Part 1
ENGINE CONTROL SYSTEM OPERATION INSPECTION[AJ]Input Signal System Investigation Procedure
1. Find an unusual signal.
2. Locate its source.
3. Repair or replace the detective part.
4. Confirm that the unusual signal has been erased.
Finding unusual signals
While referring to ON-BOARD DIAGNOSTIC TEST[AJ], use the PID/DATA monitor and record function to inspect the input signal system relating to the problem.
1. Start the engine and idle the vehicle. You can assume that any signals that are out of specification by a wide margin are unusual.
2. When recreating the problem, any sudden change in monitor input signals that is not consciously created by the driver can be judged as unusual.
Locating the source of unusual signals
CAUTION:
- Compare the M-MDS monitor voltage with the measurement voltage using the digital measurement system function. If you use another tester; misreading may occur.
- When measuring voltage, attach the tester GND to the GND of the PCM that is being tested, or to the engine itself. If this is not done, the measured voltage and actual voltage may differ.
- After connecting the pin to a waterproof coupler; confirming continuity and measuring the voltage, inspect the waterproof connector for cracks. If there are any, use sealant to fix them. Failure to do this may result in deterioration of the harness or terminal from water damage, leading to problems with the vehicle.
Variable resistance type 1 (APP sensor, TP sensor and EGR boost sensor)
Investigate the input signal system for variable resistance type 1
1. When you get an unusual signal, measure the #1 PCM terminal voltage.
- If the #1 terminal voltage and the M-MDS monitor voltage are the same, proceed to the next step.
- If there is a difference of 0.5 V or more, inspect for the following points concerning the PCM connector.
- Female terminal opening is loose.
- Coupler (pin holder) damage
- Pin discoloration (blackness)
- Harness/pin crimp is loose or disconnected.
2. Measure the #2 sensor terminal voltage.
- If there is a 0.5 V or more difference between the sensor and M-MDS voltages, inspect the harness for open or short circuits.
- If the sensor and M-MDS voltages are the same, inspect for the following points concerning the sensor connector.
- If there are no problems, proceed to next investigation below.
- Female terminal opening is loose.
- Coupler (pin holder) damage
- Pin discoloration (blackness)
Investigate the standard power supply system for variable resistance type 1
- Confirm that the #3 terminal is at 5 V.
- It the measured voltage on the #3 terminal is 5 V, inspect the following points on the sensor connector.
- If there is no problem, inspect for the following:
- Female terminal opening loose
- Coupler (pin holder) damage
- Pin discoloration (blackness)
- It the #3 terminal measures other than 5 V, inspect for the following:
- Open or short circuit in harness
- Harness/pin crimp is loose or disconnected.
Investigate the GND system for variable resistance type 1
- Confirm that terminal sensor #5 is at 0 V.
- If it is at 0 V, inspect the sensor.
- If necessary, replace the sensor.
- If not, inspect for the following:
- Open or short circuit in harness
- Female terminal opening is loose open or short circuit in harness
- Coupler (pin holder) damage
- Pin discoloration (blackness)
- Harness/pin crimp is loose or disconnected.
Variable resistance type 2 (MAF sensor)
Investigate the GND system for variable resistance type 2
- Confirm that terminal sensor #4 is at 0 V.
- If it is at 0 V, inspect the sensor.
- If necessary, replace the sensor.
- If not at 0 V, inspect for the following:
- Open circuit in harness
- Female terminal opening is loose.
- Coupler (pin holder) damage
- Pin discoloration (blackness)
- Harness/pin crimp is loose or disconnected.
Investigate the input signal system for variable resistance type 2
1. When you get an unusual signal, measure the #1 PCM terminal voltage.
- If the #1 terminal voltage and the M-MDS monitor voltage are the same, proceed to the next step.
- If there is a difference of 0.5 V or more, inspect for the following points concerning the PCM connector.
- Female terminal opening is loose.
- Coupler (pin holder) damage
- Pin discoloration (blackness)
- Harness/pin crimp is loose or disconnected.
2. Measure the #2 sensor terminal voltage.
- If there is a 0.5 V or more difference between the sensor and M-MDS voltages, inspect the harness for open or short circuits.
- If the sensor and M-MDS voltages are the same, inspect the following points concerning the sensor connector.
- Female terminal opening is loose.
- Coupler (pin holder) damage
- Pin discoloration (blackness)
- Harness/pin crimp is loose or disconnected.
- If there are no problems, proceed to next investigation below.
Investigate the electrical supply system for variable resistance type 2
- Confirm that the sensor #3 terminal is B+.
- It the measured voltage on the #3 terminal is B+, inspect the following points on the sensor connector.
- If there is no problem, inspect for the following:
- Female terminal opening is loose.
- Coupler (pin holder) damage
- Pin discoloration (blackness)
- If the #3 terminal measures other than B+, inspect the following:
- Open or short circuit in harness
- Harness/pin crimp is loose or disconnected.
Thermistor type (IAT sensor and ECT sensor)
Investigate the input signal system for thermistor type
1. When you get an unusual signal, measure the #1 PCM terminal voltage.
- If the #1 terminal voltage and the M-MDS monitor voltage are the same, proceed to the next step.
- If there is a difference of 0.5 V or more, inspect the following points concerning the PCM connector.
- Female terminal opening loose
- Coupler (pin holder) damage
- Pin discoloration (blackness)
- Harness/pin crimp is loose or disconnected.
2. Measure the #2 sensor terminal voltage.
- If there is a 0.5 V or more difference between the sensor and M-MDS voltages, inspect the harness for open or short circuits.
- If the sensor and M-MDS voltages are the same, inspect the following points concerning the sensor connector.
- Female terminal opening is loose.
- Coupler (pin holder) damage
- Pin discoloration (blackness)
- Harness/pin crimp is loose or disconnected.
- If there are no problems, proceed to next investigation below.
Investigate the GND system for thermistor type
- Confirm that terminal sensor #3 is at 0 V.
- If it is at 0 V, inspect the sensor. If necessary, replace the sensor.
- If not, inspect for the following:
- Open circuit in harness
- Female terminal opening is loose.
- Coupler (pin holder) damage
- Pin discoloration (blackness)
- Harness/pin crimp is loose or disconnected.
1. Measure the #1 PCM terminal voltage and confirm that it is at 0 V or 5 V when the ignition switch at ON position and the engine at idle.
- If it is at 0 V or 5 V, intermittent concern exists. (See INTERMITTENT CONCERN TROUBLESHOOTING[AJ].) Intermittent Concern Troubleshooting
- If not, inspect the following points concerning the PCM connector.
- If there is no problem, inspect for the following:
- Female terminal opening is loose.
- Coupler (pin holder) damage
- Pin discoloration (blackness)
- Harness/pin crimp is loose or disconnected.
2. Measure the #2 sensor terminal voltage and confirm that it is at 0 V( or 5 V when the ignition switch at ON and the engine at idle.
- If it is at 0 V or 5 V, intermittent concern exists. (See INTERMITTENT CONCERN TROUBLESHOOTING[AJ].) Intermittent Concern Troubleshooting
- If not, inspect the following points concerning the sensor connector.
- If there is no problem, inspect for the following:
- Female terminal opening is loose.
- Coupler (pin holder) damage
- Pin discoloration (blackness)
- Harness/pin crimp is loose or disconnected.
3. Confirm that the #3 terminal switch voltage is at 0 V.
- If it is at 0 V, inspect the sensor. If necessary, replace the sensor.
- If necessary, replace the sensor.
- If not, inspect for the following:
- Open circuit in harness
- Female terminal opening is loose.
- Coupler (pin holder) damage
- Pin discoloration (blackness)
- Harness/pin crimp is loose or disconnected.
Main Relay Operation Inspection
1. Verify that the main relay clicks when the ignition switch is turned to ON position and off.
- If there is no operation sound, inspect the following:
- Main relay
- Harness and connector between ignition switch and main relay terminal A.
- Harness and connector between PCM terminal 1Z and main relay terminal E.
Intake Manifold Vacuum Inspection
1. Verify air intake hoses are installed properly.
2. Start the engine and run it at idle.
3. Measure the manifold vacuum using a vacuum gauge.
- If not as specified, inspect following:
- Air suction at throttle body, intake manifold and PCV valve installation points
- EGR valve (struck open)
- Fuel injector insulator
- Engine compression
NOTE: Air suction can be located by engine speed change when lubricant is sprayed on the area where suction occurs.
Electronic Throttle Control Inspection
Engine coolant temperature compensation inspection
1. Connect the M-MDS to the DLC-2.
2. Select the PID/DATA MONITOR AND RECORD function on the M-MDS display.
3. Select the following PIDs.
- ECT
- IAT
- RPM
4. Verify that the engine is in cold condition, then start the engine.
5. Verify that the engine speed decreases as the engine warm-up.
- If the engine speed does not decrease or decreases slowly, inspect the following:
- ECT sensor and related harness (See ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION[AJ].)
- Throttle body and related harness (See THROTTLE ACTUATOR INSPECTION[AJ].)Testing and Inspection (See THROTTLE POSITION (TP) SENSOR INSPECTION[AJ].)Testing and Inspection
Load compensation inspection
1. Start the engine and run is at idle.
2. Connect the M-MDS to the DLC-2.
3. Verify that P0506, P0507 or P0511 are not displayed.
- If P0506, P0507 or P0511 are displayed, perform DTC inspection. (See DTC TABLE[AJ].) Diagnostic Trouble Code Descriptions
4. Select the RPM PID.
NOTE: Excludes temporary idle speed drop just after the loads are fumed on.
5. Verify that the engine speed is within the specification.
- If not as specified at specific load condition, inspect the following:
- A/C switch and related harness
- Fan switch and related harness
- PSP switch and related harness
Throttle position (TP) sweep inspection
1. Connect the M-MDS to the DLC-2.
2. Turn ignition switch to ON position.
3. Verify that following DTCs are not displayed:
- P0121, P0122, P0123, P0221, P0222, P0223, P2100, P2101, P2102, P2103, P2107, P2108, P2119, P2122, P2123, P2127, P2128, P2135, P2136
- If any DTC is displayed, perform DTC inspection. (See DTC TABLE[AJ].) Diagnostic Trouble Code Descriptions
4. Access TP_REL PID.
5. Verify that the PID reading is within the CTP value. (See PCM INSPECTION[AJ].) Using M-MDS
- If the PID reading is out of range, perform the following:
- Remove air duct from throttle body.
- Verify that throttle valve moves when the accelerator pedal is depressed.
- If the throttle valve moves, inspect the following:
- TP sensor and related harness
- If the throttle valve does not move, inspect the following:
- Throttle actuator control motor and related harness
6. Gradually move the throttle valve and verify that the PID reading increases linearly.
- If the PID reading drops momentarily, inspect the following:
- TP sensor
7. Fully depress the accelerator pedal and verify that the PID reading is within the WOT value. (See PCM INSPECTION[AJ].) Using M-MDS
- If the PID reading is out of range, perform the following:
- Remove air duct from throttle valve body.
- Verify that the throttle valve moves when the accelerator pedal is depressed.
- If the throttle valve moves, inspect the TP sensor and related harness.
- If the throttle valve does not move, inspect the throttle actuator control motor and related harness.
Step 1-Step 4:
Fuel Cut Control System Inspection
1. Warm-up engine and let it idle.
2. Turn oft the electrical loads and A/C switch.
3. Connect the M-MDS to the DLC-2.
4. Select RPM PID.
5. Listen for the fuel injector operation sound at all cylinders using the sound scope and monitor PID while performing the following steps:
1. Depress the accelerator pedal and increase the engine speed to 4,000 rpm.
2. Quickly release the accelerator pedal (brake pedal is not depressed) and verity that the fuel injector operation sound stops when the accelerator pedal is released and starts again when the engine speed drops below 1,200 rpm.
- If not as specified, inspect the following:
- ECT sensor and related harness (See ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION[AJ].)Testing and Inspection
- Neutral/clutch switch and related harness (MTX) (See CLUTCH PEDAL POSITION (CPP) SWITCH INSPECTION[AJ].)Testing and Inspection
- TR switch and related harness (ATX) (See TRANSAXLE RANGE (TR) SWITCH INSPECTION[AW6A-EL].)
Fuel Pump Operation Inspection
CAUTION: Connecting the wrong check connector terminal may possibly cause malfunction. Carefully connect the specified terminal only.
1. Short the check connector terminal F/P to body GND using a jumper wire. (See AFTER REPAIR PROCEDURE[L3, AJ].) After Repair Procedure
2. Remove the fuel-filler cap.
3. Turn ignition switch to ON position.
4. Verify that the fuel pump operation sound is heard.
- If no operation sound is heard, proceed to next step.
5. Measure the voltage at harness side fuel pump connector terminal B.
Specification: B+ (Ignition switch at ON)
- If the voltage is as specified, inspect the following:
- Fuel pump continuity
- Fuel pump GND
- Wiring harness between fuel pump relay and PCM terminal 1v
- If not as specified, inspect the following:
- Fuel pump relay
- Wiring harness connector (Main relay-fuel pump relay-fuel pump)
Fuel Pump Control System Inspection
1. Crank the engine and verify that fuel pump relay operation sound is heard.
- If operation sound is not heard, inspect the following:
- Fuel pump relay
- Wiring harness and connectors (Main relay-fuel pump relay-PCM terminal 1 V)
2. It operation sound is not heard, inspect the following:
Ignition Timing Control Inspection
1. Start the engine and run it at idle.
2. Warm up the engine to normal operating temperature.
3. Connect the M-MDS to the DLC-2.
4. Select the PID/DATA MONITOR AND RECORD function on the M-MDS display.
5. Select the SPARKADV PID.
5. Verify that SPARKADV PID is within the specification. (See PCM INSPECTION[AJ].) Using M-MDS
7. Increase the engine speed and verify that the SPARKADV PID value is advanced.
- If it is not advanced, inspect the following:
- CKP sensor and related harness (See CRANKSHAFT POSITION (CKP) SENSOR INSPECTION[AJ].)
- MAF sensor and related harness (See MASS AIR FLOW (MAF) SENSOR INSPECTION[AJ].)Testing and Inspection
- CMP sensors (left and right bank) and related harness (See CAMSHAFT POSITION (CMP) SENSOR INSPECTION[AJ]Testing and Inspection
Spark Test
1. Disconnect the fuel pump relay.
2. Verify that each ignition connector is connected properly.
Step 1-Step 3:
Step 4-Step 7:
3. Inspect the ignition system in the following procedure:
WARNING: High voltage in the ignition system can cause strong electrical shock which can result in serious injury. Avoid direct contact to the vehicle body during the following spark test.
EGR Control System Inspection
1. Verify that EGR valve operation (initial operation) sound is heard when the ignition switch is turned to ON position.
- If the operation sound is not heard, connect M-MDS to the DLC-2 and verity that the DTC P0403 is shown. Perform DTC inspection. (See DTC TABLE[AJ].) Diagnostic Trouble Code Descriptions
2. Start the engine and run it at idle.
3. Warm-up the engine to normal operating temperature.
4. Select the following PIDs:
- ECT
- RPM
- SEGRP
- APP1
- APP2
- TP_REL
- VSS
5. Let the vehicle idle and verify that the SEGRP value is 0.
6. Put the vehicle in drive.
7. Depress the accelerator pedal and verify that the SEGRP value increases.
- If the SEGRP value does not increase, inspect the VSS, APP1, APP2, TP_REL and ECT PIDs. (See PCM INSPECTION[AJ].) Using M-MDS
- If the SEGRP value does increases, inspect the following:
- EGR valve (Stuck open or close)
- Wiring harness and connectors (Main relay-EGR valve-PCM)
8. Stop the vehicle and verity that the SEGRP value returns to 0.
Purge Control System Inspection
1. Start the engine.
2. Disconnect the vacuum hose between the purge solenoid valve and the charcoal canister.
3. Put a finger to the purge solenoid valve and verify that there is no vacuum applied when the engine is cold.
- If there is a vacuum, inspect the following:
- Wiring harness and connectors (Purge solenoid valve - PCM terminal 1 BF)
- Purge solenoid valve
4. Warm-up the engine to the normal operating temperature.
5. Stop the engine.
6. Connect the M-MDS to the DLC-2 and verify that the DTC P0443 is displayed. Perform DTC inspection. (See DTC TABLE[AJ].) Diagnostic Trouble Code Descriptions
7. Turn ignition switch to ON position.
8. Select ECT PID.
9. Verify that the engine coolant temperature is 60 °C {140 °F} or above.
- If M-MDS indicates less than 60 °C {140 °F}, perform the ECT sensor inspection. (See ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION[AJ].)
10. Set the vehicle on the dynamometer or chassis roller.
WARNING: When the dynamometer or chassis roller is operating, there is a possibility that the operator may come into contact with or be caught up in the rotating parts, leading to serious injuries or death. When performing work while the dynamometer or chassis roller is operating, be careful not to come into contact with or be caught up in any of the rotating parts.
11. Drive vehicle with engine speed at approx. 2,000 rpm for more than 30 s.
12. Put a finger to the purge solenoid valve and verify that there is no vacuum applied.
- If there is no vacuum, inspect the following:
- Wiring harness and connector (Main relay- purge solenoid valve-PCM terminal 1 BF)
- Purge solenoid valve
- MAF, APP1, APP2, TP_REL and LOAD PIDs
- If there is vacuum, inspect the following:
- Vacuum hose (Purge Solenoid valve - charcoal canister)