P0201
DTC P0201: Injector Circuit - Cylinder 1Injector Circuit-Cylinder 1 (Part 1):
Injector Circuit-Cylinder 1 (Part 2):
CIRCUIT OPERATION
- The injector power is supplied from the injector relay (terminal No. 3).
- The ECM controls the injector by turning the power transistor in the ECM "ON" and "OFF".
TECHNICAL DESCRIPTION
- The amount of fuel injected by the injector is controlled by the amount of continuity time the coil is grounded by the ECM.
DESCRIPTIONS OF MONITOR METHODS
The ECM detects open circuit and short malfunction.
MONITOR EXECUTION
Continuous
MONITOR EXECUTION CONDITIONS (Other monitor and Sensor)
Other Monitor (There is no temporary DTC stored in memory for the item monitored below)
- Not applicable
Sensor (The sensor below is determined to be normal)
- Not applicable
DTC SET CONDITIONS [Circuit continuity-open circuit and shorted low]
Logic Flow Chart:
Check Condition
- Engine is running.
Judgement Criterion
- The supply voltage is 3 volts or less without the injector driving for 2 seconds.
DTC SET CONDITIONS [Circuit continuity-shorted high] Logic Flow Chart
Logic Flow Chart:
Check Condition
- Engine is running.
Judgement Criterion
- The coil current is 4.5 ampere or more with the injector driving for 2 seconds.
OBD-II DRIVE CYCLE PATTERN
Refer to MFI Diagnostic Function-OBD-II Drive Cycle-Pattern 24. OBD-II Drive Cycle
TROUBLESHOOTING HINTS (The most likely causes for this code to be set are:)
- No. 1 cylinder injector failed.
- Connector damage.
- Harness damage.
- ECM failed.
DIAGNOSIS
Required Special Tools:
- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: V.C.I.
- MB991827: USB Cable
- MB991910: Main Harness A
- MB991658: Test Harness
- MB992110: Power Plant ECU Check Harness
STEP 1. Using scan tool MB991958, check actuator test item 1: No. 1 Injector.
CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
1. Connect scan tool MB991958 to the data link connector.
2. Start the engine and run at idle.
3. Set scan tool MB991958 to the actuator testing mode for item 1, No. 1 injector.
4. Warm up the engine to normal operating temperature: 80 °C to 95 °C (176 °F to 203 °F).
- The idle should become slightly rougher.
5. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the actuator operating properly?
YES : It can be assumed that this malfunction is intermittent. Refer to General (Body and Chassis), How to Use Troubleshooting/Inspection Service Points-How to Cope with Intermittent Malfunctions.
NO : Go to Step 2.
STEP 2. Check for harness connector B- 21 at the intermediate connector and B-10 at the ECM for damage.
Q: Is the harness connector in good condition?
YES : Go to Step 3.
NO : Repair it. Refer to General (Electrical), Harness Connector Inspection. Then go to Step 9.
STEP 3. Measure the injector supply voltage at the intermediate connector harness B-21 and ground.
1. Disconnect the intermediate connector B-21 and measure at the female connector side.
2. Turn the ignition switch to the "ON" position.
3. Measure the voltage between terminal No. 6 and ground.
- Voltage should be battery positive voltage.
4. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the measured resistance battery positive voltage?
YES : Go to Step 4.
NO : Check harness connector A-13 at intermediate connector for damage, and repair or replace as required. Refer to General (Electrical), Harness Connector Inspection. If intermediate connector is in good condition, repair harness wire between injector relay connector A-24X (terminal No. 3) and intermediate connector B-21 (terminal No. 6) because of open circuit. Then go to Step 9.
STEP 4. Check the No. 1 cylinder injector resistance at intermediate connector B-21.
1. Disconnect the intermediate connector B-21 and measure at male connector side.
2. Measure the resistance between terminal No. 6 and No. 7.
- Resistance should be between 10.5 and 13.5 ohms.
Q: Is the measured resistance between 10.5 and 13.5 ohms?
YES : Go to Step 7.
NO : Go to Step 5.
STEP 5. Check the harness connector B-101 at No. 1 cylinder injector for damage.
Remove the intake manifold.
Q: Is the harness connector in good condition?
YES : Go to Step 6.
NO : Repair it. Refer to General (Electrical), Harness Connector Inspection. Then go to Step 9.
STEP 6. Check the No. 1 cylinder injector B-101.
1. Disconnect the No. 1 cylinder injector connector B-101.
2. Measure the resistance between injector side connector terminal No. 1 and No. 2.
Standard value: 10.5-13.5 ohms [at 20 °C (68 °F)]
Q: Is the measured resistance between 10.5 and 13.5 ohms [at 20 °C (68 °F)]?
YES : Repair harness wire between the intermediate connector B-21 (terminal No. 6) and the injector connector B-101 (terminal No. 1) and harness wire between injector connector B-101 (terminal No. 2) and intermediate connector B-21 (terminal No. 7) because of open circuit or short circuit to ground or harness damage. Then go to Step 9.
NO : Replace the No. 1 cylinder injector. Then go to Step 9.
STEP 7. Check for harness between the intermediate connector B-21 and the ECM connector B-10.
1. Disconnect the intermediate connector B-21 and the ECM connector B-10.
2. Measure the resistance between the intermediate connector B-21 (terminal No. 7) and the ECM connector B-10 (terminal No. 2).
- Should be less than 2 ohms.
3. Measure the continuity between the intermediate connector B-21 (terminal No. 7) and ground.
- Not continuity
Q: Is the harness wire in good condition?
YES : Go to Step 8.
NO : Repair it. Refer to General (Electrical), Harness Connector Inspection. Then go to Step 9.
STEP 8. Using the oscilloscope, check the No. 1 cylinder injector.
1. Disconnect the intermediate connector B-21 and connect the test harness MB991658 between the separated connectors.
2. Connect the oscilloscope probe to injector intermediate connector terminal to No. 7.
NOTE: When measuring with the ECM side connector, disconnect all ECM connectors. Connect the check harness special tool (MB992110) between the separated connectors. Then connect an oscilloscope probe to the check harness connector terminal No. 2.
3. Start the engine and run at idle.
4. Measure the waveform.
- The waveform should show a normal pattern similar to the illustration.
5. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the waveform normal?
YES : It can be assumed that this malfunction is intermittent. Refer to General (Body and Chassis), How to Use Troubleshooting/Inspection Service Points-How to Cope with Intermittent Malfunctions.
NO : Replace the ECM. When the ECM is replaced, register the ID code. Refer to Diagnosis-ID Codes Registration Judgment Table [Vehicles with KOS] or Diagnosis-ID Codes Registration Judgment Table [Vehicles with WCM]. Then go to Step 9.
STEP 9. Test the OBD-II drive cycle.
1. Carry out a test drive with the drive cycle pattern. Refer to MFI Diagnostic Function-OBD-II Drive Cycle-Pattern 24. OBD-II Drive Cycle
2. Check the diagnostic trouble code (DTC).
Q: Is DTC P0201 set?
YES : Retry the troubleshooting.
NO : The inspection is complete.