P0201
DTC P0201: Injector Circuit Malfunction - Cylinder 1Injector Circuit - Cylinder 1 Part 1:
Injector Circuit - Cylinder 1 Part 2:
CAUTION: If DTC P0201. has been set, TCL related DTC U1120 is also set After P0201 has been diagnosed, don't forget to erase DTC U1120 Injector Circuit - Cylinder 1.
CIRCUIT OPERATION
- The injector power is supplied from the MFI relay (terminal No. 4).
- The PCM controls the injector by turning the power transistor in the PCM "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 PCM.
- A surge voltage is generated when the injectors are driven and the current flowing to the injector coil is shut off.
- The PCM checks this surge voltage.
DESCRIPTIONS OF MONITOR METHODS
Off-surge does not occur after injector is operated
MONITOR EXECUTION
Continuous
MONITOR EXECUTION CONDITIONS (Other monitor and Sensor)
Other Monitor (There is no temporary DTC stored in memory for the item monitored)
- Not applicable
Sensor (The sensor is determined to be normal)
- Not applicable
DTC SET CONDITIONS
Logic Flow Chart:
Logic Flow Chart
Check Conditions
- Engine is running
Judgment Criteria
- Injector coil surge voltage (battery positive voltage + 2 volts) has not been detected for 2 seconds
OBD-II DRIVE CYCLE PATTERN
Refer to Diagnostic Function - OBD-II Drive Cycle - Procedure 6 - Other Monitor. OBD-II Drive Cycle Pattern Lists
TROUBLESHOOTING HINTS (The most likely causes for this code to be set are:)
- No. 1 cylinder injector failed.
- Open or shorted No1cylinder injector circuit, harness damage, or connector damage.
- PCM failed.
DIAGNOSIS
Required Special Tools:
- MB991958: Scan Tool (MUT-III Sub Assembly)
- MB991824: V.C.I
- MB991827: USB Cable
- MB991910: Main Harness A
- MB991658: Test Harness
- MB991923: Power Plant ECU Check Harness
STEP 1. Using scan tool MB991958, check actuator test item 01: 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 01, 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 How to Use Troubleshooting/Inspection Service Points.
NO: Go to Step 2.
STEP 2. Check harness connector B-32 at intermediate connector for damage.
Q: Is the connector in good condition?
YES: Go to Step 3
NO: Repair or replace it. Refer to Harness Connector Inspection. Then go to Step 12
STEP 3. Check the No. 1 cylinder injector resistance at intermediate connector B-32.
1. Disconnect the intermediate connector B-32.
2. Measure the resistance between terminal No. 5 and No. 9.
- 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 6.
NO: Go to Step 4.
STEP 4. Check the connector B-01 at No. 1 cylinder injector for damage.
Remove the intake manifold
Q: Is the harness connector in good condition?
YES: Go to Step 5.
NO: Repair or replace it. Refer to Harness Connector Inspection. Then go to Step 12.
STEP 5. Check the No. 1 cylinder injector B-01.
1. Disconnect the No. 1 cylinder injector connector B-01.
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 resistance between 10.5 and 13.5 Ohms [at 20 °C (68 °F)]?
YES: Repair harness wire between intermediate connector B-32 (terminal No. 9) and injector connector B-01 (terminal No. 1) and harness wire between No. 1 cylinder injector connector B-01 (terminal No. 2) and intermediate connector B-32 (terminal No. 5) because of open circuit or short circuit to ground or harness damage. Then go to Step 12.
NO: Replace the No. 1 cylinder injector. Then go to Step 12.
STEP 6. Measure the power supply voltage at intermediate connector B-32.
1. Disconnect the connector B-32 and measure at the female connector side.
2. Turn the ignition switch to the "ON" position.
3. Measure the voltage between terminal No. 9 and ground.
- Voltage should be battery positive voltage.
4. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is battery positive voltage (approximately 12 volts) present?
YES: Go to Step 8.
NO: Go to Step 7.
STEP 7. Check harness connector B-17X at MFI relay for damage.
Q: Is the connector in good condition?
YES: Repair harness wire between MFI relay connector B-17X (terminal No. 4) and intermediate connector B-32 (terminal No. 9) because of open circuit or short circuit to ground. Then go to Step 12.
NO: Repair or replace it. Refer to Harness Connector Inspection. Then go to Step 12.
STEP 8. Check for harness damage between MFI relay connector B-17X (terminal No. 4) and intermediate connector B-32 (terminal No. 9).
Q: Is the harness wire in good condition?
YES: Go to Step 9.
NO: Repair it. Then go to Step 12.
STEP 9. Check harness connector B-23 at PCM for damage.
Q: Is the connector in good condition?
YES: Go to Step 10.
NO: Repair or replace it. Refer to Harness Connector Inspection. Then go to Step 12.
STEP 10. Check for open circuit and short circuit to ground and harness damage between intermediate connector B-32 (terminal No. 5) and PCM connector B-23 (terminal No. 153).
Q: Is the harness wire in good condition?
YES: Go to Step 11.
NO: Repair it. Then go to Step 12.
STEP 11. Using the oscilloscope, check the No. 1 cylinder injector.
1. Disconnect the intermediate connector B-32 and connect the test harness MB991658 between the separated connectors.
2. Connect the oscilloscope probe to injector intermediate connector terminal to No. 5.
NOTE: When measuring with the PCM side connector, disconnect the all PCM connectors and connect check harness special tool (MB991923) between the separated connectors. Then connect an oscilloscope probe to terminal No. 153.
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 How to Use Troubleshooting/Inspection Service Points.
NO: Replace the PCM. Then go to Step 12.
STEP 12. Test the OBD-II drive cycle.
1. Carry out a test drive with the drive cycle pattern. Refer to Diagnostic Function - OBD-II Drive Cycle - Procedure 6 - Other Monitor. OBD-II Drive Cycle Pattern Lists
2. Check the diagnostic trouble code (DTC)
Q: Is DTC P0201 set?
YES: Repeat the troubleshooting.
NO: The procedure is complete.