Engine Control System (1GR-FE) (Diagnostic Codes (P043E - P1605)): Overview Toyota Tacoma II рестайлинг

DESCRIPTION

The circuit description can be found in the EVAP (Evaporative Emission System. Refer to INSPECTION PROCEDURE .

MONITOR DESCRIPTION

5 hours * after the ignition switch is turned off, the electric leak detection pump creates negative pressure (vacuum) in the EVAP) system. The ECM monitors for leaks and actuator malfunctions based on the EVAP pressure.

HINT

* : If the engine coolant temperature is not below 35°C (95°F) 5 hours after the ignition switch is turned off, the monitor check starts 2 hours later. If it is still not below 35°C (95°F) 7 hours after the ignition switch is turned off, the monitor check starts 2.5 hours later.

* If only a small amount of fuel is in the fuel tank, it takes longer for the EVAP pressure to stabilize.

Scheme 129

TEXT IN ILLUSTRATION

The leak detection pump creates negative pressure through the reference orifice (in operation B and E). When the system is normal, the EVAP pressure is between 97 to 100 kPa(abs) [724 to 752 mmHg(abs)]* and saturated within a minute. If not, the ECM interprets this as a malfunction. The ECM illuminates the MIL and stores a DTC if this malfunction is detected in consecutive drive cycles.

*: Typical value.

Scheme 130

The circuit description can be found in the EVAP (Evaporative Emission) System. Refer to DESCRIPTION .

The 2 monitors, Key-Off and Purge Flow, are used to detect malfunctions relating to DTC P0441. The Key-Off monitor is initiated by the ECM internal timer, known as the soak timer, 5 hours * after the ignition switch is turned off. The purge flow monitor runs while the engine is running.

Scheme 131

Scheme 132

1. KEY-OFF MONITOR 5 hours * after the ignition switch is turned off, the electric leak detection pump creates negative pressure (vacuum) in the EVAP system. The ECM monitors for leaks and actuator malfunctions based on the EVAP pressure. HINT: * : If the engine coolant temperature is not below 35°C (95°F) 5 hours after the ignition switch is turned off, the monitor check starts 2 hours later. If it is still not below 35°C (95°F) 7 hours after the ignition switch is turned off, the monitor check starts 2.5 hours later. Sequence Operation Description Duration - ECM activation Activated by soak timer, 5 hours (7 or 9.5 hours) after ignition switch turned off. - A Atmospheric pressure measurement Vent valve turned OFF (vent) and EVAP system pressure measured by ECM in order to register atmospheric pressure. If pressure in EVAP system not between 70 kPa(abs) and 110 kPa(abs) [525 mmHg(abs) and 825 mmHg(abs)], ECM cancels EVAP system monitor. 60 seconds B First reference pressure measurement In order to determine reference pressure, leak detection pump creates negative pressure (vacuum) through reference orifice and then ECM checks if leak detection pump and vent valve operate normally. 360 seconds C EVAP system pressure measurement Vent valve turned ON (closed) to shut EVAP system. Negative pressure (vacuum) created in EVAP system, and EVAP system pressure then measured. Write down measured value as they will be used in leak check. If EVAP pressure does not stabilize within 15 minutes, ECM cancels EVAP system monitor. 15 minutes * D Purge VSV monitor Purge VSV opened and then EVAP system pressure measured by ECM. Large increase indicates normal. 10 seconds E Second reference pressure measurement After second reference pressure measurement, leak check performed by comparing first and second reference pressure. If stabilized system pressure higher than second reference pressure, ECM determines that EVAP system leaking. 60 seconds F Final check Atmospheric pressure measured and then monitoring result recorded by ECM. - * If only a small amount of fuel is in the fuel tank, it takes longer for the EVAP pressure to stabilize. TEXT IN ILLUSTRATION *1 Purge VSV: OFF (closed) *2 Purge VSV: ON (open) *3 Vent Valve: OFF (vent) *4 Vent Valve: ON (closed) *5 Leak Detection Pump: OFF *6 Leak Detection Pump: ON *7 Reference Orifice (0.02 inch) *8 Canister Pressure Sensor *9 Canister *10 Fuel Tank *11 Canister Pump Module *12 Canister Filter *a Operation A: Atmospheric Pressure Measurement *b Operation B, E: Reference Pressure Measurement *c Operation C: EVAP System Pressure Measurement *d Operation D: Purge VSV Monitor *e Atmospheric Pressure *f Negative Pressure Purge VSV stuck open In operation C, the leak detection pump creates negative pressure (vacuum) in the EVAP (Evaporative Emission) system. The EVAP system pressure is then measured by the ECM using the canister pressure sensor. If the stabilized system pressure is higher than [second reference pressure x 0.2], the ECM interprets this as the purge VSV being stuck open. The ECM illuminates the MIL and stores the DTC (2 trip detection logic). Purge VSV stuck closed In operation D, the canister pressure sensor measures the EVAP (Evaporative Emission) system pressure. The pressure measurement for the purge VSV monitor begins when the purge VSV is turned on (open) after the EVAP leak check. When the measured pressure indicates an increase of 0.3 kPa(gauge) [2.25 mmHg(gauge)] or more, the purge VSV is functioning normally. If the pressure does not increase, the ECM interprets this as the purge VSV being stuck closed. The ECM illuminates the MIL and stores the DTC (2 trip detection logic).
2. PURGE FLOW MONITOR

The purge flow monitor consists of 2 monitors. The 1st monitor is conducted every time and the 2nd monitor is activated if necessary.

Scheme 133

1. The 1st monitor While the engine is running and the purge VSV is ON (open), the ECM monitors the purge flow by measuring the EVAP pressure change. If negative pressure is not created, the ECM begins the 2nd monitor.
2. The 2nd monitor The vent valve is turned ON (closed) and the EVAP pressure is then measured. If the variation in the pressure is less than 0.15 kPa(gauge) [1.13 mmHg(gauge)], the ECM interprets this as the purge VSV being stuck closed, illuminates the MIL and stores DTC P0441 (2 trip detection logic).

Atmospheric pressure check

In order to ensure reliable malfunction detection, the variation between the atmospheric pressures, before and after conduction of the purge flow monitor, is measured by the ECM.

HINT

This DTC P0443 is applicable to Mexico models only.

To reduce hydrocarbon emissions, evaporated fuel from the fuel tank is routed through a canister to the intake manifold for combustion in the cylinders.

The ECM changes the duty signals to the Purge VSV (Vacuum Switching Valve for Purge Control) so that the intake amount of hydrocarbon emissions is appropriate for the driving conditions (engine load, engine speed, vehicle speed, etc.) after the engine is warmed up.

Scheme 134

The circuit description can be found in the EVAP (Evaporative Emission) System. Refer to DESCRIPTION .

Scheme 135

1. DTC P0451: Canister pressure sensor noise or fixed/flat If the canister pressure sensor voltage output fluctuates rapidly for 10 seconds, the ECM stops the EVAP system monitor. The ECM interprets this as noise from the canister pressure sensor, and stops the EVAP system monitor. The ECM then illuminates the MIL and stores the DTC. Alternatively, if the sensor voltage output does not change for 10 seconds, the ECM interprets this as the sensor being stuck, and stops the monitor. The ECM then illuminates the MIL and stores the DTC (Both the malfunctions are detected by 2 trip detection logic).
2. DTC P0452: Canister pressure sensor voltage low If the canister pressure sensor voltage output (pressure) is below 0.45 V: 42.11009 kPa(abs) [315.8516 mmHg(abs)], the ECM interprets this as an open or short circuit malfunction in the canister pressure sensor or its circuit, and stops the EVAP system monitor. The ECM then illuminates the MIL and stores the DTC (1 trip detection logic).
3. DTC P0453: Canister pressure sensor voltage high If the canister pressure sensor voltage output (pressure) is 4.9 V: 123.76147 kPa(abs) [928.2874 mmHg(abs)] or more, the ECM interprets this as an open or short circuit malfunction in the canister pressure sensor or its circuit, and stops the EVAP system monitor. The ECM then illuminates the MIL and stores the DTC (1 trip detection logic).

The circuit description can be found in the EVAP (Evaporative Emission) System. Refer to INSPECTION PROCEDURE .

5 hours * after the ignition switch is turned off, the leak detection pump creates negative pressure (vacuum) in the EVAP system. The ECM monitors for leaks and actuator malfunctions based on the EVAP pressure.

HINT

* : If the engine coolant temperature is not below 35°C (95°F) 5 hours after the ignition switch is turned off, the monitor check starts 2 hours later. If it is still not below 35°C (95°F) 7 hours after the ignition switch is turned off, the monitor check starts 2.5 hours later.

* If only a small amount of fuel is in the fuel tank, it takes longer for the EVAP pressure to stabilize.

TEXT IN ILLUSTRATION

Scheme 136

1. P0455: EVAP gross leak In operation C, the leak detection pump creates negative pressure (vacuum) in the EVAP system and the EVAP system pressure is measured. If the stabilized system pressure is higher than [second reference pressure x 0.2] (near atmospheric pressure), the ECM determines that the EVAP system has a large leakage, illuminates the MIL and stores the DTC (2 trip detection logic).
2. P0456: EVAP very small leak In operation C, the leak detection pump creates negative pressure (vacuum) in the EVAP system and the EVAP system pressure is measured. If the stabilized system pressure is higher than second reference pressure, the ECM determines that the EVAP system has a small leak, illuminates the MIL and stores the DTC (2 trip detection logic).

Vehicles, which are equipped with ABS (Anti-lock Brake System), detect the vehicle speed using the skid control ECU (brake actuator assembly) and wheel speed sensor. The wheel speed sensor monitors the wheel rotation speed and sends a signal to the skid control ECU (brake actuator assembly). The skid control ECU (brake actuator assembly) converts the wheel speed signal into a 4-pulse signal and transmits it to the ECM via the combination meter assembly. The ECM determines the vehicle speed based on the frequency of the pulse signal.

HINT

1. Various systems use the vehicle speed signal distributed from the combination meter. Check all the components possibly related to speed signal.
2. A voltage of 12 V or 5 V is output from each ECU and then input to the combination meter assembly. The signal is changed to a pulse signal at the transistor in the combination meter assembly. Each ECU controls the respective system based on the pulse signal.
3. If a short occurs in any of the ECUs or in the wire harness connected to an ECU, all systems using the speed signal will not operate normally.

Scheme 137

Automatic Transmission Models

The ECM assumes that the vehicle is being driven when the indicated vehicle speed is 9 km/h (5.59 mph) or more. If these is no speed signal from the combination meter assembly despite these conditions being met, the ECM interprets this as a malfunction in the speed signal circuit. The ECM then illuminates the MIL and stores the DTC.

Manual Transmission Models

The ECM assumes that the vehicle is being driven when the idle fuel-cut operation is being executed. If these is no speed signal from the combination meter assembly, despite these condition being met, the ECM interprets this as a malfunction in the speed signal circuit. The ECM then illuminates the MIL and stores the DTC.

The stop light switch assembly is a duplex system that transmits two signals: STP and ST1-. These two signals are used by the ECM to monitor whether or not the brake system is working properly. If the signals, which indicate the brake pedal is being depressed and released, are detected simultaneously, the ECM interprets this as a malfunction in the stop light switch assembly and stores the DTC.

HINT

The normal switch conditions are as shown in the table below.

1. [OFF] denotes ground potential.
2. [ON] denotes battery potential (+B).
3. On the Techstream, both the Data List items Stop Light Switch and ST1 are ON when the brake pedal is depressed because the ST1 indication characteristic is opposite to the Stop Light Switch indication.

Scheme 138

The idling speed is controlled by the ETCS (electronic throttle control system). The ETCS is comprised of: 1) the one valve type throttle body; 2) the throttle actuator, which operates the throttle valve; 3) the throttle position sensor, which detects the opening angle of the throttle valve; 4) the accelerator pedal position sensor, which detects the accelerator pedal position; and 5) the ECM, which controls the ETCS. Based on the target idling speed, the ECM controls the throttle actuator to provide the proper throttle valve opening angle.

The ECM monitors the idling speed and idling air flow volume to conduct idle speed control. The ECM determines that the idle speed control system is malfunctioning if the following conditions are met

1. The difference between the target engine idling speed and actual engine idling speed exceeds the threshold and the IAC flow rate learned value is stuck at the upper or lower limit for 5 seconds or more.
2. After driving at a vehicle speed of 10 km/h (6.25 mph) or more, the difference between the target and actual engine idling speed exceeds the threshold 5 times or more during a driving cycle, and then the system determines that the IAC flow rate learned value is stuck at the upper or lower limit, or that the IAC flow rate learned value has been changed by an amount that exceeds the threshold.

Scheme 139

This monitor will run when the engine is started at an engine coolant temperature of -10°C (14°F) or higher, and less than 50°C (122°F). The DTC will stored after the engine idles for 13 seconds (2 trip detection logic).

The DTC is designed to monitor the idle air control at cold start. When the engine is started at an engine coolant temperature of less than 50°C (122°F), the ECM measures the accumulated mass air flow at engine idling. If it does not reach the specified level within 10 seconds, the ECM interprets this as a malfunction. The MIL is illuminated and a DTC is stored when the malfunction is detected in consecutive driving cycles (2 trip detection logic).

The ETCS (electronic throttle control system) controls the idle speed. The electronic throttle control system operates the throttle actuator to open and close the throttle valve, and adjusts the intake air amount to achieve the target idle speed.

Note. When the cable is disconnected from the negative (-) battery terminal during inspections or repairs, the idle speed control learned values are cleared. This DTC cannot be stored with the idle speed control learned values cleared.

HINT

The ISC learning is performed when the engine is warmed up and has been idling for 5 minutes.

Scheme 140

This monitor will run when the engine is started at an engine coolant temperature of -10°C (14°F) or more, and less than 50°C (122°F). The DTC will stored after the engine idles for 13 seconds (2 trip detection logic).

The DTC is designed to monitor the ignition timing at cold start. When the engine is started at an engine coolant temperature of less than 50°C (122°F), the ECM checks the ignition timing at engine idling. If the ignition timing advances beyond the specified level within 10 seconds, the ECM interprets this as a malfunction. The MIL is illuminated and a DTC is stored when the malfunction is detected in consecutive driving cycles (2 trip detection logic).

Note. When the cable is disconnected from the negative (-) battery terminal during inspections or repairs, the idle speed control learned values are cleared. This DTC cannot be stored with the idle speed control learned values cleared.

HINT

The idle speed control learning is performed when the engine is warmed up and has been idling for 5 minutes.

Scheme 141

The battery supplies electricity to the ECM even when the ignition switch is off. This power allows the ECM to store data such as DTC history, freeze frame data and fuel trim values. If the battery voltage falls below a minimum level, these memories are cleared and the ECM determines that there is a malfunction in the power supply circuit. When the engine is next started, the ECM illuminates the MIL and stores the DTC.

HINT

If DTC P0560 is stored, the ECM does not store other DTCs.

The ECM continuously monitors its internal memory status. This self-check ensures that the ECM is functioning properly. It is diagnosed by internal "mirroring" of the main CPU and sub CPU to detect the Random Access Memory (RAM) errors. If outputs from these CPUs are different and deviate from the standards, the ECM will illuminate the MIL and stores a DTC immediately.

The ECM continuously monitors its main and sub CPUs. This self-check ensures that the ECM is functioning properly. If outputs from the CPUs are different and deviate from the standard, the ECM will illuminate the MIL and stores DTC(s) immediately.

The ECM continuously monitors its internal processors (CPUs) and heated oxygen sensor transistors. This self-check ensures that the ECM is functioning properly.

The main CPU and sub CPU of the ECM perform data communication between each other. The main CPU monitors the communications and WDC pulses from the sub CPU. When the signal malfunctions below are detected, a DTC is stored.

This DTC is output when a communication error occurs in the ECM.

The ECM monitors the input signals of the accelerator pedal position sensor No. 1. When the input signals and control signals are deviated, a DTC is stored.

The ECM monitors the input signals of the throttle position sensor No. 1 and stop light switch assembly. As the ECM monitors the input signals of the throttle position sensor No. 1 and the STP signals of the stop light switch assembly, if the input signals and control signals are deviated, a DTC is stored.

While the engine is being cranked, the positive battery voltage is applied to terminal STA of the ECM. If the ECM detects the Starter Control (STA) signal while the vehicle is being driven, it determines that there is a malfunction in the STA circuit. The ECM then illuminates the MIL and stores the DTC.

This monitor runs when the vehicle is driven at 20 km/h (12.43 mph) for over 20 seconds.

1. *1: for Automatic Transmission *2: for Manual Transmission

The ECM monitors its internal operation and it stores this DTC when it detects an internal malfunction.

The ECM monitors its internal operation. If the internal operation is malfunctioning, the ECM illuminates the MIL and stores a DTC.

DTC P0630 is stored when the Vehicle Identification Number (VIN) is not stored in the ECM or the input VIN is not accurate. Input the VIN with the Techstream.

The ECM monitors the output voltage to the throttle actuator. This self-check ensures that the ECM is functioning properly. The output voltage usually is 0 V when the ignition switch is turned off. If the output voltage is higher than 7 V when the ignition switch is turned off, the ECM will illuminate the MIL and stores a DTC when the ignition switch is turned to ON.

The stop light switch assembly is part of a duplex system that transmits 2 signals: STP and ST1-. These 2 signals are used by the ECM to monitor whether or not the brake system is working properly. This DTC indicates that the stop light switch assembly remains on. When the stop light switch remains on during GO and STOP driving, the ECM interprets this as a fault in the stop light switch. Then the MIL illuminates and the ECM stores the DTC.

This DTC indicates that the stop light switch assembly remains ON. When the stop light switch assembly remains ON during "STOP and GO" driving, the ECM interprets this as a fault in the stop light switch assembly and the MIL comes on and the ECM stores the DTC. The vehicle must stop (less than 3 km/h [1.86 mph]) and go (30 km/h [18.64 mph] or more) 5 times during 2 driving cycles, in order to detect a malfunction.

HINT

*: Name of Data List item

The pressure detected by the canister pressure sensor and the pressures detected by the pressure sensors of both air switching valve (bank 1 or bank 2) are checked 50 minutes after the ignition switch is turned off. If the pressure detected by the canister pressure sensor and the pressure detected by the pressure sensor of either air switching valve (bank 1 or bank 2) differ by a certain amount, the MIL is illuminated and a DTC is stored (2 trip detection logic).

HINT

Correct judgment may not be possible when the elevation is 4000 m (13120 ft.) or more.

The ECM operates the AIR PUMP HTR relay which causes the air pump heater to operate.

These DTCs are designed to detect a malfunction in the AIR PUMP HTR relay circuit. When the system is normal, the battery voltage is applied to terminal HAI1 of the ECM while the AIR PUMP HTR relay is turned off, and the battery voltage is not applied to terminal HAI1 of the ECM while the AIR PUMP HTR relay is turned on. The ECM illuminates the MIL and stores a DTC when either one of the following conditions is detected.

1. The battery voltage is not applied to terminal HAI1 while the AIR PUMP HTR relay is off.
2. The battery voltage is applied to terminal HAI1 while the AIR PUMP HTR relay is on.

This DTC P1500 is applicable to Mexico models only.

This vehicle is equipped with a voltage inverter, which supplies power to various electrical appliances. When the main switch of the voltage inverter is turned ON, the inverter relay turns ON, and the inverter then converts the 12 V Direct Current (DC) of the battery into an 115 V Alternating Current (AC). The voltage inverter can output a maximum of 400 W from an outlet.

When the AC 115 V is output, a load is applied to the engine. The ECM controls the engine idling speed according to the vehicle speed and engine load. A speed signal is input to the inverter and an idle-up signal is transmitted to the ECM.

Scheme 142

While the engine is idling, the ECM performs idle-up according to the power supply of the inverter to stabilize the engine idling speed.

When the vehicle is stationary and the inverter input exceeds 8.3 A, the inverter sends an idle-up signal from the OUT terminal of the inverter to the ELS2 terminal of the ECM.

If the idle-up signal is input into the ECM for 10 seconds while the vehicle is running, the ECM interprets this as a malfunction in the inverter circuit and stores the DTC.

Scheme 143

P1603

After starting the engine, this DTC is stored when the engine stops without the ignition switch being operated.

Using the Techstream, the conditions present when the DTC was stored can be confirmed by referring to the freeze frame data. Freeze frame data records engine conditions when a malfunction occurs. This information can be useful when troubleshooting.

It is necessary to check if the vehicle has run out of fuel before performing troubleshooting, as this DTC is also stored when the engine stalls due to running out of fuel.

*1: for Automatic Transmission

P1605

This DTC is stored if the engine speed drops below the set speed without the ignition switch being operated.

Using the Techstream, the conditions present when the DTC was stored can be confirmed by referring to the freeze frame data. Freeze frame data records engine conditions when a malfunction occurs. This information can be useful when troubleshooting.

It is necessary to check if the vehicle ran out of fuel before performing troubleshooting, as this DTC is also stored when idling is unstable due to running out of fuel.

*1: for Automatic Transmission

Scheme 144

Scheme 145

1. Reference waveforms showing a normal cold engine start
2. Reference waveforms showing a normal warm engine start
3. Reference values when there is an air leak in the intake system during rough idling FREEZE FRAME DATA P1605 ROUGH IDLING Parameter -3 -2 -1 0 1 Unit Engine Speed 694 693 412 384 114 RPM Calculate Load 31.7 31.7 34.5 35.6 92.5 % Vehicle Load 13.3 13.7 27.4 29.4 22.3 % MAF 3.75 3.79 4.53 4.46 1.01 gm/sec Atmosphere Pressure -1 -1 -1 -1 -1 psi (gauge) Coolant Temp 181 181 181 181 181 F Intake Air 111 111 111 111 111 F Battery Voltage 13.085 13.085 12.753 12.753 12.675 V Throttle Sensor Volt % 14.9 14.9 16.0 16.0 17.2 % Throttl Sensor #2 Volt % 47.0 47.0 48.2 48.2 49.8 % Throttle Sensor Position 0.0 0.0 0.0 0.0 0.0 % Throttle Motor DUTY 14.9 14.9 16.0 16.0 17.2 % Injector (Port) 2382 2379 2649 2649 2975 μs Injection Volum (Cylinder 1) 0.112 0.112 0.112 0.112 0.112 ml Fuel Pump/Speed Status ON ON ON ON ON EVAP (Purge) VSV 0.0 0.0 0.0 0.0 0.0 % EVAP Purge Flow 0.0 0.0 0.0 0.0 0.0 % Purge Density Learn Value 0.000 0.000 0.000 0.000 0.000 EVAP System Vent Valve OFF OFF OFF OFF OFF EVAP Purge VSV OFF OFF OFF OFF OFF Purge Cut VSV Duty 0.0 0.0 0.0 0.0 0.0 % Target Air-Fuel Ratio 0.998 0.998 0.998 0.998 0.832 AF Lambda B1S1 0.994 0.988 0.997 0.998 1.049 AF Lambda B2S1 0.996 0.988 0.997 0.998 1.049 AFS Voltage B1S1 3.219 3.185 3.244 3.254 3.517 V AFS Voltage B2S1 3.224 3.180 3.239 3.239 3.512 V O2S B1S2 0.000 0.000 0.000 0.000 0.000 V O2S B2S2 0.000 0.000 0.000 0.000 0.000 V Short FT #1 9.375 9.375 7.031 7.031 0.000 % Long FT #1 0.000 0.000 0.000 0.000 0.000 % Total FT #1 0.000 0.000 0.000 0.000 0.000 Sort FT #2 9.375 8.593 7.031 7.031 0.000 % Long FT #2 0.781 0.781 0.781 0.781 0.781 % Total FT #2 0.000 0.000 0.000 0.000 0.000 Fuel System Status #1 CL CL CL CL CL Fuel System Status #2 CL CL CL CL CL IGN Advance 14.5 15.5 18.0 18.0 18.0 deg Knock Feedback Value -3.0 -3.0 -3.0 -3.0 -3.0 deg(CA) Knock Correct Learn Value 23.1 23.1 23.1 23.1 23.1 deg(CA) Starter Signal OFF OFF OFF OFF OFF

See also:
• INSPECTION PROCEDURE
• INSPECTION
• REMOVAL
• ON-VEHICLE INSPECTION - Step 1
• REMOVAL
• REMOVAL
• ON-VEHICLE INSPECTION
• ON-VEHICLE INSPECTION
• ON-VEHICLE INSPECTION