Engine Control System: Other Mazda MX-5 NC

Not Using the WDS or Equivalent

Note. The PCM terminal voltage can vary with the conditions when measuring and changes due to aged deterioration on the vehicle, causing false diagnosis. Therefore determine comprehensively where the malfunction occurs among the input systems, output systems, and the PCM.

Scheme 64

PCM TERMINALS VOLTAGE SPECIFICATION TABLE

PCM Terminals

1. 2A (+)-Negative battery terminal (-)

Oscilloscope Setting

1. 5 V/DIV (Y), 1 ms/DIV (X), DC range

Vehicle Condition

1. Idle (Accelerator pedal released)

Scheme 65

1. 2B (+) - Negative battery terminal (-)

1. 5 V/DIV (Y), 1 ms/DIV (X), DC range

1. Idle (Accelerator pedal released)

Scheme 66

1. 2C (+)-Negative battery terminal (-)

1. 2 V/DIV (Y), 0.1 s/DIV (X), DC range

1. Idle after warm-up

Scheme 67

1. 2E (+)-Negative battery terminal (-)

1. 2.5 V/DIV (Y), 1 ms/DIV (X), DC range

1. Idle after warm-up

Scheme 68

1. 2O (+)-Negative battery terminal (-)

1. 1 V/DIV (Y), 10 ms/DIV (X), DC range

1. Vehicle speed is 10 km/h {6.2 mph}

Scheme 69

1. 2S (+) - Negative battery terminal (-)

1. 2 V/DIV (Y), 50 ms/DIV (X), DC range

1. Idle after warm-up

Scheme 70

1. 2W (+) - Negative battery terminal (-)

1. 2 V/DIV (Y), 10 ms/DIV (X), DC range

1. Idle after warm-up

Scheme 71

1. 2AI (+) - Negative battery terminal (-)

1. 0.5 V/DIV (Y), 1 ms/DIV (X), DC range

1. Idle after warm-up

Scheme 72

1. 2AJ (+) - Negative battery terminal (-)

1. 2 V/DIV (Y), 1 ms/DIV (X), DC range

1. Idle after warm-up

Scheme 73

1. IGT1 (No.1): 2BA (+) - Negative battery terminal (-)
2. IGT2 (No.2): 2AW (+) - Negative battery terminal (-)
3. IGT3 (No.3): 2AX (+) - Negative battery terminal (-)
4. IGT4 (No.4): 2AT (+) - Negative battery terminal (-)

1. 2 V/DIV (Y), 50 ms/DIV (X), DC range

1. Idle after warm-up

Scheme 74

1. Fuel Injection No.1: 2BB (+) - Negative battery terminal (-)
2. Fuel Injection No.2: 2BC (+) - Negative battery terminal (-)
3. Fuel Injection No.3: 2BD (+) - Negative battery terminal (-)
4. Fuel Injection No.4: 2AZ (+) - Negative battery terminal (-)

1. 10 V/DIV (Y), 10 ms/DIV (X), DC range

1. Idle after warm-up

Scheme 75

1. 2BG (+) - Negative battery terminal (-)

1. 5 V/DIV (Y), 50 ms/DIV (X), DC range

1. Idle after warm-up (no load)

Scheme 76

Using the WDS or Equivalent

Note. PIDs for the following parts are not available on this model. Go to the appropriate part inspection reference. CMP sensor Main relay

1. Connect the SST (WDS or equivalent) to the DLC-2.
2. Turn the ignition switch to ON position.
3. Measure the PID value. If PID value is not within the specification, follow the instructions in "Inspection item (s)" column. NOTE: The PID/DATA MONITOR function monitors the calculated value of the input/output signals in the PCM. Therefore, an output device malfunction is not directly indicated as a malfunction of the monitored value for the output device. If a monitored value of an output device is out of specification, inspect the monitored value of the input device related to the output control. For input/output signals except those of the monitoring items, use a voltmeter to measure the PCM terminal voltage. The simulation items that are used in the ENGINE CONTROL SYSTEM OPERATION INSPECTION are as follows. ACCS, ALTF, EVAPCP, FAN1, FAN2, FAN3, FP, FUELPW1, GENVDSD, HTR11, HTR12, IMTV, INJ_1, INJ_2, INJ_3, INJ_4, SEGRP, test, VT DUTY1 Wt

PID/DATA Monitor Table (Reference)

PID/DATA MONITOR TABLE

PCM CONFIGURATION [LF]

1. Connect the WDS or equivalent to the DLC-2.
2. Set up the WDS or equivalent (including the vehicle recognition).
3. Select "Module Programming".
4. Select "Programmable Module Installation".
5. Select "PCM" and perform procedures according to directions on the WDS or equivalent screen. NOTE: If the PCM is replaced with a new one, the PCM stores DTC P0602 and illuminates the MIL even though no malfunction is detected. This means the PCM has not been configured yet.
6. Retrieve DTC's by the WDS or equivalent, then verify that there in no DTC present. If DTC is present, perform applicable DTC inspection. (See «DTC TABLE [LF]»(ref-244449-S40344338372006092400000) .)

Open Circuit

1. If there is no continuity, there is an open circuit. Repair or replace the wiring harness. Neutral switch terminal 2A and PCM terminal 1X Neutral switch terminal 1A and body ground

Short Circuit

1. If there is continuity, there is a short circuit. Repair or replace the wiring harness. Neutral switch terminal 2A and body ground

1. If there is no continuity, there is an open circuit. Repair or replace the wiring harness. CPP switch terminal B and PCM terminal 1D CPP switch terminal D and body ground

1. If there is continuity, there is a short circuit. Repair or replace the wiring harness. CPP switch terminal B and body ground

1. If there is no continuity, there is an open circuit. Repair or replace the wiring harness. PSP switch terminal A and PCM terminal 2T

1. If there is continuity, there is a short circuit. Repair or replace the wiring harness. PSP switch terminal A and body ground

Scheme 77

Scheme 78

Scheme 79

Scheme 80

1. Remove the battery cover.
2. Disconnect the negative battery cable. (See «BATTERY REMOVAL/INSTALLATION [LF]»(ref-244448-S25513985422006092400000) .)
3. Drain the engine coolant from the radiator. (See «ENGINE COOLANT REPLACEMENT [LF]»(ref-244456-S02885124352006092400000) .)
4. Remove the service hole cover. Remove the suspension tower bar (joint), (right side) and (left side). (See «FRONT SUSPENSION TOWER BAR REMOVAL/INSTALLATION»(ref-244475-S20579544822006092400000) .) Remove the wiper arm. (See «WIPER ARM AND BLADE REMOVAL/INSTALLATION»(ref-244477-S04548950182006092400000) .) Remove the cowl grille. (See «COWL GRILLE REMOVAL/INSTALLATION»(ref-244478-S13431226702006092400000) .) Remove the side cowl grille. (See «SIDE COWL GRILLE REMOVAL/INSTALLATION»(ref-244478-S39487642132006092400000) .) Move the cooler pipe No.3 and heater pipe slightly out of the way. Remove the service hole cover. (See «EGR VALVE REMOVAL/INSTALLATION [LF]»(ref-244459-S41291996702006092400000) .)
5. Disconnect the heater hose and move the heater pipe slightly out of the way.
6. Disconnect the ECT sensor connector.
7. Remove the ECT sensor. NOTE: Put the double nut together and install the torque wrench. (See «TORQUE FORMULAS»(ref-244444-S39279561722006092400000) .)
8. Install in the reverse order of removal. ECT sensor tightening torque 10-14 N.m {1.1-1.4 kgf.m, 7.4-10.3 ft.lbf}

1. If there is no continuity, there is an open circuit. Repair or replace the wiring harness. ECT sensor terminal A and PCM terminal 2AH ECT sensor terminal B and PCM terminal 2AY

1. If there is continuity, there is a short circuit. Repair or replace the wiring harness. ECT sensor terminal A and power supply ECT sensor terminal A and body ground ECT sensor terminal B and power supply

1. If there is no continuity, there is an open circuit. Repair or replace the wiring harness. MAF/IAT sensor terminal D and PCM terminal 1 AT MAF/IAT sensor terminal E and PCM terminal 1 AR

1. If there is continuity, there is a short circuit. Repair or replace the wiring harness. MAF/IAT sensor terminal E and power supply MAF/IAT sensor terminal D and power supply MAF/IAT sensor terminal D and body ground

1. If there is no continuity, the circuit is open. Repair or replace the wiring harness. CKP sensor terminal A and PCM terminal 2AB CKP sensor terminal B and PCM terminal 2W CKP sensor terminal C and PCM terminal 2AQ

1. If there is continuity, the circuit is shorted. Repair or replace the wiring harness. CKP sensor terminal A and power supply CKP sensor terminal B and power supply CKP sensor terminal B and body ground CKP sensor terminal C and body ground

1. If there is no continuity, the circuit is open. Repair or replace the wiring harness. CMP sensor terminal A and PCM terminal 2P CMP sensor terminal B and PCM terminal 2S CMP sensor terminal C and PCM terminal 2AM

1. If there is continuity, the circuit is shorted. Repair or replace the wiring harness. I CMP sensor terminal A and power supply CMP sensor terminal B and power supply CMP sensor terminal B and body ground CMP sensor terminal C and body ground

1. If there is no continuity in the following wiring harnesses, there is an open circuit. Repair or replace the wiring harness. Throttle body terminal C and PCM terminal 2AP Throttle body terminal D and PCM terminal 2AL Throttle body terminal E and PCM terminal 2AO Throttle body terminal F and PCM terminal 2AK

1. If there is continuity in the following wiring harnesses, there is a short circuit. Repair or replace the wiring harness. Throttle body terminal C and power supply Throttle body terminal D and body ground Throttle body terminal D and power supply Throttle body terminal E and body ground Throttle body terminal F and body ground Throttle body terminal F and power supply

1. If there is no continuity in the following wiring harnesses, there is an open circuit. Repair or replace the wiring harness. APP sensor terminal A and PCM terminal 1AJ APP sensor terminal B and PCM terminal 1AV APP sensor terminal C and PCM terminal 1AP APP sensor terminal D and PCM terminal 1AL APP sensor terminal E and PCM terminal 1AS APP sensor terminal F and PCM terminal 1AO

1. If there is continuity in the following wiring harnesses, there is a short circuit. Repair or replace the wiring harness. APP sensor terminal A and body ground APP sensor terminal B and power supply APP sensor terminal C and body ground APP sensor terminal C and power supply APP sensor terminal D and body ground APP sensor terminal E and power supply APP sensor terminal F and body ground APP sensor terminal F and power supply

1. If there is no continuity, there is an open circuit, Repair or replace the wiring harness. MAF/IAT sensor terminal A and PCM main relay MAF/IAT sensor terminal B and PCM terminal 1P MAF/IAT sensor terminal C and PCM terminal 1AK

Scheme 81

1. If there is continuity, there is a short circuit. Repair or replace the wiring harness. MAF/IAT sensor terminal A and body ground MAF/IAT sensor terminal B and power supply MAF/IAT sensor terminal C and power supply MAF/IAT sensor terminal C and body ground

INTAKE MAF (G/S) AND ENGINE LOAD CALCULATED VALUE SPECIFICATION

Scheme 82

1. Remove the battery cover.
2. Disconnect the negative battery cable. (See «BATTERY REMOVAL/INSTALLATION [LF]»(ref-244448-S25513985422006092400000) .)
3. Install the SST to the front HO2S.
4. Remove the front HO2S.
5. Install in the reverse order of removal. Front HO2S tightening torque 29-49 N.m {3.0-4.9 kgf.m, 22-35 ft.lbf}

1. If there is no continuity in the following wiring harnesses, there is an open circuit. Repair or replace the wiring harness. Front HO2S terminal A and PCM terminal 2AD Front HO2S terminal B and PCM terminal 2Z Front HO2S terminal C ignition relay Front HO2S terminal D and PCM terminal 2BG

1. If there is continuity in the following wiring harnesses, there is a short circuit. Repair or replace the wiring harness. Front HO2S terminal A and power supply Front HO2S terminal A and body ground Front HO2S terminal B and power supply Front HO2S terminal B and body ground Front HO2S terminal C and body ground Front HO2S terminal D and power supply Front HO2S terminal D and body ground

1. If there is no continuity, there is an open circuit. Repair or replace the wiring harness. Rear HO2S terminal A and PCM terminal 2Q Rear HO2S terminal B and PCM terminal 2BH Rear HO2S terminal C and ignition relay Rear HO2S terminal D and PCM terminal 2BE

1. If there is continuity in the following wiring harnesses, there is a short circuit. Repair or replace the wiring harness. Rear HO2S terminal A and power supply Rear HO2S terminal A and body ground Rear HO2S terminal B and power supply Rear HO2S terminal B and body ground Rear HO2S terminal C and body ground Rear HO2S terminal D and power supply Rear HO2S terminal D and body ground

1. If there is no continuity, there is an open circuit. Repair or replace the wiring harness. MAP/boost air temperature sensor terminal A and PCM terminal 2AV MAP/boost air temperature sensor terminal C and PCM terminal 2AU MAP/boost air temperature sensor terminal D and PCM terminal 2AG

1. If there is continuity, there is a short circuit. Repair or replace the wiring harness. MAP/boost air temperature sensor terminal A and power supply. MAP/boost air temperature sensor terminal C and body ground. MAP/boost air temperature sensor terminal D and power supply. MAP/boost air temperature sensor terminal D and body ground.

1. If there is no continuity, there is an open circuit. Repair or replace the wiring harness. KS terminal A and PCM terminal 2U KS terminal B and PCM terminal 2V

1. If there is continuity, there is a short circuit. Repair or replace the wiring harness. KS terminal A and power supply KS terminal A and body ground KS terminal B and power supply KS terminal B and body ground