Engine Controls - Self Diagnostics - 2.4L: Overview Mitsubishi Eclipse III

TERMINAL IDENTIFICATION

TERMINAL IDENTIFICATION DIRECTORY

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Circuit Operation

1. The volume air flow sensor power is supplied from the MFI relay (terminal 4), and the ground is provided on the ECM (terminal 40 - M/T) or PCM (terminal 16 - A/T).
2. 5 volts power is applied to the volume air flow sensor output terminal (terminal 3) from the ECM (terminal 90 - M/T) or PCM (terminal 65 - A/T). The volume air flow sensor generates a pulse signal when the output terminal and ground are opened/closed (opened/short).

Technical Description

1. While the engine is running, the volume air flow sensor outputs a pulse signal which corresponds to the volume of air flow.
2. The ECM (M/T) or PCM (A/T) checks whether the frequency of the signal output by the volume air flow sensor while the engine is running is at or above the set value.
3. When the throttle position sensor output voltage is low, the ECM (M/T) or PCM (A/T) causes the power transistor to be "ON" to send an air flow sensor reset signal to the air flow sensor. In response to the reset signal, the air flow sensor resets the filter circuit and improves the ability of the air flow sensor to measure the amount of air in a small air intake region.

1. The volume air flow sensor power is supplied from the MFI relay (terminal 4), and the ground is provided on the ECM (terminal 40 - M/T) or PCM (terminal 16 - A/T).
2. 5 volts power is applied to the volume air flow sensor output terminal (terminal 3) from the ECM (terminal 90) (M/T) or PCM (terminal 65 - A/T). The volume air flow sensor generates a pulse signal when the output terminal and ground are opened/closed (opened/short).

1. While the engine is running, the volume air flow sensor outputs a pulse signal which corresponds to the volume air flow.
2. The ECM (M/T) or PCM (A/T) checks whether the frequency of this signal output by the volume air flow sensor while the engine is running is at or above the set value.

1. 5 volts power is supplied to the barometric pressure sensor power terminal (terminal 1) from the ECM (terminal 81 - M/T) or PCM (terminal 46 - A/T). The ground terminal (terminal 5) is grounded with ECM (terminal 40 - M/T) or PCM (terminal 16 - A/T).
2. A voltage that is proportional to the atmospheric pressure is sent to the ECM (terminal 85 - M/T) or PCM (terminal 55 - A/T) from the barometric pressure sensor output terminal (terminal 2).

1. The barometric pressure sensor outputs a voltage which corresponds to the barometric pressure.
2. The ECM (M/T) or PCM (A/T) checks whether this voltage is within a specified range.

1. 5 volts power is supplied to the barometric pressure sensor power terminal (terminal 1) from the ECM (terminal 81 - M/T) or PCM (terminal 46 - A/T). The ground terminal (terminal 5) is grounded with ECM (terminal 40 - M/T) or PCM (terminal 16 - A/T).
2. A voltage that is proportional to the atmospheric pressure is sent to the ECM (terminal 85 - M/T) or PCM (terminal 55 - A/T) from the barometric pressure sensor output terminal (terminal 2).

1. The barometric pressure sensor outputs a voltage which corresponds to the barometric pressure.
2. The ECM (M/T) or PCM (A/T) checks whether this voltage is within a specified range.

1. 5 volts power is supplied to the barometric pressure sensor power terminal (terminal 1) from the ECM (terminal 81 - M/T) or PCM (terminal 46 - A/T). The ground terminal (terminal 5) is grounded with ECM (terminal 40 - M/T) or PCM (terminal 16 - A/T).
2. A voltage that is proportional to the atmospheric pressure is sent to the ECM (terminal 85 - M/T) or PCM (terminal 55 - A/T) from the barometric pressure sensor output terminal (terminal 2).

1. The barometric pressure sensor outputs a voltage which corresponds to the barometric pressure.
2. The ECM (M/T) or PCM (A/T) checks whether this voltage is within a specified range.

1. Approximately 5 volts are applied to the intake air temperature sensor output terminal (terminal 6) from the ECM (terminal 72 - M/T) or PCM (terminal 64 - A/T) via the resistor in the ECM (M/T) or PCM (A/T). The ground terminal (terminal 5) is grounded with ECM (terminal 40 - M/T) or PCM (terminal 16 - A/T).
2. The intake air temperature sensor is a negative temperature coefficient type of resistor. When the intake air temperature rises, the resistance decreases.
3. The intake air temperature sensor output voltage increases when the resistance increases and decreases when the resistance decreases.

1. The intake air temperature sensor converts the intake air temperature to a voltage.
2. The ECM (M/T) or PCM (A/T) checks whether this voltage is within a specified range.

1. Approximately 5 volts are applied to the intake air temperature sensor output terminal (terminal 6) from the ECM (terminal 72 - M/T) or PCM (terminal 64 - A/T) via the resistor in the ECM (M/T) or PCM (A/T). The ground terminal (terminal 5) is grounded with ECM (terminal 40 - M/T) or PCM (terminal 16 - A/T).
2. The intake air temperature sensor is a negative temperature coefficient type of resistor. When the intake air temperature rises, the resistance decreases.
3. The intake air temperature sensor output voltage increases when the resistance increases and decreases when the resistance decreases.

1. The intake air temperature sensor converts the intake air temperature to a voltage.
2. The ECM (M/T) or PCM (A/T) checks whether this voltage is within a specified range.

1. Approximately 5 volts are supplied to the intake air temperature sensor output terminal (terminal 6) from the ECM (terminal 72 - M/T) or PCM (terminal 64 - A/T) via the resistor in the ECM (M/T) or PCM (A/T). The ground terminal (terminal 5) is grounded with ECM (terminal 40 - M/T) or PCM (terminal 16 - A/T).
2. The intake air temperature sensor is a negative temperature coefficient type of resistor. When the intake air temperature rises, the resistance decreases.
3. The intake air temperature sensor output voltage increases when the resistance increases and decreases when the resistance decreases.

1. The intake air temperature sensor converts the intake air temperature to a voltage.
2. The ECM (M/T) or PCM (A/T) checks whether this voltage is within a specified range.

1. 5 volts power is applied to the engine coolant temperature sensor output terminal (terminal 1) from the ECM (terminal 83 - M/T) or PCM (terminal 44 - A/T) via the resistor in the ECM (M/T) or PCM (A/T). The ground terminal (terminal 2) is grounded with ECM (terminal 92 - M/T) or (terminal 57 - A/T).
2. The engine coolant temperature sensor is a negative temperature coefficient type of resistor. It has the characteristic that when the engine coolant temperature rises, the resistance decreases.
3. The engine coolant temperature sensor output voltage increases when the resistance increases and decreases when the resistance decreases.

1. The engine coolant temperature sensor converts the engine coolant temperature to a voltage and outputs it.
2. The ECM (M/T) or PCM (A/T) checks whether the voltage is within a specified range.

1. 5 volts current is applied to the engine coolant temperature sensor output terminal (terminal 1) from the ECM (terminal 83 - M/T) or PCM (terminal 44 - A/T) via the resistor in the ECM (M/T) or PCM (A/T). The ground terminal (terminal 2) is grounded with ECM (terminal 92 - M/T) or (terminal 57 - A/T).
2. The engine coolant temperature sensor is a negative temperature coefficient type of resistor. It has the characteristic that when the engine coolant temperature rises, the resistance decreases.
3. The engine coolant temperature sensor output voltage increases when the resistance increases and decreases when the resistance decreases.

1. The engine coolant temperature sensor converts the engine coolant temperature to a voltage and outputs it.
2. The ECM (M/T) or PCM (A/T) checks whether this voltage is within a specified range.

1. 5 volts current is applied to the engine coolant temperature sensor output terminal (terminal 1) from the ECM (terminal 83 - M/T) or PCM (terminal 44 - A/T) via the resistor in the ECM (M/T) or PCM (A/T). The ground terminal (terminal 2) is grounded with ECM (terminal 92 - M/T) or (terminal 57 - A/T).
2. The engine coolant temperature sensor is a negative temperature coefficient type of resistor. It has the characteristic that when the engine coolant temperature rises, the resistance decreases.
3. The engine coolant temperature sensor output voltage increases when the resistance increases and decreases when the resistance decreases.

1. The engine coolant temperature sensor converts the engine coolant temperature to a voltage and outputs it.
2. The ECM (M/T) or PCM (A/T) checks whether the voltage is within a specified range.

1. A 5-volt power supply is applied to the throttle position sensor power terminal (terminal 3) from the ECM (terminal 81 - M/T) or PCM (terminal 46 - A/T).
2. The ground terminal (terminal 2) is grounded with ECM (terminal 92 - M/T) or PCM (terminal 57 - A/T).
3. When the throttle valve shaft is turned from the idle position to the fully opened position, the resistance between the throttle position sensor output terminal (terminal 3) and ground terminal will increase according to the rotation.

1. The throttle position sensor outputs voltage which corresponds to the throttle valve opening angle.
2. The ECM (M/T) or PCM (A/T) checks whether the voltage is within a specified range.

1. A 5-volt power supply is applied to the throttle position sensor power terminal (terminal 4) from the ECM (terminal 81 - M/T) or PCM (terminal 46 - A/T).
2. The ground terminal (terminal 1) is grounded with ECM (terminal 92 - M/T) or PCM (terminal 57 - A/T).
3. When the throttle valve shaft is turned from the idle position to the fully opened position, the resistance between the throttle position sensor output terminal (terminal 3) and ground terminal will increase according to the rotation.

1. The throttle position sensor outputs voltage which corresponds to the throttle valve opening angle.
2. The ECM (M/T) or PCM (A/T) checks whether the voltage is within a specified range. In addition, it checks that the voltage output does not become too high while the engine is idling.

1. A 5-volt power supply is applied to the throttle position sensor power terminal (terminal 4) from the ECM (terminal 81 - M/T) or PCM (terminal 46 - A/T).
2. The ground terminal (terminal 1) is grounded with ECM (terminal 92 - M/T) or PCM (terminal 57 - A/T).
3. When the throttle valve shaft is turned from the idle position to the fully opened position, the resistance between the throttle position sensor output terminal (terminal 3) and ground terminal will increase according to the rotation.

1. The throttle position sensor outputs voltage which corresponds to the throttle valve opening angle.
2. The ECM (M/T) or PCM (A/T) checks whether the voltage is within a specified range. In addition, it checks that the voltage output does not become too high while the engine is at idle.

1. 5 volts power is applied to the engine coolant temperature sensor output terminal (terminal 1) from the ECM (terminal 83 - M/T) or PCM (terminal 44 - A/T) via the resistor in the ECM (M/T) or PCM (A/T). The ground terminal (terminal 2) is grounded with ECM (terminal 92 - M/T) or (terminal 57 - A/T).
2. The engine coolant temperature sensor is a negative temperature coefficient type of resistor. It has the characteristic that when the engine coolant temperature rises, the resistance decreases.
3. The engine coolant temperature sensor output voltage increases when the resistance increases and decreases when the resistance decreases.

1. The engine coolant temperature sensor converts the engine coolant temperature to a voltage and outputs it.
2. The ECM (M/T) or PCM (A/T) checks whether this voltage is within a specified range.

The ECM (M/T) or PCM (A/T) checks the time for the engine coolant temperature to reach the judgement temperature.

1. A voltage corresponding to the oxygen concentration in the exhaust gas is sent to the ECM (terminal 76 -M/T) or PCM (terminal 71 - A/T) from the output terminal (terminal 4) of the heated oxygen sensor (front).
2. Terminal 2 of the heated oxygen sensor (front) is grounded with ECM (terminal 92 - M/T) or PCM (terminal 57 - A/T).

1. The heated oxygen sensor (front) detects the concentration of oxygen in the exhaust gas; it converts that data to voltage, and inputs the resulting signals to the ECM (M/T) or PCM (A/T).
2. When the heated oxygen sensor (front) begins to deteriorate, the heated oxygen sensor signal response becomes poor.
3. The ECM (M/T) or PCM (A/T) forcibly varies the air/fuel mixture to make it leaner and richer, and checks the response speed of the heated oxygen sensor (front). In addition, the ECM (M/T) or PCM (A/T) also checks for an open circuit in the heated oxygen sensor (front) output line.

1. A voltage corresponding to the oxygen concentration in the exhaust gas is sent to the ECM (terminal 76 - M/T) or PCM (terminal 71 - A/T) from the output terminal (terminal 4) of the heated oxygen sensor (front).
2. Terminal 2 of the heated oxygen sensor (front) is grounded with ECM (terminal 92 - M/T) or PCM (terminal 57 - A/T).

1. The heated oxygen sensor (front) detects the concentration of oxygen in the exhaust gas; it converts that data to voltage, and inputs the resulting signals to the ECM (M/T) or PCM (A/T).
2. When the heated oxygen sensor (front) begins to deteriorate, the heated oxygen sensor signal response becomes poor.
3. The ECM (M/T) or PCM (A/T) forcibly varies the air/fuel mixture to make it leaner and richer, and checks the response speed of the heated oxygen sensor (front). In addition, the ECM (M/T) or PCM (A/T) also checks for an open circuit in the heated oxygen sensor (front) output line.

1. A voltage corresponding to the oxygen concentration in the exhaust gas is sent to the ECM (terminal 76 - M/T) or PCM (terminal 71 - A/T) from the output terminal (terminal 4) of the heated oxygen sensor (front).
2. Terminal 2 of the heated oxygen sensor (front) is grounded with ECM (terminal 92 - M/T) or PCM (terminal 57 - A/T).

1. The ECM (M/T) or PCM (A/T) effects air/fuel ratio feedback control in accordance with the signals from the heated oxygen sensor (front).
2. If the heated oxygen sensor (front) has deteriorated, corrections will be made by the heated oxygen sensor (rear).
3. DTC P0134 becomes stored in memory if a failure is detected in the air/fuel ratio feedback control system.

1. Power is supplied from the MFI relay (terminal 4) to the heated oxygen sensor (front) heater.
2. The ECM (terminal 60 - M/T) or PCM (terminal 3 - A/T) controls continuity to the heated oxygen sensor (front) heater by turning the power transistor in the ECM (M/T) or PCM (A/T) "ON" and "OFF".

The ECM (M/T) or PCM (A/T) checks whether the heater current is within a specified range when the heater is energized.

1. A voltage corresponding to the oxygen concentration in the exhaust gas is sent to the ECM (terminal 75 - M/T) or PCM (terminal 73 - A/T) from the output terminal (terminal 3) of the heated oxygen sensor (rear).
2. Terminal 4 of the heated oxygen sensor (rear) is grounded with ECM (terminal 92 - M/T) or PCM (terminal 57 - A/T).

1. The output signal of the heated oxygen sensor (front) is compensated by the output signal of the heated oxygen sensor (rear).
2. The ECM (M/T) or PCM (A/T) checks for an open circuit in the heated oxygen sensor (rear) output line.

1. A voltage corresponding to the oxygen concentration in the exhaust gas is sent to the ECM (terminal 75 - M/T) or PCM (terminal 73 - A/T) from the output terminal (terminal 3) of the heated oxygen sensor (rear).
2. Terminal 4 of the heated oxygen sensor (rear) is grounded with ECM (terminal 92 - M/T) or PCM (terminal 57 - A/T).

1. The output signal of the heated oxygen sensor (front) is compensated by the output signal of the heated oxygen sensor (rear).
2. The ECM (M/T) or PCM (A/T) checks for an open circuit in the heated oxygen sensor (rear) output line.

1. A voltage corresponding to the oxygen concentration in the exhaust gas is sent to the ECM (terminal 75 - M/T) or PCM (terminal 73 - A/T) from the output terminal (terminal 3) of the heated oxygen sensor (rear).
2. Terminal 4 of the heated oxygen sensor (rear) is grounded with ECM (terminal 92 - M/T) or PCM (terminal 57 - A/T)

1. The output signal of the heated oxygen sensor (front) is compensated by the output signal of the heated oxygen sensor (rear).
2. The ECM (M/T) or PCM (A/T) checks for an open circuit in the heated oxygen sensor (rear) output line.

1. Power is supplied from the MFI relay (terminal 4) to the heated oxygen sensor (rear) heater.
2. The ECM (terminal 54) (M/T) or PCM (terminal 26) (A/T) controls continuity to the heated oxygen sensor (rear) heater by turning the power transistor in the ECM (M/T) or PCM (A/T) "ON" and "OFF".

1. The ECM (M/T) or PCM (A/T) checks whether the heater current is within a specified range when the heater is energized.

1. The injector power is supplied from the MFI relay (terminal 4).
2. The ECM (M/T) or PCM (A/T) controls the injector by turning the power transistor in the ECM (M/T) or PCM (A/T) "ON" and "OFF".

1. If a malfunction occurs in the fuel system, the fuel trim value becomes too large.
2. The ECM (M/T) or PCM (A/T) checks whether the fuel trim value is within a specified range.

1. The injector power is supplied from the MFI relay (terminal 4).
2. The ECM (M/T) or PCM (A/T) controls the injector by turning the power transistor in the ECM (M/T) or PCM (A/T) "ON" and "OFF".

1. If a malfunction occurs in the fuel system, the fuel trim value becomes too small.
2. The ECM (M/T) or PCM (A/T) checks whether the fuel trim value is within a specified range.

1. 5 volts are applied to the fuel temperature sensor output terminal (terminal 3) from the ECM (terminal 77 - M/T) or PCM (terminal 51 - A/T) via the resistor in the ECM (M/T) or PCM (A/T).
2. The fuel temperature sensor output voltage increases when the resistance increases and decreases when the resistance decreases. The ground terminal (terminal 1) is grounded to the vehicle body.

1. The fuel temperature sensor converts the fuel temperature to a voltage.
2. The ECM (M/T) or PCM (A/T) detects the fuel temperature in the fuel tank with this output voltage.

1. 5 volts are applied to the fuel temperature sensor output terminal (terminal 3) from the ECM (terminal 77 - M/T) or PCM (terminal 51 - A/T) via the resistor in the ECM (M/T) or PCM (A/T).
2. The fuel temperature sensor output voltage increases when the resistance increases and decreases when the resistance decreases. The ground terminal (terminal 1) is grounded to the vehicle body.

1. The fuel temperature sensor converts the fuel temperature to a voltage.
2. The ECM (M/T) or PCM (A/T) detects the fuel temperature in the fuel tank with this output voltage.

1. 5 volts are applied to the fuel temperature sensor output terminal (terminal 3) from the ECM (terminal 77 - M/T) or PCM (terminal 51 - A/T) via the resistor in the ECM (M/T) or PCM (A/T).
2. The fuel temperature sensor output voltage increases when the resistance increases and decreases when the resistance decreases. The ground terminal (terminal 1) is grounded to the vehicle body.

1. The fuel temperature sensor converts the fuel temperature to a voltage.
2. The ECM (M/T) or PCM (A/T) detects the fuel temperature in the fuel tank with this output voltage.

1. The injector power is supplied from the MFI relay (terminal 4).
2. The ECM (M/T) or PCM (A/T) controls the injector by turning the power transistor in the ECM (M/T) or PCM (A/T) "ON" and "OFF".

1. The amount of fuel injected by the injector is controlled by the amount of continuity time the coil is grounded by the ECM (M/T) or PCM (A/T).
2. A surge voltage is generated when the injectors are driven and the current flowing to the injector coil is shut off.
3. The ECM (M/T) or PCM (A/T) checks this surge voltage.

1. The injector power is supplied from the MFI relay (terminal 4).
2. The ECM (M/T) or PCM (A/T) controls the injector by turning the power transistor in the ECM (M/T) or PCM (A/T) "ON" and "OFF".

1. If a misfire occurs while the engine is running, the engine speed changes for an instant.
2. The ECM (M/T) or PCM (A/T) checks for such changes in engine speed.

1. The injector power is supplied from the MFI relay (terminal 4).
2. The ECM (M/T) or PCM (A/T) controls the injector by turning the power transistor in the ECM (M/T) or PCM (A/T) "ON" and "OFF".

1. If a misfire occurs while the engine is running, the engine speed changes for an instant.
2. The ECM (M/T) or PCM (A/T) checks for such changes in the engine speed.

The knock sensor sends a signal voltage to the ECM (terminal 78 - M/T) or PCM (terminal 90 - A/T).

1. The knock sensor converts the vibration of the cylinder block into a voltage and outputs it. If there is a malfunction of the knock sensor, the voltage output will not change.
2. The ECM (M/T) or PCM (A/T) checks whether the voltage output changes.

1. The crankshaft position sensor power is supplied from the MFI relay (terminal 4).
2. Terminal 1 of the crankshaft position sensor is grounded with ECM (terminal 40 - M/T) or PCM (terminal 16 - A/T).
3. 5 volts are applied on the crankshaft position sensor output terminal (terminal 2) from the ECM (terminal 89 - M/T) or PCM (terminal 45 - A/T). The crankshaft position sensor generates a pulse signal when the output terminal is opened and grounded.

1. The crankshaft position sensor detects the crank angle (position) of each cylinder, and converts that data to pulse signals, which are then input to the ECM (M/T) or PCM (A/T).
2. When the engine is running, the crankshaft position sensor outputs a pulse signal.
3. The ECM (M/T) or PCM (A/T) checks whether the pulse signal is input while the engine is cranking.

1. The camshaft position sensor power is supplied from the MFI relay (terminal 4).
2. Terminal 1 of the camshaft position sensor is grounded with ECM (terminal 40 - M/T) or PCM (terminal 16 - A/T).
3. 5 volts are applied on the camshaft position sensor output terminal (terminal 2) from the ECM (terminal 88 - M/T) or PCM (terminal 56 - A/T). The camshaft position sensor generates a pulse signal when the output terminal is opened and grounded.

1. The camshaft position sensor functions to detect the top dead center position of the number 1 cylinder and to convert that data to pulse signals that are input to the ECM (M/T) or PCM (A/T).
2. When the engine is running, the camshaft position sensor outputs a pulse signal.
3. The ECM (M/T) or PCM (A/T) checks whether pulse signal is input while the engine is cranking.

1. When the EGR solenoid switches from "OFF" to "ON" while the engine is running, EGR gas flows.
2. The ECM (M/T) or PCM (A/T) checks how the EGR gas flow signal changes.

1. The EGR solenoid power is supplied from the MFI relay (terminal 4).
2. The ECM (M/T) or PCM (A/T) controls the EGR solenoid ground by turning the power transistor in the ECM (M/T) or PCM (A/T) "ON" and "OFF".

1. To judge if there is an open circuit in the EGR solenoid drive circuit, ECM (M/T) or PCM (A/T) measures the surge voltage of the EGR solenoid coil.
2. The ECM (M/T) or PCM (A/T) drives the EGR solenoid. After the solenoid is turned off, the ECM (M/T) or PCM (A/T) will check if the solenoid coil produces a surge voltage of 2 volts or more.

1. The signal from the rear heated oxygen sensor differs from the front heated oxygen sensor. That is because the catalytic converter purifies exhaust gas. When the catalytic converter has deteriorated, the signal from the front heated oxygen sensor becomes similar to the rear heated oxygen sensor.
2. The ECM (M/T) or PCM (A/T) compares the output of the front and rear heated oxygen sensor signals.

1. ECM (M/T) or PCM (A/T) detects stuck open evaporative emission purge solenoid valve and stuck closed evaporative emission ventilation solenoid valve by pressure change in fuel tank.
2. The state of the evaporative emission purge solenoid valve is judged by monitoring leak of evaporative emission control system.
3. The state of the evaporative emission ventilation solenoid valve is judged 20 seconds after end of monitoring leak of the evaporative emission control system, or of usual operation of evaporative emission purge solenoid from ON to OFF.

1. To judge if there is a leak in the fuel system, ECM (M/T) or PCM (A/T) measure the change of the pressure inside the fuel tank.
2. The ECM (M/T) or PCM (A/T) turns on the evaporative emission ventilation solenoid to shoot off the evaporative emission canister outlet port.
3. Then the evaporative emission purge solenoid is driven to set the fuel system into a negative pressure.
4. When the fuel system develops a vacuum of 0.29 psi (2 kPa), the evaporative emission purge solenoid is turned "OFF" and the fuel system vacuum is maintained at 0.29 psi (2 kPa).
5. The ECM (M/T) or PCM (A/T) determines if there is a leak in the fuel system by measuring the change of vacuum inside the fuel tank.
6. The test is stopped when fuel vapor pressure is judged as too high.

Overview of Troubleshooting

1. To determine the cause of DTC P0442, a performance test is needed. The performance test uses a mechanical vacuum gauge and scan tool set on the fuel tank differential pressure sensor (TANK PRES SNER 73). The mechanical gauge reading is used to verify scan tool reading. A comparison of the mechanical gauge to scan tool determines the problem in the system.
2. Prior to doing the performance test, several simple inspections are needed to exclude some possibilities of the symptom.

1. Power to the evaporative emission purge solenoid is supplied from the MFI relay (terminal 4).
2. The ECM (M/T) or PCM (A/T) controls ground the evaporative emission purge solenoid by turning the power transistor in the ECM (M/T) or PCM (A/T) "ON" and "OFF".

1. To judge if there is an open circuit in the evaporative emission purge solenoid drive circuit, ECM (M/T) or PCM (A/T) measures the surge voltage of the evaporative emission purge solenoid coil.
2. The ECM (M/T) or PCM (A/T) drives the evaporative emission purge solenoid. After the solenoid is turned off, the ECM (M/T) or PCM (A/T) will check if the solenoid coil produces a surge voltage of 2 volts or more.

1. The evaporative emission ventilation solenoid power is supplied from the MFI relay (terminal 4).
2. The ECM (M/T) or PCM (A/T) controls the evaporative emission ventilation solenoid ground by turning the power transistor in the ECM (M/T) or PCM (A/T) ON and OFF.

1. To judge if there is an open circuit in the evaporative emission ventilation solenoid drive circuit, ECM (M/T) or PCM (A/T) measures the surge voltage of the evaporative emission ventilation solenoid coil.
2. The ECM (M/T) or PCM (A/T) drives the evaporative emission ventilation solenoid for 30 milliseconds. After the solenoid is turned off, the ECM (M/T) or PCM (A/T) will check if the solenoid coil produces a surge voltage of 2 volts or more.

1. 5 volts are supplied to the power terminal of the fuel tank differential pressure sensor (terminal 3) from the ECM (terminal 81 - M/T) or PCM (terminal 46 - A/T). The ground terminal (terminal 2) is grounded with the ECM (terminal 92 - M/T) or PCM (terminal 57 - A/T).
2. A voltage proportional to the pressure in the fuel tank is sent from the output terminal of the fuel tank differential pressure sensor (terminal 1) to the ECM (terminal 61 - M/T) or PCM (terminal 92 - A/T).

1. To judge if the fuel tank differential pressure sensor is defective, the ECM (M/T) or PCM (A/T) monitors the fuel tank differential pressure sensor output voltage.
2. Based on the test conditions and judgement criteria, the ECM (M/T) or PCM (A/T) judges if the fuel tank differential pressure sensor output voltage is normal.

1. DTC P0451 can be set if any of the following conditions occur: Faulty fuel differential pressure sensor, related circuit, or ECM (M/T) or PCM (A/T).
2. To check a system blockage, do a performance test which uses a mechanical vacuum gauge and scan tool set on the fuel tank differential pressure sensor (TANK PRS SNSR73). The mechanical gauge reading is used to verify the reading from scan tool. A comparison of the mechanical gauge to scan tool determines the problem in the system.

1. 5 volts are supplied to the power terminal of the fuel tank differential pressure sensor (terminal 3) from the ECM (terminal 81 - M/T) or PCM (terminal 46 - A/T). The ground terminal (terminal 2) is grounded with the ECM (terminal 92 - M/T) or PCM (terminal 57 - A/T).
2. A voltage proportional to the pressure in the fuel tank is sent from the output terminal of the fuel tank differential pressure sensor (terminal 1) to the ECM (terminal 61 - M/T) or PCM (terminal 92 - A/T).

1. To judge if the fuel tank differential pressure sensor is defective, the ECM (M/T) or PCM (A/T) monitors the fuel tank differential pressure sensor output voltage.
2. Based on the test conditions and judgement criteria, the ECM (M/T) or PCM (A/T) judges if the fuel tank differential pressure sensor output voltage is normal.

1. The DTC P0452 can be set if any of the following conditions occur: Faulty fuel differential pressure sensor, related circuit, or ECM (M/T) or PCM (A/T).
2. To check a system blockage, do a performance test which uses a mechanical vacuum gauge and scan tool set on the fuel tank differential pressure sensor (TANK PRS SNSR73). The mechanical gauge reading is used to verify scan tool reading. A comparison of the mechanical gauge to scan tool determines the problem in the system.

1. 5 volts are supplied to the power terminal of the fuel tank differential pressure sensor (terminal 3) from the ECM (terminal 81 - M/T) or PCM (terminal 46 - A/T). The ground terminal (terminal 2) is grounded with the ECM (terminal 92 - M/T) or PCM (terminal 57 - A/T).
2. A voltage proportional to the pressure in the fuel tank is sent from the output terminal of the fuel tank differential pressure sensor (terminal 1) to the ECM (terminal 61 - M/T) or PCM (terminal 92 - A/T).

1. To judge if the fuel tank differential pressure sensor is defective, the ECM (M/T) or PCM (A/T) monitors the fuel tank differential pressure sensor output voltage.
2. Based on the test conditions and judgement criteria, the ECM (M/T) or PCM (A/T) judges if the fuel tank differential pressure sensor output voltage is normal.

1. The DTC P0453 can be set if any of the following conditions occur: Faulty fuel differential pressure sensor, related circuit, or ECM (M/T) or PCM (A/T).
2. To check a system blockage, do a performance test which uses a mechanical vacuum gauge and scan tool set on the fuel tank differential pressure sensor (TANK PRS SNSR73). The mechanical gauge reading is used to verify scan tool reading. A comparison of the mechanical gauge to scan tool determines the problem in the system.

1. To judge if there is a leak or clog in the fuel system, the ECM (M/T) or PCM (A/T) measures the change of the pressure inside the fuel tank.
2. The ECM (M/T) or PCM (A/T) turns on the evaporative emission system ventilation solenoid to shut off the evaporative emission canister outlet port.
3. Then the evaporative emission purge solenoid is driven to set the fuel system into a negative pressure.
4. When the fuel system develops a vacuum of 0.29 psi (2 kPa), the evaporative emission purge solenoid is turned "OFF" and the fuel system vacuum is maintained at 0.29 psi (2 kPa).
5. The ECM (M/T) or PCM (A/T) determines if there is a leak or clog in the fuel system by measuring the change of vacuum inside the fuel tank.
6. The test is stopped when fuel vapor pressure is judged to be too high.

1. To determine the cause of DTC P0455, a performance test is needed. The performance test uses a mechanical vacuum gauge and scan tool set on the fuel tank differential pressure sensor (TANK PRES SNER 73). The mechanical gauge reading is used to verify scan tool reading. A comparison of the mechanical gauge reading to scan tool reading determines the reading problem in the system.
2. Prior to doing the performance test, several simple inspections are needed to exclude some possibilities of the symptom.

1. To judge if there is a leak in the fuel system, ECM (M/T) or PCM (A/T) measures pressure changes in the fuel tank.
2. The ECM (M/T) or PCM (A/T) turns on the evaporative emission ventilation solenoid valve to shoot off the evaporative emission canister outlet port.
3. Then the evaporative emission purge solenoid valve is driven to set the fuel system into a negative pressure.
4. When the fuel system develops a vacuum of 0.29 psi (2 kPa), the evaporative emission purge solenoid valve is turned "OFF" and the fuel system vacuum is maintained at 0.29 psi (2 kPa).
5. The ECM (M/T) or PCM (A/T) determines if there is a leak in the fuel system by measuring the change of vacuum inside the fuel tank.
6. The test is stopped when fuel vapor pressure is judged to be too high.

1. To determine the cause of DTC P0456, a performance test is needed. The performance test uses a mechanical vacuum gauge and scan tool set on the fuel tank differential pressure sensor (TANK PRES SNER 73). The mechanical gauge reading is used to verify scan tool reading. A comparison of the mechanical gauge to scan tool determines the problem in the system.
2. Prior to doing the performance test, several simple inspections are needed to exclude some possibilities of the symptom.

The fuel gauge drive signal is input in ECM (terminal 74 - M/T) or PCM (terminal 60 - A/T).

1. Branch the drive signal from the fuel gauge circuit, and input it into ECM (M/T) or PCM (A/T).
2. The ECM (M/T) or PCM (A/T) detects the amount of fuel left in the fuel tank with this signal, and also controls the fuel level warning light.

5 volts are applied to the vehicle speed sensor output terminal (terminal 3) from the ECM (terminal 86). The vehicle speed sensor generates a pulse signal when the output terminal is opened and grounded.

1. The vehicle speed sensor converts the vehicle speed into pulse signals and inputs them to the ECM.
2. The vehicle speed sensor outputs a pulse signal while the vehicle is driven.
3. The ECM checks whether the pulse signal is output.

1. The idle air control motor power is supplied from the MFI relay (terminal 4).
2. The ECM (terminals 4, 5, 17, 18 - M/T) or PCM (terminals 14, 15, 28, 29 - A/T) drives the stepper motor by sequentially turning "ON" the power transistors in the ECM (M/T) or PCM (A/T) and providing ground to the idle air control motor (terminals 1, 3, 4, 6).

1. The amount of air taken in during idling is regulated by the opening and closing of the servo valve located in the air passage that bypasses the throttle body.
2. If there is a malfunction of the IAC system, the actual engine speed will not be identical to the target engine speed.
3. The ECM (M/T) or PCM (A/T) checks the difference between the actual engine speed and the target engine speed.

1. The idle air control motor power is supplied from the MFI relay (terminal 4).
2. The ECM (terminals 4, 5, 17, 18 - M/T) or PCM (terminals 14, 15, 28, 29 - A/T) drives the stepper motor by sequentially turning "ON" the power transistors in the ECM (M/T) or PCM (A/T) and providing ground to the idle air control motor (terminals 1, 3, 4, 6).

1. The amount of air taken in during idling is regulated by the opening and closing of the servo valve located in the air passage that bypasses the throttle body.
2. If there is a malfunction of the IAC system, the actual engine speed will not be identical to the target engine speed.
3. The ECM (M/T) or PCM (A/T) checks the difference between the actual engine speed and the target engine speed.

A battery positive voltage is applied to the power steering pressure switch output terminal (terminal 1) from the ECM (terminal 37 - M/T) or PCM (terminal 52 - A/T) via the resistor in the ECM (M/T) or PCM (A/T).

1. The power steering pressure switch converts the existence of a power steering load into a high/low voltage, and inputs it into the ECM (M/T) or PCM (A/T).
2. When the steering wheel is turned, hydraulic pressure rises. The power steering pressure switch closes, and the applied battery positive voltage will be grounded. With this, the power steering pressure switch output voltage will fluctuate between 12 volts and 0 volts.
3. While driving with the steering wheel held straight, the power steering pressure switch turns "OFF".
4. The ECM (M/T) or PCM (A/T) checks whether the power steering pressure switch turns "OFF" or "ON" during driving.

1. 5 volts are applied on the manifold differential pressure sensor power terminal (terminal 3) from the ECM (terminal 81 - M/T) or PCM (terminal 46 - A/T). The ground terminal (terminal 2) is grounded with the ECM (terminal 92 - M/T) or PCM (terminal 57 - A/T).
2. A voltage proportional to the pressure in the intake manifold plenum is sent from the manifold differential pressure sensor output terminal (terminal 1) to the ECM (terminal 73 - M/T) or PCM (terminal 91 - A/T).

1. The manifold differential pressure sensor outputs a voltage which corresponds to the negative pressure in the intake manifold.
2. The ECM (M/T) or PCM (A/T) checks whether the voltage output by manifold differential pressure sensor is within a specified range.

The ECM (terminal 41 - M/T) or PCM (terminal 54 - A/T) apply a battery positive voltage into the generator FR terminal 4 via resistance inside the unit.

1. When the generator field coils are controlled, the generator FR terminal inputs signal to the ECM (M/T) or PCM (A/T).
2. The ECM (M/T) or PCM (A/T) detects the generator output with the input signal, and controls the idle air control motor according to generator output.

Note. When the system detects an open circuit in the battery backup line, it makes 1 failure judgement of other diagnostic trouble codes (DTCs).

The ECM (M/T) or PCM (A/T) checks for open circuit in battery backup line.

1. ECM (M/T) or PCM (A/T) monitors the communication condition with the immobilizer-ECU and the message from the immobilizer-ECU, and when the abnormality is found, ECM (M/T) or PCM (A/T) disables the ignition.

See also:
• FUEL PUMP RELAY & MFI RELAY
• EXHAUST GAS RECIRCULATION (EGR)