Engine Control System (Diagnostic Codes (P1604-PA200) & Circuit Tests): Overview Toyota Yaris II рестайлинг

DESCRIPTION

This DTC is stored when the engine does not start even though the STA signal is input or when the engine takes a long time to start, and when the engine speed is low or the engine stalls just after the engine starts.

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 there is engine starting trouble due to running out of fuel.

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1. Reference waveforms showing a normal cold engine start
2. Reference waveforms showing a normal warm engine start
3. Reference waveforms showing an engine stop after normal idling
4. Reference values when there is an air leak in the air induction system during starting difficulty FREEZE FRAME DATA P1604 STARTABILITY MALFUNCTION Parameter -3 -2 -1 0 1 Unit Engine Speed 1497 794 334 249 249 rpm Calculate Load 34.5 28.2 32.1 87.8 87.4 % Vehicle Load 8.6 21.9 15.6 7.4 5.8 % MAF 1.70 2.31 0.70 0.25 0.20 gm/sec Atmosphere Pressure -1 -1 -1 -1 -1 psi(gauge) Coolant Temp 167 167 167 167 167 F Intake Air 93 93 93 93 93 F Ambient Temperature 66 66 66 66 66 F Battery Voltage 13.2 13.0 12.3 12.3 12.3 V Throttle Sensor Volt % 16.0 17.6 17.2 15.6 15.6 % Throttle Sensor #2 Volt % 48.2 50.1 49.4 47.8 47.8 % Throttle Sensor Position 0.0 0.0 0.0 0.0 0.0 % Throttle Motor DUTY 16.0 17.6 17.6 15.6 15.6 % Injector (Port) 3204 2562 2562 2562 2562 μs Injection Volume (Cylinder 1) 0.152 0.152 0.152 0.152 0.152 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 Purge VSV OFF OFF OFF OFF OFF Target Air-Fuel Ratio 0.830 0.841 0.871 0.799 0.799 AF Lambda B1 S1 1.014 1.016 1.021 1.022 1.027 AFS Voltage B1 S1 3.37 3.38 3.40 3.41 3.42 V O2S B1 S2 0.82 0.31 0.07 0.05 0.03 V Short FT #1 0.000 0.000 0.000 0.000 0.000 % Long FT #1 0.000 -4.069 -4.737 -4.737 -4.737 % Total FT #1 -0.043 -0.043 -0.043 -0.043 -0.043 Fuel System Status #1 OL OL OL OL OL IGN Advance -4.0 2.0 4.0 0.0 0.0 deg Knock Feedback Value -3.0 -3.0 -3.0 -3.0 -3.0 CA Knock Correct Learn Value 14.0 14.0 14.0 14.0 14.0 CA VVT Control Status #1 OFF OFF OFF OFF OFF Starter Signal Close Close Close Close Close

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 store a DTC immediately.

The throttle actuator is operated by the ECM and opens and closes the throttle valve using gears.

The opening angle of the throttle valve is detected by the Throttle Position (TP) sensor, which is mounted on the throttle body. The TP sensor provides feedback to the ECM. This feedback allows the ECM to appropriately control the throttle actuator and monitor the throttle opening angle as the ECM responds to driver inputs.

HINT

This ETCS (Electronic Throttle Control System) does not use a throttle cable.

MONITOR DESCRIPTION

The ECM monitors the electrical current through the electronic actuator, and detects malfunctions and open circuits in the throttle actuator based on this value. If the current is outside the standard range, the ECM determines that there is a malfunction in the throttle actuator. In addition, if the throttle valve does not function properly (for example, stuck on), the ECM determines that there is a malfunction. The ECM then illuminates the MIL and sets a DTC.

Example

When the electrical current is less than 0.5 A and the throttle actuator duty ratio exceeds 80 %, the ECM interprets this as the current being outside the standard range, and illuminates the MIL and sets a DTC.

If the malfunction is not repaired successfully, a DTC is set when the engine is quickly revved to a high rpm several times after the engine has idled for 5 seconds after engine start.

The idling speed is controlled by the Electronic Throttle Control System (ETCS).

The ETCS is comprised of a throttle actuator, which operates the throttle valve, and a throttle position sensor, which detects the opening amount of the throttle valve.

The ECM controls the throttle actuator to adjust the throttle valve opening amount so that the idling speed is maintained at the target idling speed.

If there are deposits in the throttle valve, the necessary ISC flow rate for idling is maintained using the ISC learning value and feedback as a decrease in the ISC flow rate may cause engine stall or unstable idling. The ECM stores this DTC if the ISC learning value approaches its limit.

The throttle actuator is operated by the ECM, and opens and closes the throttle valve using gears. The opening angle of the throttle valve is detected by the Throttle Position (TP) sensor, which is mounted on the throttle body. The TP sensor provides feedback to the ECM in order that it can control the throttle actuator, and therefore the throttle valve, appropriately in response to driver inputs.

HINT

This ETCS (Electronic Throttle Control System) does not use a throttle cable.

The ECM determines that there is a malfunction in the ETCS when the throttle valve remains at a fixed angle despite a high drive current from the ECM. The ECM illuminates the MIL and sets a DTC.

If the malfunction is not repaired successfully, a DTC is set when the accelerator pedal is fully depressed and released quickly (to fully open and close the throttle valve) after the engine is next started.

The ETCS (Electronic Throttle Control System) has a dedicated power supply circuit. The voltage (+BM) is monitored and when it is low (less than 4 V), the ECM determines that there is a malfunction in the ETCS and cuts off the current to the throttle actuator.

When the voltage becomes unstable, the ETCS itself becomes unstable. For this reason, when the voltage is low, the current to the throttle actuator is cut. If repairs are made and the system returns to normal, turn the ignition switch off. The ECM then allows the current to flow to the throttle actuator so that it can be restarted.

HINT

The ETCS does not use a throttle cable.

Scheme 141

The ECM monitors the battery supply voltage applied to the throttle actuator.

When the power supply voltage (+BM) drops below 4 V for 0.8 seconds or more, the ECM interprets this as an open in the power supply circuit (+BM). The ECM illuminates the MIL and sets the DTC.

If the malfunction is not repaired successfully, the DTC is set 5 seconds after the engine is next started.

The Electronic Throttle Control System (ETCS) is composed of the throttle actuator, Throttle Position (TP) sensor, Accelerator Pedal Position (APP) sensor, and ECM. The ECM operates the throttle actuator to regulate the throttle valve in response to driver inputs. The TP sensor detects the opening angle of the throttle valve, and provides the ECM with feedback so that the throttle valve can be appropriately controlled by the ECM.

The ECM determines the actual opening angle of the throttle valve from the TP sensor signal. The actual opening angle is compared to the target opening angle commanded by the ECM. If the difference between these two values is outside the standard range, the ECM interprets this as a malfunction in the ETCS. The ECM then illuminates the MIL and sets the DTC.

If the malfunction is not repaired successfully, the DTC is set when the accelerator pedal is quickly released (to close the throttle valve) after the engine speed reaches 5,000 rpm by the accelerator pedal being fully depressed (fully open the throttle valve).

HINT

1. These DTCs relate to the Accelerator Pedal Position (APP) sensor.
2. This ETCS (Electronic Throttle Control System) does not use a throttle cable.

The APP sensor is mounted on the accelerator pedal bracket and has 2 sensor circuits: VPA (main) and VPA2 (sub). This sensor is a non-contact type, and uses Hall-effect elements, in order to yield accurate signals, even in extreme driving conditions, such as at high speeds as well as very low speeds. The voltage, which is applied to terminals VPA and VPA2 of the ECM, varies between 0 V and 5 V in proportion to the operating angle of the accelerator pedal (throttle valve). A signal from VPA indicates the actual accelerator pedal opening angle (throttle valve opening angle) and is used for engine control. A signal from VPA2 conveys the status of the VPA circuit and is used to check the APP sensor itself.

The ECM monitors the actual accelerator pedal opening angle (throttle valve opening angle) through the signals from VPA and VPA2, and controls the throttle actuator according to these signals.

Scheme 142

HINT

When any of these DTCs are set, check the APP sensor voltage by entering the following menus on a Techstream: Powertrain / Engine and ECT / Data List / ETCS / Accel Sensor Out No. 1 and Accel Sensor Out No. 2.

When either output voltage of VPA or VPA2 deviates from the standard range, or the difference between the output voltages of the 2 sensor circuits is less than the threshold, the ECM determines that there is a malfunction in the APP sensor. The ECM then illuminates the MIL and sets a DTC.

Example

When the output voltage of VPA drops below 0.4 V for more than 0.5 seconds when the accelerator pedal is fully depressed, DTC P2122 is set.

If the malfunction is not repaired successfully, a DTC is set 2 seconds after the engine is next started.

HINT

1. This DTC relates to the Accelerator Pedal Position (APP) sensor.
2. Refer to DTC P2120. Refer to «DESCRIPTION»(ref-394517-S33760042222011040800000).

When the difference between the output voltages of VPA and VPA2 deviates from the standard, the ECM determines that the Accelerator Pedal Position (APP) sensor is malfunctioning. The ECM turns on the MIL and the DTC is set.

HINT

1. Although the DTC titles say oxygen sensor, these DTCs relate to the Air-Fuel Ratio (A/F) sensor.
2. Sensor 1 refers to the sensor mounted in front of the Three-Way Catalytic Converter (TWC) and located near the engine assembly.

The A/F sensor generates a voltage* that corresponds to the actual air-fuel ratio. This sensor voltage is used to provide the ECM with feedback so that it can control the air-fuel ratio. The ECM determines the deviation from the stoichiometric air-fuel ratio level, and regulates the fuel injection time. If the A/F sensor malfunctions, the ECM is unable to control the air-fuel ratio accurately.

The A/F sensor is of the planar type and is integrated with the heater, which heats the solid electrolyte (zirconia element). This heater is controlled by the ECM. When the intake air volume is low (the exhaust gas temperature is low), a current flows into the heater to heat the sensor, in order to facilitate accurate air-fuel ratio detection. In addition, the sensor and heater portions are narrower than the conventional type. The heat generated by the heater is conducted to the solid electrolyte through the alumina, and therefore the sensor activation is accelerated.

In order to obtain a high purification rate of the carbon monoxide (CO), hydrocarbon (HC) and nitrogen oxide (NOx) components in the exhaust gas, a TWC is used. For the most efficient use of the TWC, the air-fuel ratio must be precisely controlled so that it is always close to the stoichiometric level.

*: Value changes inside the ECM. Since the A/F sensor is the current output element, a current is converted into a voltage inside the ECM. Any measurements taken at the A/F sensor or ECM connectors will show a constant voltage.

Scheme 143

HINT

1. When either of these DTCs is set, check the A/F sensor output by entering the following menus on a Techstream: Powertrain / Engine and ECT / Data List / AFS Voltage B1S1.
2. Short-term fuel trim values can also be read using the Techstream.
3. The ECM regulates the voltages at the A1A+ and A1A- terminals of the ECM to a constant level. Therefore, the A/F sensor output voltage cannot be confirmed without using the Techstream.
4. If the A/F sensor is malfunctioning, the ECM sets the DTC P2195 or P2196.

Sensor voltage detection monitor

Under the air-fuel ratio feedback control, if the A/F sensor output voltage indicates rich or lean for a certain period of time, the ECM determines that there is a malfunction in the A/F sensor. The ECM illuminates the MIL and sets a DTC.

Example

If the A/F sensor output voltage is less than 2.8 V (very rich condition) for 10 seconds, despite the rear HO2 sensor output voltage being less than 0.6 V, the ECM sets DTC P2196. Alternatively, if the A/F sensor output voltage is more than 3.8 V (very lean condition) for 10 seconds, despite the rear HO2 sensor output voltage being 0.15 V or more, DTC P2195 is set.

Sensor current detection monitor

A rich air-fuel mixture causes a low A/F sensor current, and a lean air-fuel mixture causes a high A/F sensor current. Therefore, the sensor output becomes low during acceleration, and it becomes high during deceleration with the throttle valve fully closed. The ECM monitors the A/F sensor current during fuel cut and detects any abnormal current values.

If the A/F sensor output is 3.6 mA or more for more than 3 seconds of cumulative time, the ECM interprets this as a malfunction in the A/F sensor and sets DTC P2195 (high-side stuck). If the A/F sensor output is less than 1.0 mA for more than 3 seconds of cumulative time, the ECM sets DTC P2196 (low-side stuck).

Scheme 144

HINT

1. Although the DTC titles say oxygen sensor, these DTCs relate to the Air-Fuel Ratio (A/F) sensor.
2. Sensor 1 refers to the sensor mounted in front of the Three-Way Catalytic Converter (TWC) and located near the engine assembly.

The A/F sensor, which is located between the exhaust manifold and catalyst, consists of alloyed metal elements and a heater.

Depending on the engine operating conditions, the heater heats the sensor elements to activate them. Battery voltage is applied to the heater, and the sensor ground is controlled by the ECM using a duty ratio.

The sensor elements convert the oxygen concentration in the exhaust gas into voltage values to output. Based on the voltage, the ECM determines the air-fuel ratio and regulates the fuel injection volume depending on the air-fuel ratio and engine operating conditions. The voltage changes between 0.6 V and 4.5 V while the engine is running. If the air-fuel ratio is lean, which means that the oxygen concentration in the exhaust gas is high, the voltage is high. If the air-fuel ratio is rich, which means the oxygen concentration in the exhaust gas is low, the voltage is low.

Scheme 145

These DTCs are output when there is an open or short in the Air-Fuel Ratio (A/F) sensor circuit, or if A/F sensor output drops. To detect these problems, the voltage of the A/F sensor is monitored when turning the ignition switch to the ON position, and the admittance (admittance is an electrical term that indicates the ease of flow of current) is checked while driving. If the voltage of the A/F sensor is between 0.6 V and 4.5 V, it is considered normal. If the voltage is out of the specified range, or the admittance is less than the standard value, the ECM will determine that there is a malfunction in the A/F sensor. If the same malfunction is detected in next driving cycle, the MIL will be illuminated and a DTC will be stored.

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

5 hours* after the ignition switch is turned to 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 to 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 to 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 146

P2420: Vent valve stuck open (vent)

In operation C, the vent valve turns ON (closes) and the EVAP system pressure is then measured by the ECM using the canister pressure sensor to conduct an EVAP leak check. If the pressure does not increase when the vent valve is open, the ECM interprets this as the vent valve being stuck open. The ECM illuminates the MIL and sets the DTC.

Scheme 147

The soak timer operates after the ignition switch is turned off. When a certain amount of time has elapsed after turning the ignition switch off the soak timer activates the ECM to perform malfunction checks which can only be performed after the engine is stopped. The soak timer is built into the ECM.

Scheme 148

1. While the engine is running, the ECM monitors the synchronization of the soak timer and the CPU clock. If these two are not synchronized, the ECM interprets this as a malfunction, illuminates the MIL and stores the DTC.
2. If the soak timer activates the ECM even though only a short amount of time has elapsed since the ignition switch was turned off, or if the soak timer does not activate the ECM even though a considerable amount of time has elapsed since the ignition switch was turned off, the ECM determines that the soak timer is malfunctioning, illuminates the MIL and stores a DTC the next time the ignition switch is turned ON.

HINT

Sensor 1 refers to the sensor mounted in front of the Three-Way Catalytic Converter (TWC) and located near the engine assembly.

Refer to DTC P2195. Refer to DESCRIPTION.

After the engine is warmed up, the ECM performs air-fuel ratio feedback control to maintain the air-fuel ratio at the stoichiometric level. In addition, active A/F control is performed for approximately 10 seconds after the preconditions are met in order to measure the A/F sensor response rate. During active A/F control, the ECM forcibly increases and decreases the injection volume a certain amount, based on the stoichiometric air-fuel ratio learned during normal air-fuel ratio control, and measures the A/F sensor response rate. The ECM receives a signal from the A/F sensor while performing active A/F control and uses it to calculate the A/F sensor response rate deterioration level.

If the A/F sensor response rate deterioration level is less than the threshold, the ECM interprets this as a malfunction and sets the DTC.

Scheme 149

HINT

Unit expressions

1. [kPa-a (mmHg-a)] denotes the absolute pressure.
2. [kPa-g (mmHg-g)] denotes the gauge pressure (relative pressure).
3. On a Techstream, convert the unit of measurement according to the inspection procedure.

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Scheme 151

Note. In this vehicle's EVAP system, turning ON the vent valve does not seal off the EVAP system. To check for leaks in the EVAP system, disconnect the air inlet vent hose and apply pressure from the atmospheric side of the canister.

While the engine is running, if a predetermined condition (closed-loop etc.) is met, the purge VSV is opened by the ECM and stored fuel vapors in the canister are purged into the intake manifold. The ECM changes the duty cycle ratio of the purge VSV to control purge flow volume.

The purge flow volume is also determined by the intake manifold pressure. Atmospheric pressure is allowed into the canister through the vent valve to ensure that the purge flow is maintained when the negative pressure (vacuum) is applied to the canister.

The following two monitors run to confirm the appropriate EVAP system operation.

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1. Key-off monitor This monitor checks for EVAP (Evaporative Emission) system leaks and canister pump module malfunctions. The monitor starts 5 hours * after the ignition switch is turned to OFF. At least 5 hours are required for the fuel to cool down to stabilize the EVAP pressure, thus making the EVAP system monitor more accurate. The leak detection pump creates negative pressure (vacuum) in the EVAP system and the pressure is measured. Finally, the ECM monitors for leaks from the EVAP system, and malfunctions in both the canister pump module and purge VSV, 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 to OFF, the monitor check starts 2.5 hours later.
2. Purge flow monitor The purge flow monitor consists of the two monitors. The 1st monitor is conducted every time and the 2nd monitor is activated if necessary. The 1st monitor While the engine is running and the purge VSV (Vacuum Switching Valve) 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. The 2nd monitor The vent valve is turned ON (closed) and the EVAP pressure is measured. If the variation in the pressure is less than 0.5 kPa-g (3.75 mmHg-g), the ECM interprets this as the purge VSV being stuck closed, and illuminates the MIL and sets 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. Components Operations Canister Contains activated charcoal to absorb EVAP (Evaporative Emissions) generated in fuel tank. Cut-off valve Located in fuel tank. Valve floats and closes when fuel tank 100 % full. Purge VSV (Vacuum Switching Valve) Opens or closes line between canister and intake manifold. ECM uses purge VSV to control EVAP purge flow. In order to discharge EVAP absorbed by canister to intake manifold, ECM opens purge VSV. EVAP discharge volume to intake manifold controlled by purge VSV duty cycle ratio (current-carrying time). (Open: ON, Closed: OFF) Refueling valve Controls EVAP pressure from fuel tank to canister. Valve consists of diaphragm, spring and restrictor (diameter: 0.08 inch). When fuel vapor and pressure inside fuel tank increase, valve opens. While EVAP purged, valve closes and restrictor prevents large amount of vacuum from affecting pressure in fuel tank. Valve opened while refueling. Roll-over valve Located in fuel tank. Valve closed by its own weight when vehicle overturns to prevent fuel from spilling out. Soak timer Built into ECM. To ensure accurate EVAP monitor, measures 5 hours (+/- 15 min) after ignition switch turned off. This allows fuel to cool down, stabilizing EVAP pressure. When approximately 5 hours elapsed, ECM activates (Scheme 139) Canister pump module Consists of (a) to (d) below. Canister pump module cannot be disassembled. (a) Vent valve Vents and closes EVAP system. When ECM turns valve ON, EVAP system closed. When, ECM turns valve OFF, EVAP system vented. Negative pressure (vacuum) created in EVAP system to check for EVAP leaks by closing purge VSV, turning on vent valve (closed) and operating leak detection pump (Scheme 137) (b) Canister pressure sensor Indicates pressure as voltages. ECM supplies regulated 5 V to canister pressure sensor, and uses feedback from sensor to monitor EVAP system pressure (Scheme 138) (c) Leak detection pump Creates negative pressure (vacuum) in EVAP system for leak check. (d) Reference orifice Has opening with 0.02 inch diameter. Vacuum produced through orifice by closing purge VSV, turning off vent valve and operating leak detection pump, to monitor reference pressure. Reference pressure indicates small leak of EVAP.

Scheme 156

When the ignition switch is turned to ON, the battery voltage is applied to the IGSW of the ECM. The output signal from the MREL terminal of the ECM causes a current to flow to the coil, closing the contacts of the integration relay (EFI relay) and supplying power to terminals +B and +B2 of the ECM.

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1. INSPECT INTEGRATION NO. 1 RELAY (POWER SOURCE OF INTEGRATION RELAY) Remove the integration relay from the engine room relay block. Measure the voltage between the terminal of the integration relay and body ground. Standard voltage Tester Connections Specified Conditions Engine room relay block (1C-1) - Body ground 11 to 14 V Reinstall the integration relay. NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR (BATTERY - INTEGRATION RELAY) OK: Go to next step
2. INSPECT INTEGRATION NO. 1 RELAY (EFI RELAY AND IG2 RELAY) Remove the integration relay from the engine room relay block. Inspect the EFI fuse and the AM2 fuse. Remove the EFI fuse and AM2 fuse from the integration relay. Check the resistance of the EFI fuse and AM2 fuse. Standard resistance Below 1 ohms Reinstall the EFI fuse and the AM2 fuse. Inspect the EFI relay and the IG2 relay. Check the resistance between the terminals shown below. Standard resistance Tester Connections Specified Conditions 1C-1 - 1A-4 10 kohms or higher Below 1 ohms (when battery voltage is applied to terminals 1A-2 and 1A-3) 1C-1 - 1B-4 10 kohms or higher Below 1 ohms (when battery voltage is applied to terminals 1B-2 and 1B-3) 1C-1 - 1B-1 Below 1 ohms Reinstall the integration relay. NG --> REPLACE INTEGRATION NO. 1 RELAY OK: Go to next step
3. CHECK HARNESS AND CONNECTOR (+B, +B2 AND MREL CIRCUIT) Check the harness and the connectors between the integration relay and the ECM. Remove the integration relay from the engine room relay block. Disconnect the A21 ECM connector. Check the resistance. Standard resistance (Check for open) Tester Connections Specified Conditions MREL (A21-44) - Engine room relay block (1A-2) Below 1 ohms +B (A21-2) - Engine room relay block (1A-4) +B2 (A21-1) - Engine room relay block (1A-4) Standard resistance (Check for short) Tester Connections Specified Conditions MREL (A21-44) or Engine room relay block (1A-2) - Body ground 10 kohms or higher +B (A21-2) or Engine room relay block (1A-4) - Body ground +B2 (A21-1) or Engine room relay block (1A-4) - Body ground Check the harness and the connector between the integration relay and body ground. Check the resistance. Standard resistance (Check for open) Tester Connections Specified Conditions Engine room relay block (1A-3) - Body ground Below 1 ohms Reinstall the integration relay. Reconnect the ECM connector. NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
4. CHECK HARNESS AND CONNECTOR (ECM - BODY GROUND) Disconnect the C20 ECM connector. Check the resistance. Standard resistance (Check for open) Tester Connections Specified Conditions E1 (C20-104) - Body ground Below 1 ohms Reconnect the ECM connector. NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
5. INSPECT ECM (IGSW VOLTAGE) Disconnect the C20 and A21 ECM connectors. Turn the ignition switch to ON. Measure the voltage between the terminals of the C20 and A21 ECM connectors. Standard voltage Tester Connections Specified Conditions IGSW (A21-28) - E1 (C20-104) 11 to 14 V Reconnect the ECM connectors. OK --> See step 10 NG: Go to next step
6. INSPECT FUSE (IGN FUSE) Remove the IGN fuse from the main body ECU. Check the IGN fuse resistance. Standard resistance Below 1 ohms Reinstall the IGN fuse. NG --> CHECK FOR SHORTS IN ALL HARNESSES AND CONNECTORS CONNECTED TO FUSE AND REPLACE FUSE OK: Go to next step
7. CHECK HARNESS AND CONNECTOR (INTEGRATION RELAY - ECM) Remove the integration relay from the engine room relay block. Disconnect the A21 ECM connector. Check the resistance. Standard resistance (Check for open) Tester Connections Specified Conditions Engine room relay block (1B-4) - IGSW (A21-28) Below 1 ohms Standard resistance (Check for short) Tester Connections Specified Conditions Engine room relay block (1B-4) or IGSW (A21-28) - Body ground 10 kohms or higher Reinstall the integration relay. Reconnect the ECM connector. NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
8. CHECK HARNESS AND CONNECTOR (INTEGRATION RELAY - IGNITION SWITCH) Check the harness and the connectors between the integration relay and the ignition switch. Remove the integration relay from the engine room relay block. Disconnect the D8 ignition switch connector. Check the resistance. Standard resistance (Check for open) Tester Connections Specified Conditions Engine room relay block (1B-2) - IG2 (D8-6) Below 1 ohms Standard resistance (Check for short) Tester Connections Specified Conditions Engine room relay block (1B-2) or IG2 (D8-6) - Body ground 10 kohms or higher Check the harness and the connectors between the integration relay and body ground. Check the resistance. Standard resistance (Check for open) Tester Connections Specified Conditions Engine room relay block (1B-3) - Body ground Below 1 ohms Reinstall the integration relay. Reconnect the ignition switch connector. NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
9. INSPECT IGNITION SWITCH Disconnect the D8 ignition switch connector. Check the resistance between the terminals shown below. Standard resistance Key Positions Tester Connections Specified Conditions LOCK - 10 kohms or higher ACC 2-4 Below 1 ohms ON 1-2-4 5-6 START 1-3-4 5-6-7 Reconnect the ignition switch connector. NG --> REPLACE IGNITION SWITCH OK --> REPAIR OR REPLACE HARNESS OR CONNECTOR (IGNITION SWITCH - INTEGRATION RELAY)
10. REPLACE ECM. Refer to «REMOVAL»(ref-394514-S02889335332011040800000)

The ECM constantly generates 5 V power from the battery voltages supplied to the +B (BATT) terminal to operate the microprocessor. The ECM also provides this power to the sensors through the VC output circuit.

Scheme 167

When the VC circuit is short-circuited, the microprocessor in the ECM and sensors that are supplied with power through the VC circuit are inactivated because the power is not supplied from the VC circuit. Under this condition, the system does not start up and the MIL does not illuminate even if the system malfunctions.

HINT

Under normal conditions, the MIL is illuminated for several seconds when the ignition switch is first turned to ON. The MIL goes off when the engine is started.

Scheme 168

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1. CHECK MIL Check that Malfunction Indicator Lamp (MIL) lights up when turning the ignition switch ON. OK MIL lights up OK --> See step 7 NG: Go to next step
2. CHECK COMMUNICATION BETWEEN TESTER AND ECM Connect a Techstream to the DLC3. Turn the ignition switch to ON. Turn the Techstream on. Check the communication between the Techstream and ECM. Result Result Proceed To Communication is possible A Communication is not possible B A --> See step 8 B: Go to next step
3. CHECK MIL (THROTTLE POSITION SENSOR) Disconnect the C17 throttle body connector. Turn the ignition switch to ON. Check the MIL. Result Result Proceed To MIL illuminates A MIL does not illuminate B Reconnect the throttle body connector. A --> See step 9 B: Go to next step
4. CHECK MIL (ACCELERATOR PEDAL POSITION SENSOR) Disconnect the A20 accelerator pedal position sensor connector. Turn the ignition switch to ON. Check the MIL. Result Result Proceed To MIL illuminates A MIL does not illuminate B Reconnect the accelerator pedal position sensor connector. A --> See step 10 B: Go to next step
5. CHECK MIL (CANISTER PUMP MODULE) Disconnect the J25 canister pump module connector. Turn the ignition switch to ON. Check the MIL. Result Result Proceed To MIL illuminates A MIL does not illuminate B Reconnect the canister pump module connector. A --> See step 11 B: Go to next step
6. CHECK HARNESS AND CONNECTOR (ECM - EACH SENSOR) Disconnect the C17 throttle body connector. Disconnect the A20 accelerator pedal position sensor connector. Disconnect the J25 canister pump module connector. Disconnect the A21 and C20 ECM connectors. Check the resistance. Standard resistance (Check for short) Tester Connections Specified Conditions VCTA (C20-67) - Body ground 10 kohms or higher VCPA (A21-57) - Body ground VCP2 (A21-58) - Body ground VCPP (C20-70) - Body ground Reconnect the throttle body connector. Reconnect the accelerator pedal position sensor connector. Reconnect the canister pump module connector. Reconnect the ECM connectors. NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK --> See step 12
7. PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE. Refer to «PROBLEM SYMPTOMS TABLE»(ref-394513-S40102418182011040800000)
8. GO TO MIL CIRCUIT. Refer to «MIL Circuit»(ref-394517-S09952225892011040800000)
9. REPLACE THROTTLE BODY. Refer to «REMOVAL»(ref-394514-S36129749062011040800000)
10. REPLACE ACCELERATOR PEDAL. Refer to «REMOVAL»(ref-394514-S08900300282011040800000)
11. REPLACE CANISTER. Refer to «REMOVAL»(ref-394509-S36487460012011040800000)
12. REPLACE ECM. Refer to «REMOVAL»(ref-394514-S02889335332011040800000)

When the engine is cranked, the starter relay drive signal output from the STAR terminal of the ECM is input into the STA terminal of the ECM, and NE signal generated by the crankshaft position sensor is also input into the NE+ terminal. Thus, the ECM interprets that the engine is cranked, and turns the transistor Tr1 in the ECM internal circuit ON. The current flows to the C/OPN (Circuit Opening) relay by turning the Tr1 ON. Then, the fuel pump operates.

While the NE signal is input into the ECM, when engine is running, the ECM turns the Tr1 on continuously.

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1. PERFORM ACTIVE TEST USING TECHSTREAM (CONTROL THE FUEL PUMP/SPEED) Connect a Techstream to the DLC3. Turn the ignition switch to ON. Turn the Techstream on. Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Fuel Pump/Speed. Check whether the fuel pump operating sound occurs when perform the Active Test on the Techstream. OK Fuel pump operating sound occurs. OK --> See step 8 NG: Go to next step
2. INSPECT MAIN BODY ECU (C/OPN RELAY INPUT VOLTAGE) Measure the voltage between the terminal of the main body ECU and the body ground when the ignition switch is turned to ON and OFF. Standard voltage Tester Connections Switch Conditions Specified Conditions 4B-11 - Body ground Ignition switch off Below 1 V 4F-4 - Body ground 4B-11 - Body ground Ignition switch ON 11 to 14 V 4F-4 - Body ground OK --> See step 4 NG: Go to next step
3. CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - INTEGRATION RELAY) Remove the integration relay from the engine room relay block. Disconnect the main body ECU connector. Check the resistance. Standard resistance (Check for open) Tester Connections Specified Conditions 1B-4 - 4F-4 Below 1 ohms 1A-4 - 4B-11 Standard resistance (Check for short) Tester Connections Specified Conditions 4F-4 - Body ground 10 kohms or higher 4B-11 - Body ground Reinstall the integration relay. Reconnect the main body ECU connector. NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK --> See step 10
4. INSPECT MAIN BODY ECU (C/OPN RELAY) Remove the main body ECU. Check the C/OPN relay resistance. Standard resistance Tester Connections Specified Conditions 4B-11 - 4A-8 10 kohms or higher Below 1 ohms (when battery voltage is applied to terminals 4D-1 and 4E-5) HINT: Relay coil circuit between 4D-1 and 4E-5 is not through IGN fuse. Reinstall the main body ECU. NG --> REPLACE MAIN BODY ECU OK: Go to next step
5. CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - ECM) Disconnect the A21 ECM connector. Disconnect the 4E connector from main body ECU. Check the resistance. Standard resistance (Check for open) Tester Connections Specified Conditions Main Body ECU (4E-5) - FC (A21-7) Below 1 ohms Standard resistance (Check for short) Tester Connections Specified Conditions Main body ECU (4E-5) or FC (A21-7) - Body ground 10 kohms or higher Reconnect the main body ECU and the ECM connectors. NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
6. CHECK HARNESS AND CONNECTOR (C/OPN RELAY - FUEL PUMP - BODY GROUND) Check the harness and the connectors between the main body ECU and the fuel pump. Disconnect the 4A main body ECU connector. Disconnect the J5 fuel pump connector. Check the resistance. Standard resistance (Check for open) Tester Connections Specified Conditions Main body ECU (4A-8) - Fuel pump (J5-4) Below 1 ohms Standard resistance (Check for short) Tester Connections Specified Conditions Main body ECU (4A-8) or Fuel pump (J5-4) - Body ground 10 kohms or higher Check the harness and the connectors between the fuel pump and the body ground. Disconnect the J5 fuel pump connector. Check the resistance. Standard resistance (Check for open) Tester Connections Specified Conditions Fuel pump (J5-5) - Body ground Below 1 ohms Reconnect the main body ECU connector. Reconnect the fuel pump connector. NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
7. INSPECT FUEL PUMP Inspect fuel pump resistance. Measure the resistance between the terminals. Standard resistance 0.2 to 3.0 ohms at 20°C (68°F) Inspect fuel pump operation. Apply the battery voltage to both the terminals. Check that the pump operates. NOTE: These tests must be done quickly (within 10 seconds) to prevent the coil from burning out. Keep the fuel pump as far away from the battery as possible. Always switch at the battery side. NG --> See step 11 OK --> See step 12
8. READ VALUE USING TECHSTREAM (STARTER SIGNAL) Connect the Techstream to the DLC3. Turn the ignition switch to ON. Turn the Techstream on. Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / Starter Signal. Check the result when the ignition switch is turned to ON and START. OK Ignition Switch Position Starter Signal ON OFF START ON NG --> See step 13 OK: Go to next step
9. READ VALUE USING TECHSTREAM (ENGINE SPEED) Connect the Techstream to the DLC3. Turn the ignition switch to ON. Turn the Techstream on. Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / Engine Speed. Read the values displayed on the Techstream while cranking. OK Values are displayed continuously. NG --> See step 14 OK --> See step 15
10. GO TO ECM POWER SOURCE CIRCUIT. Refer to «ECM Power Source Circuit»(ref-394517-S06537814052011040800000)
11. REPLACE FUEL PUMP. Refer to «REMOVAL»(ref-394522-S39993543732011040800000)
12. REPLACE ECM. Refer to «REMOVAL»(ref-394514-S02889335332011040800000)
13. REPAIR OR REPLACE STARTING SYSTEM. Refer to «Cranking Holding Function Circuit»(ref-394517-S37742305182011040800000)
14. REPAIR OR REPLACE CRANKSHAFT POSITION SENSOR CIRCUIT. Refer to «DTC P0335: Crankshaft Position Sensor "A" Circuit; DTC P0339: Crankshaft Position Sensor "A" Circuit Intermittent»(ref-394516-S15830363852011040800000)
15. REPLACE ECM. Refer to «REMOVAL»(ref-394514-S02889335332011040800000)

The fuel injectors are located on the intake manifold. They inject fuel into the cylinders based on the signals from the ECM.

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1. INSPECT FUEL INJECTOR (POWER SOURCE) Disconnect the fuel injector connectors. Turn the ignition switch to ON. Measure the voltage according to the value(s) in the table below. Standard voltage Tester Connections Specified Conditions C4-1 - Body ground 11 to 14 V C5-1 - Body ground 11 to 14 V C6-1 - Body ground 11 to 14 V C7-1 - Body ground 11 to 14 V Reconnect the fuel injector connectors. NG --> See step 6 OK: Go to next step
2. INSPECT FUEL INJECTOR (INJECTOR RESISTANCE) Disconnect the fuel injector connectors. Measure the resistance according to the value(s) in the table below. Standard resistance Tester Connections Specified Conditions 1 - 2 11.6 to 12.4 ohms at 20°C (68°F) Reconnect the fuel injector connectors. NG --> See step 9 OK: Go to next step
3. CHECK HARNESS AND CONNECTOR (FUEL INJECTOR - ECM) Disconnect the C20 ECM connector. Disconnect the fuel injector connectors. Measure the resistance according to the value(s) in the table below. Standard resistance (Check for open) Tester Connections Specified Conditions C4-2 - C20-108 (#10) Below 1 ohms C5-2 - C20-107 (#20) Below 1 ohms C6-2 - C20-106 (#30) Below 1 ohms C7-2 - C20-105 (#40) Below 1 ohms Standard resistance (Check for short) Tester Connections Specified Conditions C4-2 or C20-108 (#10) - Body ground 10 kohms or higher C5-2 or C20-107 (#20) - Body ground 10 kohms or higher C6-2 or C20-106 (#30) - Body ground 10 kohms or higher C7-2 or C20-105 (#40) - Body ground 10 kohms or higher Reconnect the fuel injector connectors. Reconnect the ECM connector. NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
4. CHECK HARNESS AND CONNECTOR (ECM - BODY GROUND) Disconnect the C20 ECM connector. Measure the resistance according to the value(s) in the table below. Standard resistance (Check for open) Tester Connections Specified Conditions C20-45 (E01) - Body ground Below 1 ohms C20-44 (E02) - Body ground Below 1 ohms Reconnect the ECM connector. NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
5. INSPECT FUEL INJECTOR (INJECTION AND VOLUME) Check the fuel injector injection and volume. Refer to «INSPECTION - Step 1»(ref-394522-S13876516432011040800000). NG --> See step 9 OK --> See step 8
6. CHECK HARNESS AND CONNECTOR (FUEL INJECTOR - INTEGRATION RELAY) Disconnect the fuel injector connectors. Remove the integration relay from the engine room relay block. Measure the resistance according to the value(s) in the table below. Standard resistance (Check for open) Tester Connections Specified Conditions C4-1 - 1B-4 (Integration relay) Below 1 ohms C5-1 - 1B-4 (Integration relay) Below 1 ohms C6-1 - 1B-4 (Integration relay) Below 1 ohms C7-1 - 1B-4 (Integration relay) Below 1 ohms Standard resistance (Check for short) Tester Connections Specified Conditions C4-1 or 1B-4 (Integration relay) - Body ground 10 kohms or higher C5-1 or 1B-4 (Integration relay) - Body ground 10 kohms or higher C6-1 or 1B-4 (Integration relay) - Body ground 10 kohms or higher C7-1 or 1B-4 (Integration relay) - Body ground 10 kohms or higher Reconnect the fuel injector connectors. Reinstall the integration relay. NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK --> See step 7
7. REPAIR OR REPLACE ECM POWER SOURCE CIRCUIT. Refer to «ECM Power Source Circuit»(ref-394517-S06537814052011040800000)
8. PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE. Refer to «PROBLEM SYMPTOMS TABLE»(ref-394513-S40102418182011040800000)
9. REPLACE FUEL INJECTOR. Refer to «REMOVAL»(ref-394522-S15591188762011040800000)

The cranking holding control system provides a current to the starter when the ECM detects the ignition switch's start signal (STSW). When the ECM judges that the engine has started, the system cuts the current to the starter. When the ECM receives the STSW signal, it turns on the ACC (Accessory) relay, which prevents flickering of the combination meter, clock and audio system. Also, the ECM sends a signal to the ECM's STAR terminal. Then the STAR output signal travels through the Park/Neutral Position (PNP) switch to the ST relay, causing the starter to activate. When the engine is cranking, the starter operation signal is sent to the ECM's STA terminal.

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1. READ VALUE USING TECHSTREAM (STARTER SIGNAL) Connect a Techstream to the DLC3. Turn the ignition switch to ON and turn the Techstream on. Turn the Techstream on. Enter the following menus: Powertrain / Engine and ECT / Engine and ECT / Data List / All Data / Starter Signal. Check the result when the ignition switch is turned to ON and START. OK Ignition Switch Position Starter Signal ON OFF START ON OK --> See step 12 NG: Go to next step
2. INSPECT ECM (STSW VOLTAGE) Disconnect the A21 ECM connector. Measure the voltage between the terminals of the ECM connector and body ground while cranking the engine. Standard voltage Tester Connections Specified Conditions STSW (A21-14) - Body ground 11 to 14 V Result Result Proceed To Within standard range(A/T) A Within standard range (M/T) B Outside standard range C Reconnect the ECM connector. C --> See step 9 B --> See step 6 A: Go to next step
3. INSPECT ECM (STAR VOLTAGE) Disconnect the C27 Park/Neutral Position (PNP) switch connector. Measure the voltage between the terminals of the PNP switch connector and body ground while cranking the engine. Standard voltage Tester Connections Specified Conditions B (C27-4) - Body ground 11 to 14 V Reconnect the PNP switch connector. NG --> See step 10 OK: Go to next step
4. INSPECT PARK/NEUTRAL POSITION SWITCH Disconnect the C27 PNP switch connector. Check the resistance between each terminal shown below when the shift lever is moved to each range. Standard resistance Shift Position Tester Connections Specified Conditions P PL (6) - RB (2) Below 1 ohms L (5) - B (4) R RL (1) - RB (2) N NL (9) - RB (2) L (5) - B (4) D DL (7) - RB (2) 2 2L (3) - RB (2) L LL (8) - RB (2) Reconnect the PNP switch connector. NG --> See step 15 OK: Go to next step
5. CHECK HARNESS AND CONNECTOR (PARK/NEUTRAL POSITION SWITCH - ECM) Disconnect the C27 PNP switch connector. Disconnect the A21 ECM connector. Check the resistance. Standard resistance (Check for open) Tester Connections Specified Conditions L (C27-5) - STA (A21-48) Below 1 ohms Standard resistance (Check for short) Tester Connections Specified Conditions L (C27-5) or STA (A21-48) - Body ground 10 kohms or higher Reconnect the PNP switch connector. Reconnect the ECM connector. NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK --> See step 16
6. INSPECT ECM (STAR VOLTAGE) Disconnect the A16 clutch start switch connector. Measure the voltage between the terminals of the clutch start switch connector and body ground while cranking the engine. Standard voltage Tester Connections Specified Conditions B (A16-2) - Body ground 11 to 14 V Reconnect the clutch start switch connector. NG --> See step 11 OK: Go to next step
7. INSPECT CLUTCH START SWITCH Disconnect the A16 clutch start switch connector. Check the resistance between the terminals of the clutch start switch. Standard resistance Switch Positions Specified Conditions Pushed in Below 1 ohms Released 10 kohms or higher Reconnect the clutch start switch connector. NG --> See step 17 OK: Go to next step
8. CHECK HARNESS AND CONNECTOR (CLUTCH START SWITCH - ECM) Disconnect the A16 clutch start switch connector. Disconnect the A21 ECM connector. Check the resistance. Standard resistance (Check for open) Tester Connections Specified Conditions L (A16-1) - STA (A21-48) Below 1 ohms Standard resistance (Check for short) Tester Connections Specified Conditions L (A16-1) or STA (A21-48) - Body ground 10 kohms or higher Reconnect the clutch start switch connector. Reconnect the ECM connector. NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK --> See step 18
9. INSPECT IGNITION SWITCH Disconnect the D8 ignition switch connector. Check the resistance between the terminals shown below. Standard resistance Key Positions Tester Connections Specified Conditions LOCK - 10 kohms or higher ACC 2 - 4 Below 1 ohms ON 1 - 2 - 4 5 - 6 START 1 - 3 - 4 5 - 6 - 7 Reconnect the ignition switch connector. NG --> See step 19 OK --> REPAIR OR REPLACE HARNESS OR CONNECTOR (ECM - IGNITION SWITCH - BATTERY)
10. CHECK HARNESS AND CONNECTOR (IGNITION SWITCH - PARK/NEUTRAL POSITION SWITCH - ECM) Disconnect the D8 ignition switch connector. Disconnect the C27 PNP switch connector. Disconnect the C20 ECM connector. Check the resistance. Standard resistance (Check for open) Tester Connections Specified Conditions ST2 (D8-7) - B (C27-4) Below 1 ohms STAR (C20-52) - B (C27-4) STAR (C20-52) - L (C27-5) Standard resistance (Check for short) Tester Connections Specified Conditions ST2 (D8-7) or B (C27-4) - Body ground 10 kohms or higher STAR (C20-52) or B (C27-4) - Body ground STAR (C20-52) or L (C27-5) - Body ground Reconnect the ignition switch connector. Reconnect the PNP switch connector. Reconnect the ECM connector. NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK --> See step 20
11. CHECK HARNESS AND CONNECTOR (IGNITION SWITCH - CLUTCH START SWITCH - ECM) Disconnect the D8 ignition switch connector. Disconnect the A16 clutch start switch connector. Disconnect the C20 ECM connector. Check the resistance. Standard resistance (Check for open) Tester Connections Specified Conditions ST2 (D8-7) - B (A16-2) Below 1 ohms STAR (C20-52) - B (A16-2) STAR (C20-52) - L (A16-1) Standard resistance (Check for short) Tester Connections Specified Conditions ST2 (D8-7) or B (A16-2) - Body ground 10 kohms or higher STAR (C20-52) or B (A16-2) - Body ground STAR (C20-52) or L (A16-1) - Body ground Reconnect the ignition switch connector. Reconnect the clutch start switch connector. Reconnect the ECM connector. NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK --> See step 21
12. INSPECT BATTERY Check that the battery is not depleted. OK Battery is not depleted. NG --> REPLACE BATTERY OK: Go to next step
13. CHECK BATTERY TERMINAL Check that the battery terminals are not loose or corroded. OK Battery terminals are not loose or corroded. NG --> REPAIR OR REPLACE BATTERY TERMINAL OK: Go to next step
14. CHECK HARNESS AND CONNECTOR (PNP SWITCH OR CLUTCH START SWITCH - ST RELAY) Remove the ST relay from the engine room relay block. Disconnect the C27 PNP switch connector (A/T). Disconnect the A16 clutch start switch connector (M/T). Check the resistance. Standard resistance (Check for open) Tester Connections Specified Conditions L (C27-5) - ST relay (2) Below 1 ohms L (A16-1) - ST relay (2) ST relay (1) - Body ground Standard resistance (Check for short) Tester Connections Specified Conditions L (C27-5) or ST relay (2) - Body ground 10 kohms or higher L (A16-1) or ST relay (2) - Body ground Reinstall the ST relay. Reconnect the PNP switch connector (A/T). Reconnect the clutch start switch connector (M/T). NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK --> CHECK AND REPLACE STARTER RELAY AND STARTER
15. REPLACE PARK / NEUTRAL POSITION SWITCH. Refer to «REMOVAL»(ref-394505-S07185985642011040800000)
16. REPLACE ECM. Refer to «REMOVAL»(ref-394514-S02889335332011040800000)
17. REPLACE CLUTCH START SWITCH. Refer to «REMOVAL»(ref-394520-S37004663362011040800000)
18. REPLACE ECM. Refer to «REMOVAL»(ref-394514-S02889335332011040800000)
19. REPLACE IGNITION SWITCH. Refer to «REMOVAL»(ref-394519-S11486970352011040800000)
20. REPLACE ECM. Refer to «REMOVAL»(ref-394514-S02889335332011040800000)
21. REPLACE ECM. Refer to «REMOVAL»(ref-394514-S02889335332011040800000)

The MIL (Malfunction Indicator Lamp) is used to indicate vehicle malfunction detections by the ECM. When the ignition switch is turned to ON, power is supplied to the MIL circuit, and the ECM provides the circuit ground which illuminates the MIL.

The MIL operation can be checked visually: When the ignition switch is first turned to ON, the MIL should be illuminated and should then turn off. If the MIL remains illuminated or is not illuminated, conduct the following troubleshooting procedure using a Techstream.

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1. CHECK THAT MIL IS ILLUMINATED Perform troubleshooting in accordance with the table below. Result Result Proceed To MIL remains ON A MIL does not illuminate B B --> See step 5 A: Go to next step
2. CHECK WHETHER MIL TURNS OFF Connect a Techstream to the DLC3. Turn the ignition switch to ON. Turn the Techstream on. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes. Check if any DTCs have been stored. Note down any DTCs. Result Result Proceed To No DTC detected A Any DTC detected B B --> See step 8 A: Go to next step
3. CHECK HARNESS AND CONNECTOR (CHECK FOR SHORT IN WIRE HARNESS) Disconnect the A21 ECM connector. Turn the ignition switch to ON. Check that the MIL is not illuminated. OK MIL is not illuminated. Reconnect the ECM connector. OK --> See step 9 NG: Go to next step
4. CHECK HARNESS AND CONNECTOR (COMBINATION METER - ECM) Disconnect the A21 ECM connector. Disconnect the D2 combination meter connector (for Hatchback). Disconnect the D76 combination meter connector (for Sedan). Check the resistance. Standard resistance (Check for short) Tester Connections Specified Conditions W (A21-24) or combination meter (D2-4) - Body ground 10 kohms or higher W (A21-24) or combination meter (D76-4) - Body ground Reconnect the ECM connector. Reconnect the combination meter connector. NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK --> REPAIR OR REPLACE COMBINATION METER ASSEMBLY
5. CHECK THAT MIL IS ILLUMINATED Check if the MIL is illuminated when the ignition switch is turned to ON. OK MIL should be illuminated. NG --> See step 6 OK --> See step 10
6. CHECK THAT ENGINE STARTS Turn the ignition switch to ON. Start the engine. Result Proceed To Engine starts A Engine does not start* B HINT: *: A Techstream cannot communicate with the ECM. B --> See step 11 A: Go to next step
7. INSPECT COMBINATION METER ASSEMBLY (MIL CIRCUIT) Check the MIL circuit for Hatchback. Refer to «TERMINALS OF ECU»(ref-394532-S42428639322011040800000). Check the MIL circuit for Sedan. Refer to «TERMINALS OF ECU»(ref-394533-S37313288852011040800000). NG --> REPAIR OR REPLACE COMBINATION METER ASSEMBLY OK --> CHECK AND REPLACE HARNESS OR CONNECTOR (COMBINATION METER - ECM)
8. REPAIR CIRCUITS INDICATED BY OUTPUT DTCS. Refer to «DIAGNOSTIC TROUBLE CODE CHART»(ref-394513-S31071923012011040800000)
9. REPLACE ECM. Refer to «REMOVAL»(ref-394514-S02889335332011040800000)
10. CHECK FOR INTERMITTENT PROBLEMS. Refer to «CHECK FOR INTERMITTENT PROBLEMS»(ref-394513-S06690205932011040800000)
11. GO TO VC OUTPUT CIRCUIT. Refer to «VC Output Circuit»(ref-394517-S22936321042011040800000)

See also:
• ON-VEHICLE INSPECTION
• ON-VEHICLE INSPECTION - Step 2
• ON-VEHICLE INSPECTION
• ON-VEHICLE INSPECTION - Step 8
• PARTS LOCATION