IGT1 Ignition coil No. 1 (See IGT1, IGT2, IGT3, IGT4 control .)
  • Ignition coil No. 1
  • Related wiring harness
1BD - - - - -
1BE Oil pressure Oil pressure switch Ignition switched ON (engine off) Below 1.0
  • Oil pressure switch
  • Related wiring harness
Idle (after warm up) B+
1BF (2) Neutral position Neutral switch Shift lever is at neutral position Below 1.0
  • Neutral switch No. 1
  • Related wiring harness
Shift lever is not at neutral position B+
1BG - - - - -
1BH GND MAP sensor, IAT sensor No. 2, fuel pressure sensor Under any condition Below 1.0
  • Related wiring harness
1BI IGT2 Ignition coil No. 2 (See IGT1, IGT2, IGT3, IGT4 control .)
  • Ignition coil No. 2
  • Related wiring harness
1BJ - - - - -
1BK - - - - -
1BL - - - - -
1BM Electric variable valve timing motor (rotation pulse) Electric variable valve timing motor (See ELECTRIC VARIABLE VALVE TIMING MOTOR (ROTATION PULSE) SIGNAL .)
  • Electric variable valve timing motor
  • Related wiring harness
1BN Electric variable valve timing motor (rotation direction) Electric variable valve timing motor (See ELECTRIC VARIABLE VALVE TIMING MOTOR (ROTATION DIRECTION) SIGNAL .)
  • Electric variable valve timing motor
  • Related wiring harness
1BO IGT3 Ignition coil No. 3 (See IGT1, IGT2, IGT3, IGT4 control .)
  • Ignition coil No. 3
  • Related wiring harness
1BP Generator field coil control Generator (See GENERATOR FIELD COIL CONTROL SIGNAL .)
  • Generator
  • Related wiring harness
1BQ - - - - -
1BR GND Sensor shield Ignition switched ON (engine off) Below 1.0
  • Related wiring harness
1BS - - - - -
1BT Intake CMP Intake CMP sensor (See INTAKE CMP SIGNAL .)
  • Intake CMP sensor
  • Related wiring harness
1BU IGT4 Ignition coil No. 4 (See IGT1, IGT2, IGT3, IGT4 control .)
  • Ignition coil No. 4
  • Related wiring harness
1BV Electric variable valve timing control Electric variable valve timing driver (See ELECTRIC VARIABLE VALVE TIMING CONTROL SIGNAL .)
  • Electric variable valve timing driver
  • Related wiring harness
1BW - - - - -
1BX - - - - -
1BY - - - - -
1BZ Exhaust CMP Exhaust CMP sensor (See EXHAUST CMP SIGNAL .)
  • Exhaust CMP sensor
  • Related wiring harness
1CA - - - - -
1CB A/F sensor heater control A/F sensor heater (See A/F sensor heater control signal .)
  • A/F sensor heater
  • Related wiring harness
1CC - - - - -
1CD - - - - -
1CE - - - - -
1CF - - - - -
1CG - - - - -
1CH - - - - -
1CI - - - - -
1CJ - - - - -
1CK Engine oil control Engine oil solenoid valve (See ENGINE OIL CONTROL SIGNAL .)
  • Engine oil solenoid valve
  • Related wiring harness
1CL - - - - -
1CM - - - - -
1CN - - - - -
1CO Hydraulic variable valve timing control OCV (See HYDRAULIC VARIABLE VALVE TIMING CONTROL SIGNAL .)
  • OCV
  • Related wiring harness
1CP - - - - -
1CQ Drive-by-wire control (+) Throttle valve actuator (See DRIVE-BY-WIRE CONTROL (+) SIGNAL .)
  • Throttle valve actuator
  • Related wiring harness
1CR Drive-by-wire control (-) Throttle valve actuator Idle (after warm up) Because the drive-by-wire control (-) terminal value varies depending on the vehicle, examination using only the ICQ terminal is not possible. When performing the inspection, perform it together with the ICR terminal.
  • Type A
    • B+
  • Type B
    • Approx. 0
  • Throttle valve actuator
  • Related wiring harness
1CS - - - - -
1CT - - - - -
1CU Fuel injection control (+) Fuel injector No. 3 (See FUEL INJECTION CONTROL (+) SIGNAL .)
  • Fuel injector No. 3
  • Related wiring harness
1CV Fuel injection control (-) Fuel injector No. 3 (See FUEL INJECTION CONTROL (-) SIGNAL .)
  • Fuel injector No. 3
  • Related wiring harness
1CW - - - - -
1CX - - - - -
1CY Fuel injection control (+) Fuel injector No. 2 (See FUEL INJECTION CONTROL (+) SIGNAL .)
  • Fuel injector No. 2
  • Related wiring harness
1CZ Fuel injection control (-) Fuel injector No. 2 (See FUEL INJECTION CONTROL (-) SIGNAL .)
  • Fuel injector No. 2
  • Related wiring harness
1DA - - - - -
1DB - - - - -
1DC Fuel injection control (+) Fuel injector No. 4 (See FUEL INJECTION CONTROL (+) SIGNAL .)
  • Fuel injector No. 4
  • Related wiring harness
1DD Fuel injection control (-) Fuel injector No. 4 (See FUEL INJECTION CONTROL (-) SIGNAL .)
  • Fuel injector No. 4
  • Related wiring harness
1DE - - - - -
1DF - - - - -
1DG Fuel injection control (+) Fuel injector No. 1 (See FUEL INJECTION CONTROL (+) SIGNAL .)
  • Fuel injector No. 1
  • Related wiring harness
1DH Fuel injection control (-) Fuel injector No. 1 (See FUEL INJECTION CONTROL (-) SIGNAL .)
  • Fuel injector No. 1
  • Related wiring harness
1DI High pressure fuel pump control (+) High pressure fuel pump (See HIGH PRESSURE FUEL PUMP CONTROL (+) SIGNAL .)
  • High pressure fuel pump
  • Related wiring harness
1DJ High pressure fuel pump control (-) High pressure fuel pump (See HIGH PRESSURE FUEL PUMP CONTROL (-) SIGNAL .)
  • High pressure fuel pump
  • Related wiring harness
2A Battery voltage Battery Ignition switched ON (engine off) B+
  • Battery
  • Related wiring harness
2B Main relay control Main relay Ignition switched ON (engine off) Below 1.0
  • Main relay
  • Related wiring harness
2C - - - - -
2D - - - - -
2E - - - - -
2F Ignition (IG1) IG1 relay Ignition switched ON (engine off) B+
  • IG1 relay
  • Related wiring harness
2G - - - - -
2H Starter cut-off control Starter relay, start stop unit Ignition switched ON (engine off) Selector lever position is not P or N position B+
  • Starter relay
  • Start stop unit
  • Related wiring harness
Selector lever position is P or N position Below 1.0
2I Cooling fan control Fan control module (See COOLING FAN CONTROL SIGNAL .)
  • Fan control module
  • Related wiring harness
2J - - - - -
2K - - - - -
2L - - - - -
2M - - - - -
2N - - - - -
2O - - - - -
2P Brake (No. 2) Brake switch (No. 2 signal) Brake pedal released Below 1.0
  • Brake switch (No. 2 signal)
  • Related wiring harness
Brake pedal depressed B+
2Q - - - - -
2R Ambient temperature Ambient temperature sensor Ignition switched ON (engine off) AAT 20°C
{68°F}		 Approx. 2.70
  • Ambient temperature sensor
  • Related wiring harness
AAT 30°C
{104°F}		 Approx. 1.80
2S CAN_H CAN system related modules Because this terminal is for CAN, integrity determination by terminal voltage is not possible.
  • Related wiring harness
2T CAN_L CAN system related modules Because this terminal is for CAN, integrity determination by terminal voltage is not possible.
  • Related wiring harness
2U - - - - -
2V - - - - -
2W - - - - -
2X Power brake unit vacuum Vacuum sensor 2 Idle (after warm up and no load) Brake pedal released Approx. 1.04
  • Vacuum sensor 2
  • Related wiring harness
2Y - - - - -
2Z - - - - -
2AA - - - - -
2AB Brake signal Brake switch (No. 1 signal) (4), brake light relay (5) Brake pedal released Below 1.0
  • Brake switch (No. 1 signal)
  • Related wiring harness
Brake pedal depressed B+
2AC - - - - -
2AD - - - - -
2AE - - - - -
2AF A/C cut-off control A/C relay A/C relay OFF B+
  • A/C relay
  • Related wiring harness
A/C relay ON Below 1.0
2AG - - - - -
2AH (2) CPP CPP switch, start stop unit Clutch pedal fully depressed Below 1.0
  • CPP switch
  • Start stop unit
  • Related wiring harness
Clutch pedal released B+
2AI GND MAF sensor, IAT sensor No. 1, refrigerant pressure sensor, ambient temperature sensor, fuel tank pressure sensor (3), vacuum sensor 2 Under any condition Below 1.0
  • Related wiring harness
2AJ(3) Fuel tank pressure Fuel tank pressure sensor Fuel tank pressure is 10 kPa {0.10 kgf/cm 2 , 1.5 psi} lower than barometric pressure. Approx. 1.2
  • Fuel tank pressure sensor
  • Related wiring harness
Fuel tank pressure is equal to barometric pressure. Approx. 2.6
Fuel tank pressure is 6 kPa {0.06 kgf/cm 2 , 0.9 psi} higher than barometric pressure. Approx. 3.7
2AK - - - - -
2AL (3) CV solenoid control CV solenoid valve Ignition switched ON (engine off) B+
  • CV solenoid valve
  • Related wiring harness
Idle (CV solenoid valve not operating) B+
Idle (CV solenoid valve operating) Below 1.0
2AM Cooling fan control Cooling fan relay Cooling fan operating Below 1.0
  • Cooling fan relay
  • Related wiring harness
Cooling fan not operating B+
2AN - - - - -
2AO Constant voltage (Vref) APP sensor No. 2 Ignition switched ON (engine off) Approx. 5.0
  • Related wiring harness
2AP - - - - -
2AQ - - - - -
2AR - - - - -
2AS - - - - -
2AT Constant voltage (Vref) MAF sensor, IAT sensor No. 1 Ignition switched ON (engine off) Approx. 5.0
  • Related wiring harness
2AU Constant voltage (Vref) Vacuum sensor 2, fuel tank pressure sensor Ignition switched ON (engine off) Approx. 5.0
  • Related wiring harness
2AV Refrigerant pressure Refrigerant pressure sensor Refrigerant pressure: 1.0 MPa {10 kgf/cm 2 , 145 psi} Approx. 1.58
  • Refrigerant pressure sensor
  • Related wiring harness
Refrigerant pressure: 1.1 MPa {11 kgf/cm 2 , 160 psi} Approx. 1.72
Refrigerant pressure: 1.2 MPa {12 kgf/cm 2 , 174 psi} Approx. 1.88
2AW Fuel pump control Fuel pump relay Ignition switched ON (engine off) B+
  • Fuel pump relay
  • Related wiring harness
Idle (after warm up) Below 1.0
2AX - - - - -
2AY - - - - -
2AZ Constant voltage (Vref) Refrigerant pressure sensor Ignition switched ON (engine off) Approx. 5.0
  • Related wiring harness
2BA Constant voltage (Vref) APP sensor No. 1 Ignition switched ON (engine off) Approx. 5.0
  • Related wiring harness
2BB APP (No. 2) APP sensor No. 2 Ignition switched ON (engine off) Accelerator pedal released Approx. 0.58
  • APP sensor No. 2
  • Related wiring harness
Accelerator pedal depressed Approx. 2.30
2BC - - - - -
2BD Selector lever position (1) TCM, start stop unit Selector lever position is not P or N position B+
  • TCM
  • Start stop unit
  • Related wiring harness
Selector lever position is P or N position Below 1.0
Starter interlock(2) Starter interlock switch, start stop unit Clutch pedal fully depressed Below 1.0
  • Starter interlock switch
  • Start stop unit
  • Related wiring harness
Clutch pedal released B+
2BE Intake air MAF sensor, IAT sensor No. 1 Because this terminal is for SENT signal, integrity determination by terminal voltage is not possible.
  • MAF sensor, IAT sensor No. 1
  • Related wiring harness
2BF - - - - -
2BG GND APP sensor No. 2 Under any condition Below 1.0
  • Related wiring harness
2BH GND APP sensor No. 1 Under any condition Below 1.0
  • Related wiring harness
2BI - - - - -
2BJ HO2S heater control HO2S heater (See HO2S HEATER CONTROL SIGNAL .)
  • HO2S heater
  • Related wiring harness
2BK HO2S (+) HO2S Idle (after warm up) Approx. 2.31
  • HO2S
  • Related wiring harness
2BL HO2S (-) HO2S Idle (after warm up) Approx. 2.05
  • HO2S
  • Related wiring harness
2BM GND Sensor shield Ignition switched ON (engine off) Below 1.0
  • Related wiring harness
2BN APP (No. 1) APP sensor No. 1 Ignition switched ON (engine off) Accelerator pedal released Approx. 0.79
  • APP sensor No. 1
  • Related wiring harness
Accelerator pedal depressed Approx. 4.56
2BO Main power supply Main relay Ignition switched ON (engine off) B+
  • Main relay
  • Related wiring harness
2BP - - - - -
2BQ GND GND Ignition switched ON (engine off) Below 1.0
  • Related wiring harness
2BR Main power supply Main relay Ignition switched ON (engine off) B+
  • Main relay
  • Related wiring harness
2BS - - - - -
2BT GND GND Ignition switched ON (engine off) Below 1.0
  • Related wiring harness
(1) AT

(2) MT

(3) U.S.A. and CANADA specs.

(4) Without smart city brake support (SCBS)

(5) With smart city brake support (SCBS)
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