Description
The service engine soon/malfunction indicator lamp power is supplied from the ignition switch. The PCM controls the ground of the service engine soon/malfunction indicator lamp by turning the power transistor in the PCM on and off. The PCM causes the service engine soon/malfunction indicator lamp to illuminate for 5 seconds immediately after the ignition switch is turned to ON position. (Scheme 143)
Scheme 143
The service engine soon/malfunction indicator lamp power is supplied from the ignition switch. The PCM controls the ground of the service engine soon/malfunction indicator lamp by turning the power transistor in the PCM on and off. In such cases, the cause is probably that the PCM is detecting a problem in a sensor or actuator, or that one of the malfunctions listed has occurred. (Scheme 143)
A battery positive voltage is applied on the data link connector power terminal (terminal No. 16). The ground terminals (terminals No. 4 and 5) are grounded to the vehicle body. The cause is probably a defect in power supply system (including ground) for the on-board diagnostic test mode line. (Scheme 144)
Scheme 144
A diagnostic output is made from the PCM terminal No. 85 to the diagnostic output terminal (terminal No. 7) of the data link connector. (Scheme 144)and (Scheme 145).
Scheme 145
CONNECTOR IDENTIFICATION
Note. The following connector illustrations are shown as viewed from component side of connector.
| Connector | Illustration |
|---|---|
| Auto Cruise Control ECU | (Scheme 146) |
| Camshaft Position (CMP) Sensor | (Scheme 147) |
| Crankshaft Position (CKP) Sensor | (Scheme 148) |
| Data Link Connector | (Scheme 149) |
| EGR Solenoid | (Scheme 150) |
| Engine Coolant Temperature (ECT) Sensor | (Scheme 151) |
| Evap Purge Solenoid | (Scheme 152) |
| Evap Vent Solenoid | See scheme 39 |
| Fuel Injector | (Scheme 153) |
| Fuel Pump Relay | (Scheme 154) |
| Fuel Tank Differential Pressure (FTDP) Sensor | (Scheme 155) |
| Fuel Temperature Sensor | (Scheme 156) |
| Generator Field | (Scheme 157) |
| Heated Oxygen Sensor (HO2S) | (Scheme 158) |
| Idle Air Control (IAC) Motor | (Scheme 159) |
| Immobilizer ECU | (Scheme 160) |
| Instrument Cluster | (Scheme 161) |
| Intermediate Connector B-13 | (Scheme 162) |
| Intermediate Connector B-26 | (Scheme 163) |
| Intermediate Connector C-17 | (Scheme 164) |
| Intermediate Connector C-71 | (Scheme 165) |
| Intermediate Connector D-16 | (Scheme 166) |
| Knock Sensor (KS) | (Scheme 167) |
| Manifold Differential Pressure (MDP) Sensor | See scheme 55 |
| MFI Relay | (Scheme 154) |
| Powertrain Control Module (PCM) | (Scheme 168) |
| Throttle Position (TP) Sensor | (Scheme 169) |
| Vehicle Speed Sensor (VSS) | See scheme 58 |
| Volume Airflow (VAF) Sensor | (Scheme 170) |
TERMINAL IDENTIFICATION DIRECTORY
Scheme 146
Scheme 147
Scheme 148
Scheme 149
Scheme 150
Scheme 151
Scheme 152
Scheme 153
Scheme 154
Scheme 155
Scheme 156
Scheme 157
Scheme 158
Scheme 159
Scheme 160
Scheme 161
Scheme 162
Scheme 163
Scheme 164
Scheme 165
Scheme 166
Scheme 167
Scheme 168
Scheme 169
Scheme 170
While the engine is running, the volume airflow sensor outputs a pulse signal which corresponds to the volume of air flow. The PCM checks whether the frequency of this signal output by the volume airflow sensor while the engine is running is at or above the set value. When the throttle position sensor output voltage is low, the PCM causes the power transistor to be ON to send an airflow sensor reset signal to the airflow sensor. In response to the reset signal, the airflow sensor resets the filter circuit and improves the ability of the airflow sensor to measure the amount of air in a small air intake region.
Operation
The volume airflow sensor power is supplied from the MFI relay (terminal No. 4), and the ground is provided on PCM terminal No. 16. 5-volt power is applied to the volume airflow sensor output terminal (terminal No. 3) from PCM terminal No. 65. The volume airflow sensor generates a pulse signal when the output terminal and ground are opened/closed (Open/Short). see scheme 1, see scheme 27, see scheme 28, see scheme 31 and (Scheme 171).
Scheme 171
While the engine is running, the volume airflow sensor outputs a pulse signal which corresponds to the volume of air flow. The PCM checks whether the frequency of this signal output by the volume airflow sensor while the engine is running is at or above the set value.
The volume airflow sensor power is supplied from the MFI relay (terminal No. 4), and the ground is provided on the PCM terminal No. 16. 5-volt power is applied to the volume airflow sensor output terminal (terminal No. 3) from the PCM terminal No. 65. The volume airflow sensor generates a pulse signal when the output terminal and ground are opened/closed (open/short). see scheme 1, see scheme 27, see scheme 28, see scheme 31, (Scheme 154) and (Scheme 171).
A 5-volt voltage is supplied to the barometric pressure sensor power terminal (terminal No. 1) from the PCM terminal No. 46. The ground terminal (terminal No. 5) is grounded with PCM terminal No. 16. A voltage that is proportional to the atmospheric pressure is sent to the PCM terminal No. 55 from the barometric pressure sensor output terminal (terminal No. 2). The barometric pressure sensor outputs a voltage which corresponds to the barometric pressure. The PCM checks whether this voltage is within a specified range. see scheme 28, see scheme 31 and (Scheme 172).
Scheme 172
A 5-volt voltage is supplied to the barometric pressure sensor power terminal (terminal No. 1) from the PCM terminal No. 46. The ground terminal (terminal No. 5) is grounded with PCM terminal No. 16. A voltage that is proportional to the atmospheric pressure is sent to the PCM terminal No. 55 from the barometric pressure sensor output terminal (terminal No. 2). The barometric pressure sensor outputs a voltage which corresponds to the barometric pressure. The PCM checks whether this voltage is within a specified range. see scheme 28, see scheme 31 and (Scheme 172).
The barometric pressure sensor outputs a voltage which corresponds to the barometric pressure. The PCM checks whether this voltage is within a specified range.
A 5-volt voltage is supplied to the barometric pressure sensor power terminal (terminal No. 1) from the PCM terminal No. 46. The ground terminal (terminal No. 5) is grounded with PCM terminal No. 16. A voltage that is proportional to the atmospheric pressure is sent to the PCM terminal No. 55 from the barometric pressure sensor output terminal (terminal No. 2). see scheme 28, see scheme 31 and (Scheme 172).
The intake air temperature sensor converts the intake air temperature to a voltage. The PCM checks whether this voltage is within a specified range.
Approximately 5 volts are applied to the Intake Air Temperature (IAT) sensor output terminal (terminal No. 6) from the PCM terminal No. 64 via the resistor in the PCM. The ground terminal (terminal No. 5) is grounded with PCM terminal No. 16. The IAT sensor is a negative temperature coefficient type of resistor. When the intake air temperature rises, the resistance decreases. The IAT sensor output voltage increases when the resistance increases and decreases when the resistance decreases. see scheme 28, see scheme 31 and (Scheme 173).
Scheme 173
The Intake Air Temperature (IAT) converts the intake air temperature to a voltage. The PCM checks whether this voltage is within a specified range.
Approximately 5 volts are applied to the Intake Air Temperature (IAT) sensor output terminal (terminal No. 6) from the PCM terminal No. 64 via the resistor in the PCM. The ground terminal (terminal No. 5) is grounded with PCM terminal No. 16. The IAT sensor is a negative temperature coefficient type of resistor. When the intake air temperature rises, the resistance decreases. The IAT sensor output voltage increases when the resistance increases and decreases when the resistance decreases. see scheme 28, see scheme 31 and (Scheme 173).
The Intake Air Temperature (IAT) sensor converts the intake air temperature to a voltage. The PCM checks whether this voltage is within a specified range.
Approximately 5 volts are applied to the Intake Air Temperature (IAT) sensor output terminal (terminal No. 6) from the PCM terminal No. 64 via the resistor in the PCM. The ground terminal (terminal No. 5) is grounded with PCM terminal No. 16. The IAT sensor is a negative temperature coefficient type of resistor. When the intake air temperature rises, the resistance decreases. The IAT sensor output voltage increases when the resistance increases and decreases when the resistance decreases. see scheme 28, see scheme 31 and (Scheme 173).
The engine coolant temperature sensor converts the engine coolant temperature to a voltage and outputs it. The PCM checks whether this voltage is within a specified range.
5-volts is applied to the engine coolant temperature sensor output terminal (terminal No. 1) from the PCM terminal No. 44 via the resistor in the PCM. The ground terminal (terminal No. 2) is grounded with PCM terminal No. 57. The engine coolant temperature sensor is a negative temperature coefficient type of resistance. It has the characteristic that when the engine coolant temperature rises the resistor decreases. The engine coolant temperature sensor output voltage increases when the resistance increases and decreases when the resistance decreases. see scheme 9, see scheme 28, (Scheme 151) and (Scheme 174).
Scheme 174
The engine coolant temperature sensor converts the engine coolant temperature to a voltage and output it. The PCM checks whether this voltage is within a specified range.
5-volt voltage is applied to the engine coolant temperature sensor output terminal (terminal No. 1) from the PCM terminal No. 44 via the resistor in the PCM. The ground terminal (terminal No. 2) is grounded with PCM terminal No. 57. 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. The engine coolant temperature sensor output voltage increases when the resistance increases and decreases when the resistance decreases. see scheme 9, see scheme 28, (Scheme 151) and (Scheme 174).
The engine coolant temperature sensor converts the engine coolant temperature to a voltage and outputs it. The PCM checks whether this voltage is within a specified range.
A 5-volt voltage is applied to the engine coolant temperature sensor output terminal (terminal No. 1) from the PCM terminal No. 44 via the resistor in the PCM. The ground terminal (terminal No. 2) is grounded with PCM terminal No. 57. 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. The engine coolant temperature sensor output voltage increases when the resistance increases and decreases when the resistance decreases. see scheme 9, see scheme 28, (Scheme 151) and (Scheme 174).
The Throttle Position (TP) sensor outputs voltage which corresponds to the throttle valve opening angle. The PCM checks whether the voltage is within a specified range.
A 5-volt power supply is applied on the Throttle Position (TP) sensor power terminal (terminal No. 4) from the PCM terminal No. 46. The ground terminal (terminal No. 1) is grounded with PCM terminal No. 57. When the throttle valve shaft is turned from the idle position to the fully opened position, the resistance between the TP sensor output terminal (terminal No. 3) and ground terminal will increase according to the rotation. see scheme 28, see scheme 30, (Scheme 169) and (Scheme 175).
Scheme 175
The Throttle Position (TP) sensor outputs voltage which corresponds to the throttle valve opening angle. The PCM 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.
A 5-volt power supply is applied on the Throttle Position (TP) sensor power terminal (terminal No. 4) from the PCM terminal No. 46. The ground terminal (terminal No. 1) is grounded with PCM terminal No. 57. When the throttle valve shaft is turned from the idle position to the fully opened position, the resistance between the TP sensor output terminal (terminal No. 3) and ground terminal will increase according to the rotation. see scheme 28, see scheme 30, (Scheme 169) and (Scheme 175).
The Throttle Position (TP) sensor outputs voltage which corresponds to the throttle valve opening angle. The PCM 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.
A 5-volt power supply is applied on the Throttle Position (TP) sensor power terminal (terminal No. 4) from the PCM terminal No. 46. The ground terminal (terminal No. 1) is grounded with PCM terminal No. 57. When the throttle valve shaft is turned from the idle position to the fully opened position, the resistance between the TP sensor output terminal (terminal No. 3) and ground terminal will increase according to the rotation. see scheme 28, see scheme 30, (Scheme 169) and (Scheme 175).
The engine coolant temperature sensor converts the engine coolant temperature to a voltage and outputs it. The PCM checks whether this voltage is within a specified range.
5-volt voltage is applied to the engine coolant temperature sensor output terminal (terminal No. 1) from the PCM terminal No. 44 via the resistor in the PCM. The ground terminal (terminal No. 2) is grounded with PCM terminal No. 57. 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. The engine coolant temperature sensor output voltage increases when the resistance increases and decreases when the resistance decreases. see scheme 9, see scheme 28 and (Scheme 174).
The PCM checks the time for the engine coolant temperature to reach the judgment temperature.
A voltage corresponding to oxygen concentration in exhaust gas is sent to PCM terminal No. 72 from right bank heated oxygen sensor (front) terminal No. 4. Terminal No. 2 of right bank heated oxygen sensor (front) is grounded by PCM terminal No. 57.
The right bank heated oxygen sensor (front) detects the concentration of oxygen in the exhaust gas; it converts those data to voltage, and inputs the resulting signals to PCM. When the right bank heated oxygen sensor (front) begins to deteriorate, the heated oxygen sensor signal response becomes poor. The PCM forcibly varies the air/fuel mixture to make it leaner and richer, and checks the response speed of the right bank heated oxygen sensor (front). In addition, the PCM also checks for an open circuit in the right bank heated oxygen sensor (front) output line. see scheme 15, see scheme 28, (Scheme 158) and (Scheme 176).
Scheme 176
The right bank heated oxygen sensor (front) detects the concentration of oxygen in the exhaust gas; it converts those data to voltage, and inputs the resulting signals to the PCM. When the right bank heated oxygen sensor (front) begins to deteriorate, the heated oxygen sensor signal response becomes poor. The PCM forcibly varies the air/fuel mixture to make it leaner and richer, and checks the response speed of the right bank heated oxygen sensor (front). In addition, the PCM also checks for an open circuit in the right bank heated oxygen sensor (front) output line.
A voltage corresponding to the oxygen concentration in the exhaust gas is sent to the PCM terminal No. 72 from the output terminal (terminal No. 4) of the right bank heated oxygen sensor (front). Terminal No. 2 of the right bank heated oxygen sensor (front) is grounded with PCM terminal No. 57. see scheme 15, see scheme 28, (Scheme 158) and (Scheme 176).
The PCM effects air/fuel ratio feedback control in accordance with the signals from the right bank heated oxygen sensor (front). If the right bank heated oxygen sensor (front) has deteriorated, corrections will be made by the heated oxygen sensor (rear). DTC P0134 becomes stored in memory if a failure is detected in the air/fuel ratio feedback control system.
Refer to DTC P0132: HEATED OXYGEN SENSOR (BANK 1, SENSOR 1) CIRCUIT HIGH VOLTAGE, DTC P0201, DTC P0203 & DTC P0205. see scheme 12, see scheme 15, see scheme 28, (Scheme 158) and (Scheme 176).
The PCM checks whether the heater current is within a specified range when the heater is energized.
Power is supplied from the MFI relay (terminal No. 4) to the right bank heated oxygen sensor (front) heater. The PCM terminal No. 4 controls continuity to the right bank heated oxygen sensor (front) heater by turning the power transistor on and off in the PCM. see scheme 15, see scheme 27, see scheme 28, (Scheme 158) and see scheme 68.
Scheme 177
The output signal of the heated oxygen sensor (front) is compensated by the output signal of the right bank heated oxygen sensor (rear). The PCM checks for an open circuit in the right bank heated oxygen sensor (rear) output line.
A voltage corresponding to the oxygen concentration in the exhaust gas is sent to the PCM terminal No. 74 from the output terminal (terminal No. 4) of the right bank heated oxygen sensor (rear). Terminal No. 2 of the right bank heated oxygen sensor (rear) is grounded with PCM terminal No. 57.
The output signal of the heated oxygen sensor (front) is compensated by the output signal of the right bank heated oxygen sensor (rear). The PCM checks for an open circuit in the right bank heated oxygen sensor (rear) output line.
A voltage corresponding to the oxygen concentration in the exhaust gas is sent to the PCM terminal No. 74 from the output terminal (terminal No. 4) of the right bank heated oxygen sensor (rear). Terminal No. 2 of the right bank heated oxygen sensor (rear) is grounded with PCM terminal No. 57. see scheme 16, see scheme 28, (Scheme 158) and see scheme 69.
The output signal of the heated oxygen sensor (front) is compensated by the output signal of the right bank heated oxygen sensor (rear). The PCM checks for an open circuit in the right bank heated oxygen sensor (rear) output line.
A voltage corresponding to the oxygen concentration in the exhaust gas is sent to the PCM terminal No. 73 from the output terminal (terminal No. 3) of the right bank right bank heated oxygen sensor (rear). Terminal No. 4 of the right bank heated oxygen sensor (rear) is grounded with PCM terminal No. 57. see scheme 16, see scheme 28, (Scheme 158) and see scheme 69.
Power is supplied from the MFI relay (terminal No. 1) to the right bank heated oxygen sensor (rear) heater. The PCM terminal No. 27 controls continuity to the right bank heated oxygen sensor (rear) heater by turning the power transistor in the PCM on and off. The PCM checks whether the heater current is within a specified range when the heater is energized. see scheme 16, see scheme 27, see scheme 28, (Scheme 158) and (Scheme 179).
Scheme 178
The heated oxygen sensor (left front) detects the concentration of oxygen in the exhaust gas; it converts those data to voltage, and inputs the resulting signals to PCM. When the left bank heated oxygen sensor (front) begins to deteriorate, the heated oxygen sensor signal response becomes poor. The PCM forcibly varies the air/fuel mixture to make it leaner and richer, and checks the response speed of the left bank heated oxygen sensor (front). In addition, the PCM also checks for an open circuit in the left bank heated oxygen sensor (front) output line.
see scheme 17, see scheme 28, (Scheme 158) and (Scheme 180).
Scheme 179
A voltage corresponding to oxygen concentration in exhaust gas is sent to PCM terminal No. 71 from left bank heated oxygen sensor (front) terminal No. 4. Terminal No. 2 of left bank heated oxygen sensor (front) is grounded by PCM terminal No. 57.
The left bank heated oxygen sensor (front) detects the concentration of oxygen in the exhaust gas; it converts those data to voltage, and inputs the resulting signals to the PCM. When the left bank heated oxygen sensor (front) begins to deteriorate, the heated oxygen sensor signal response becomes poor. The PCM forcibly varies the air/fuel mixture to make it leaner and richer, and checks the response speed of the left bank heated oxygen sensor (front). In addition, the PCM also checks for an open circuit in the left bank heated oxygen sensor (front) output line.
A voltage corresponding to the oxygen concentration in the exhaust gas is sent to the PCM terminal No. 72 from the output terminal (terminal No. 4) of the left bank heated oxygen sensor (front). Terminal No. 2 of the left bank heated oxygen sensor (front) is grounded with PCM terminal No. 57. see scheme 17, see scheme 28, (Scheme 158) and (Scheme 180).
The PCM effects air/fuel ratio feedback control in accordance with the signals from the left bank heated oxygen sensor (front). If the left bank heated oxygen sensor (front) has deteriorated, corrections will be made by the heated oxygen sensor (rear). DTC P0134 becomes stored in memory if a failure is detected in the above air/fuel ratio feedback control system.
Refer to DTC P0152: HEATED OXYGEN SENSOR (BANK 2, SENSOR 1) CIRCUIT HIGH VOLTAGE and DTC P0201, DTC P0203 & DTC P0205. see scheme 17, see scheme 28, (Scheme 158) and (Scheme 180).
The PCM checks whether the heater current is within a specified range when the heater is energized.
Power is supplied from the MFI relay (terminal No. 4) to the left bank heated oxygen sensor (front) heater. The PCM terminal No. 4 controls continuity to the left bank heated oxygen sensor (front) heater by turning the power transistor on and off in the PCM. see scheme 17, see scheme 27, see scheme 28, (Scheme 158) and see scheme 73.
Scheme 180
The output signal of the left bank heated oxygen sensor (front) is compensated by the output signal of the left bank heated oxygen sensor (rear). The PCM checks for an open circuit in the left bank heated oxygen sensor (rear) output line.
A voltage corresponding to the oxygen concentration in the exhaust gas is sent to the PCM terminal No. 73 from the output terminal (terminal No. 4) of the left bank heated oxygen sensor (rear). Terminal No. 2 of the left bank heated oxygen sensor (rear) is grounded with PCM terminal No. 57.
The output signal of the heated oxygen sensor (front) is compensated by the output signal of the left bank heated oxygen sensor (rear). The PCM checks for an open circuit in the left bank heated oxygen sensor (rear) output line.
A voltage corresponding to the oxygen concentration in the exhaust gas is sent to the PCM terminal No. 73 from the output terminal (terminal No. 4) of the left bank heated oxygen sensor (rear). Terminal No. 2 of the left bank heated oxygen sensor (rear) is grounded with PCM terminal No. 57. see scheme 18, see scheme 28, (Scheme 158) and (Scheme 181).
The output signal of the left bank heated oxygen sensor (front) is compensated by the output signal of the left bank heated oxygen sensor (rear). The PCM checks for an open circuit in the left bank heated oxygen sensor (rear) output line.
A voltage corresponding to the oxygen concentration in the exhaust gas is sent to the PCM terminal No. 73 from the output terminal (terminal No. 4) of the left bank left bank heated oxygen sensor (rear). Terminal No. 4 of the left bank heated oxygen sensor (rear) is grounded with PCM terminal No. 57. see scheme 18, see scheme 28, (Scheme 158) and (Scheme 181).
Power is supplied from the MFI relay (terminal No. 4) to the left bank heated oxygen sensor (rear) heater. The PCM terminal No. 26 controls continuity to the left bank heated oxygen sensor (rear) heater by turning the power transistor in the PCM on and off. The PCM checks whether the heater current is within a specified range when the heater is energized. see scheme 18, see scheme 27, see scheme 28, (Scheme 158) and (Scheme 182).
Scheme 181
If a malfunction occurs in the fuel system, the fuel trim value becomes too large. The PCM checks whether the fuel trim value is within a specified range.
Refer to DTC P0201, DTC P0203 & DTC P0205. see scheme 12and see scheme 28.
If a malfunction occurs in the fuel system, the fuel trim value becomes too small. The PCM checks whether the fuel trim value is within a specified range.
Refer to DTC P0201, DTC P0203 & DTC P0205.
If a malfunction occurs in the fuel system, the fuel trim value becomes too large. The PCM checks whether the fuel trim value is within a specified range.
Refer to DTC P0202, DTC P0204 & DTC P0206.
If a malfunction occurs in the fuel system, the fuel trim value becomes too small. The PCM checks whether the fuel trim value is within a specified range.
Refer to DTC P0202, DTC P0204 & DTC P0206.
The fuel temperature sensor converts the fuel temperature to a voltage. The PCM detects the fuel temperature in the fuel tank with this output voltage.
5-volt voltage is applied to the fuel temperature sensor output terminal (terminal No. 3) from the PCM terminal No. 51 via the resistor in the PCM. The fuel temperature sensor output voltage increases when the resistance increases and decreases when the resistance decreases. The ground terminal (terminal No. 1) is grounded to the vehicle body. see scheme 13, see scheme 23, see scheme 28 and (Scheme 183).
Scheme 182
The fuel temperature sensor converts the fuel temperature to a voltage. The PCM detects the fuel temperature in the fuel tank with this output voltage.
5 volts is applied to the fuel temperature sensor output terminal (terminal No. 3) from the PCM terminal No. 51 via the resistor in the PCM. The fuel temperature sensor output voltage increases when the resistance increases and decreases when the resistance decreases. The ground terminal (terminal No. 1) is grounded to the vehicle body. see scheme 13, see scheme 23, see scheme 28 and (Scheme 183).
The fuel temperature sensor converts the fuel temperature to a voltage. The PCM detects the fuel temperature in the fuel tank with the output voltage.
PCM applies 5-volts via internal resistor to the fuel temperature sensor output terminal (terminal No. 3) from the PCM terminal No. 51. The fuel temperature sensor output voltage increases when the resistance increases and decreases when the resistance decreases. The fuel temperature sensor ground terminal (terminal No. 1) is grounded to the vehicle body. see scheme 13, see scheme 23, see scheme 28 and (Scheme 183).
The amount of fuel injected by the injector is controlled by the amount of continuity time the coil is grounded by the PCM. A surge voltage is generated when the injectors are driven and the current flowing to the injector coil is shut off. The PCM checks this surge voltage.
The injector power is supplied from the MFI relay terminal No. 4 to each injector (terminal No. 1). The PCM controls the injector by turning the power transistor in the PCM on and off. see scheme 12, see scheme 27, see scheme 28, (Scheme 153) and (Scheme 184).
Scheme 183
The amount of fuel injected by the injector is controlled by the amount of continuity time the coil is grounded by the PCM. A surge voltage is generated when the injectors are driven and the current flowing to the injector coil is shut off. The PCM checks this surge voltage.
The injector power is supplied from the MFI relay to each injector (terminal No. 1). The PCM controls the injector by turning the power transistor in the PCM on and off. see scheme 12, see scheme 27, see scheme 28, (Scheme 153) and (Scheme 186).
Scheme 184
If a misfire occurs while the engine is running, the engine speed changes for an instant. The PCM checks for such changes in engine speed.
Refer to DTC P0201, DTC P0203 & DTC P0205 and DTC P0202, DTC P0204 & DTC P0206. see scheme 12and see scheme 28.
If a misfire occurs while the engine is running, the engine speed changes for an instant. The PCM checks for such changes in engine speed.
Refer to DTC P0201, DTC P0203 & DTC P0205 and DTC P0202, DTC P0204 & DTC P0206. see scheme 12and see scheme 28.
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. The PCM checks whether the voltage output changes.
The knock sensor sends a signal voltage to the PCM terminal No. 90. see scheme 25, see scheme 28, (Scheme 167) and (Scheme 187).
Scheme 185
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 PCM When the engine is running, the crankshaft position sensor outputs a pulse signal. The PCM checks whether pulse signal is input while the engine is cranking.
The crankshaft position sensor power is supplied from the MFI relay (terminal No. 4), terminal No. 1 of the crankshaft position sensor is grounded by PCM terminal No. 16. 5-volts is applied on the crankshaft position sensor output terminal (terminal No. 2) from the PCM terminal No. 45. The crankshaft position sensor generates a pulse signal when the output terminal is opened and grounded. see scheme 7, see scheme 27, see scheme 28, (Scheme 154) and (Scheme 188).
Scheme 186
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 PCM. When the engine is running, the camshaft position sensor outputs a pulse signal. The PCM checks whether pulse signal is input while the engine is cranking.
The camshaft position sensor power is supplied from the MFI relay (terminal No. 4). Terminal No. 7 of the camshaft position sensor is grounded with PCM terminal No. 16. A 5-volt voltage is applied to the camshaft position sensor output terminal (terminal No. 5) from the PCM terminal No. 56. The camshaft position sensor generates a pulse signal when the output terminal is opened and grounded. see scheme 5, see scheme 27, see scheme 28, (Scheme 154) and (Scheme 190).
Scheme 187
When the EGR solenoid switches from OFF to ON while the engine is running, EGR gas flows. The PCM checks how the EGR gas flow signal changes.
The PCM checks current flows in the EGR solenoid drive circuit when the EGR solenoid is on and off.
The EGR solenoid power (terminal No. 1) is supplied from the MFI relay (terminal No. 4). The PCM controls the EGR solenoid ground (terminal No. 2) by turning the power transistor on and off at the PCM terminal No. 6. see scheme 8, see scheme 27, see scheme 28, (Scheme 150) and (Scheme 192).
Scheme 188
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. The PCM compares the output of the front and rear heated oxygen sensor signals.
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. The PCM compares the output of the front and rear heated oxygen sensor signals.
PCM detects stuck open evaporative emission purge solenoid valve or stuck closed evaporative emission ventilation solenoid valve by pressure change in fuel tank. Stuck open evaporative emission purge solenoid valve is judged through monitoring leak of evaporative emission control system. Stuck closed evaporative emission ventilation solenoid valve is judged after 20 seconds of end of monitoring leak of evaporative emission control system, or of usual operation of evaporative emission purge solenoid from ON to OFF.
see scheme 10and see scheme 11.
To judge if there is leak in the fuel system, PCM measure the change of the pressure inside the fuel tank. The PCM turns on the evaporative emission ventilation solenoid to shut off the evaporative emission canister outlet port. Then the evaporative emission purge solenoid is driven to set the fuel system into a negative pressure. 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). The PCM determines if there is leak in the fuel system by measuring the change of vacuum inside the fuel tank. The test is stopped when fuel vapor pressure is judged as too high.
Scheme 189
Scheme 190
Scheme 191
Scheme 192
Scheme 193
Scheme 194
Scheme 195
Scheme 196
Scheme 197
Scheme 198
Scheme 199
Scheme 200
Scheme 201
Overview Of Troubleshooting
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. Prior to doing the performance test, several simple inspections are needed to exclude some possibilities of the symptom.
To judge if there is open circuit in the evaporative emission purge solenoid drive circuit, PCM measures the surge voltage of the evaporative emission ventilation solenoid coil. The PCM drives the evaporative emission purge solenoid for 30 milliseconds. After the solenoid is turned off, the PCM will check if the solenoid coil produces a surge voltage of 2 volts or more.
Power to the evaporative emission purge solenoid power is supplied from the MFI relay (terminal No. 4). The PCM controls ground of evaporative emission purge solenoid by turning the power transistor in the PCM on and off. see scheme 10, see scheme 27, see scheme 28, (Scheme 152), (Scheme 193) and (Scheme 206).
Scheme 202
To judge if there is an open circuit in the evaporative emission ventilation solenoid drive circuit, PCM measures the surge voltage of the evaporative emission ventilation solenoid coil. The PCM drives the evaporative emission ventilation solenoid for 30 milliseconds. After the solenoid is turned off, the PCM will check if the solenoid coil produces a surge voltage of 2 volts or more.
The evaporative emission ventilation solenoid power is supplied from the MFI relay (terminal No. 4). The PCM controls the evaporative emission ventilation solenoid ground by turning the power transistor in the PCM on and off. see scheme 11, see scheme 22, see scheme 23, see scheme 24, see scheme 27, see scheme 28, (Scheme 193) and see scheme 102.
Scheme 203
To judge if the fuel tank differential pressure sensor is defective, the PCM monitors the fuel tank differential pressure sensor output voltage. Based on the test conditions and judgment criteria, the PCM judges if the fuel tank differential pressure sensor output voltage is normal.
A 5-volt voltage is supplied to the power terminal of the fuel tank differential pressure sensor (terminal No. 3) from the PCM terminal No. 46. The fuel tank differential pressure sensor ground terminal (terminal No. 2) is grounded with the PCM terminal No. 57. A voltage proportional to the pressure in the fuel tank is sent from the output terminal of the fuel tank differential pressure sensor (terminal No. 1) to the PCM terminal No. 92. see scheme 14, see scheme 28, (Scheme 155), (Scheme 166), (Scheme 193) and (Scheme 207).
Scheme 204
DTC P0451 can be set by faulty fuel differential pressure sensor, related circuit, or PCM.
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.
To judge if the fuel tank differential pressure sensor is defective, the PCM monitors the fuel tank differential pressure sensor output voltage. Based on the test conditions and judgment criteria, the PCM judges if the fuel tank differential pressure sensor output voltage is normal.
5-volts is supplied to the power terminal of the fuel tank differential pressure sensor (terminal No. 3) from the PCM terminal No. 46. The ground terminal (terminal No. 2) is grounded with the PCM terminal No. 57. A voltage proportional to the pressure in the fuel tank is sent from the output terminal of the fuel tank differential pressure sensor (terminal No. 1) to the PCM terminal No. 92. see scheme 14, see scheme 28, (Scheme 155), (Scheme 166), (Scheme 193) and (Scheme 207).
The DTC P0452 can be set if either faulty fuel differential pressure sensor, related circuit, or PCM.
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.
To judge if the fuel tank differential pressure sensor is defective, the PCM monitors the fuel tank differential pressure sensor output voltage. Based on the test conditions and judgment criteria, the PCM judges if the fuel tank differential pressure sensor output voltage is normal.
A 5-volt voltage is supplied to the power terminal of the fuel tank differential pressure sensor (terminal No. 3) from the PCM terminal No. 46. The ground terminal (terminal No. 2) is grounded with the PCM terminal No. 57. A voltage proportional to the pressure in the fuel tank is sent from the output terminal of the fuel tank differential pressure sensor (terminal No. 1) to the PCM terminal No. 92. see scheme 14, see scheme 28, (Scheme 155), (Scheme 166), (Scheme 193) and (Scheme 207).
The DTC P0453 can be set if a faulty fuel differential pressure sensor, related circuit, or PCM exists. 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.
To judge if there is leak or clog in the fuel system, the PCM measures the change in pressure inside the fuel tank. The PCM turns on the evaporative emission ventilation solenoid to shut off the evaporative emission canister outlet port. Then the evaporative emission purge solenoid is driven to set the fuel system into a negative pressure. 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). The PCM determines if there is leak or clog in the fuel system by measuring the change of vacuum inside the fuel tank. The test is stopped when fuel vapor pressure is judged as too high.
see scheme 11, see scheme 22, see scheme 23, see scheme 24, see scheme 27, see scheme 28, (Scheme 193) and see scheme 102.
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. Prior to doing the performance test, several simple inspections are needed to exclude some possibilities of the symptom.
To judge if there is leak in the fuel system, PCM measures the change of the pressure inside the fuel tank. The PCM turns on the evaporative emission ventilation solenoid valve to shot off the evaporative emission canister outlet port. Then the evaporative emission purge solenoid valve is driven to set the fuel system into a negative pressure. 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). The PCM determines if there is leak in the fuel system by measuring the change of vacuum inside the fuel tank. The test is stopped when fuel vapor pressure is judged as too high.
see scheme 11, see scheme 22, see scheme 23, see scheme 24, see scheme 27, see scheme 28, (Scheme 193) and see scheme 102.
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. Prior to doing the performance test, several simple inspections are needed to exclude some possibilities of the symptom.
The drive signal from the fuel gauge circuit is split to the gauge and to input in PCM. The PCM detects the amount of fuel left in the fuel tank with this signal, and also controls the fuel level warning light.
The fuel gauge drive signal is input in PCM terminal No. 60. see scheme 13, see scheme 23, see scheme 28 and (Scheme 208).
Scheme 205
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. If there is a malfunction of the IAC system, the actual engine speed will not be identical to the target engine speed. The PCM checks the difference between the actual engine speed and the target engine speed.
The idle air control motor power is supplied from the MFI relay (terminal No. 4). The PCM (terminals No. 14, 15, 28 and 29) drives the stepper motor by sequentially turning on the power transistors in the PCM and providing ground to the idle air control motor (terminals No. 1, 3, 4 and 6). see scheme 19, see scheme 27, see scheme 28, (Scheme 159) and (Scheme 209).
Scheme 206
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. If there is a malfunction of the IAC system, the actual engine speed will not be identical to the target engine speed. The PCM checks the difference between the actual engine speed and the target engine speed.
The idle air control motor power is supplied from the MFI relay (terminal No. 4). The PCM (terminals No. 14, 15, 28 and 29) drives the stepper motor by sequentially turning on the power transistors in the PCM and providing ground to the idle air control motor (terminals No. 1, 3, 4 and 6). see scheme 19, see scheme 27, see scheme 28, (Scheme 159) and (Scheme 209).
The power steering pressure switch converts the existence of a power steering load into a high/low voltage, and inputs it into the PCM. When the steering wheel is turned, hydraulic pressure rises, the power steering pressure switch closes, and the applied battery positive voltage will be grounded. When steering wheel is turned, the power steering pressure switch output voltage will change from 12 volts and 0 volt. While driving with the steering wheel held straight, the power steering pressure switch turns off. The PCM checks whether the power steering pressure switch turns off or on during driving.
Battery positive voltage is applied to the power steering pressure switch output terminal (terminal No. 1) from the PCM terminal No. 52 via the resistor in the PCM. see scheme 28, see scheme 29 and (Scheme 211).
Scheme 207
The manifold differential pressure sensor outputs a voltage which corresponds to the negative pressure in the intake manifold. The PCM checks whether the voltage output by manifold differential pressure sensor is within a specified range.
A 5-volt voltage is applied on the manifold differential pressure sensor power terminal (terminal No. 3) from the PCM terminal No. 46. The ground terminal (terminal No. 2) is grounded with the PCM terminal No. 57. A voltage proportional to the pressure in the intake manifold plenum is sent from the manifold differential pressure sensor output terminal (terminal No. 1) to the PCM terminal No. 91. see scheme 26, see scheme 28 and see scheme 108.
Scheme 208
When the generator field coils are controlled, the generator FR terminal inputs signal to the PCM. The PCM detects the generator output with the input signal, and controls the idle air control motor according to the generator output.
The PCM terminal No. 54 applies a battery positive voltage into the generator FR terminal No. 4 via resistance inside the unit. see scheme 21, see scheme 28, (Scheme 157), (Scheme 162), see scheme 109 and see scheme 110.
Scheme 209
Scheme 210
The PCM is checks the open circuit of battery backup line. When the system detects an open circuit in the battery backup line, it makes one failure judgment of other Diagnostic Trouble Codes (DTC).
see scheme 28and see scheme 111.
Scheme 211
PCM monitors the communication condition with the immobilizer-ECU and the message from the immobilizer-ECU. When the abnormality is found, PCM does not allow the engine to start.
See also:
• POWER CIRCUITS
• GROUND CIRCUITS
• SYSTEM & COMPONENT TESTING