P0201
DTC P0201: Injector Circuit - Cylinder 1, DTC P0202: Injector Circuit - Cylinder 2, DTC P0203: Injector Circuit - Cylinder 3, DTC P0204: Injector Circuit - Cylinder 4Injector Circuit Part 1:
Injector Circuit Part 2:
CIRCUIT OPERATION
- The injector power is supplied from the MFI relay (terminal No. 4).
- The ECM
TECHNICAL DESCRIPTION
- The amount of fuel injected by the injector is controlled by the amount of continuity time the coil is
- A surge voltage is generated when the injectors are driven and the current flowing to the injector coil is shut off.
- The ECM
DESCRIPTIONS OF MONITOR METHODS
- If a surge current is not generated in the coil after the injector has been actuated, an open or short circuit is determined to have occurred.
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
Logic Flow Chart:
Logic Flow Chart
Check Condition
- Engine is running.
Judgment Criterion
- 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 - Pattern 21 OBD-II Drive Cycle Pattern Lists.
TROUBLESHOOTING HINTS (The most likely causes for this code to be set are:)
- Injector failed.
- Open or shorted injector circuit, or connector damage.
- ECM failed.
- PCM failed.
DIAGNOSIS
Required Special Tools:
- MB991958: Scan Tool (MUT-III Sub Assembly)
- MB991824: V.C.I.
- MB991827: USB Cable
- MB991911: Main Harness B
- MB991348: Test Harness Set
STEP 1. Using scan tool MB991958, check actuator test item 01, 02, 03, 04: Injectors.
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, 02, 03, 04 Injectors.
4. Warm up the engine to normal operating temperature: 80 degrees C to 95 degrees C (176 degrees F to 203 degrees F).
- Does the idle state worsen when the injector is cut off.
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.
NO: Go to Step 2.
STEP 2. Check the connector at injector for damage.
a. Check connector B-22 at No. 1 cylinder.
b. Check connector B-20 at No. 2 cylinder.
c. Check connector B-18 at No. 3 cylinder.
d. Check connector B-17 at No. 4 cylinder.
Q: Is the connector in good condition?
YES: Go to Step 3.
NO: Repair or replace it. Then go to Step 10.
STEP 3. Check the injector.
1. Disconnect the injector connector B-22
2. Measure the resistance between injector side connector terminal No. 1 and No. 2.
Standard value: 10.5 - 13.5 Ohms [at 20 degrees C (68 degrees F)]
Q: Is the resistance between 10.5 and 13.5 Ohms [at 20 degrees C (68 degrees F)]?
YES: Go to Step 4.
NO: Replace the injector. Then go to Step 10.
STEP 4. Measure the power supply voltage at injector connector.
1. Disconnect connector B-22
2. Turn the ignition switch to the "ON" position.
3. Measure the voltage between terminal No. 1 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 6.
NO: Go to Step 5.
STEP 5. Check connector B-12X at MFI relay for damage.
Q: Is the connector in good condition?
YES: Repair harness wire between MFI relay connector and injector connector because of open circuit or short circuit to ground.
a. Repair harness wire between MFI relay connector B-12X (terminal No. 4) and injector connector B-22 (terminal No. 1) at No. 1 cylinder.
b. Repair harness wire between MFI relay connector B-12X (terminal No. 4) and injector connector B-20 (terminal No. 1) at No. 2 cylinder.
c. Repair harness wire between MFI relay connector B-12X (terminal No. 4) and injector connector B-18 (terminal No. 1) at No. 3 cylinder.
d. Repair harness wire between MFI relay connector B-12X (terminal No. 4) and injector connector B-17 (terminal No. 1) at No. 4 cylinder.
Then go to Step 10.
NO: Repair or replace it. Then go to Step 10.
STEP 6. Check for harness damage between MFI relay connector and injector connector.
a. Check the harness wire between MFI relay connector B-12X (terminal No. 4) and injector connector B-22 (terminal No. 1) at No. 1 cylinder.
b. Check the harness wire between MFI relay connector B-12X (terminal No. 4) and injector connector B-20 (terminal No. 1) at No. 2 cylinder.
c. Check the harness wire between MFI relay connector B-12X (terminal No. 4) and injector connector B-18 (terminal No. 1) at No. 3 cylinder.
d. Check the harness wire between MFI relay connector B-12X (terminal No. 4) and injector connector B-17 (terminal No. 1) at No. 4 cylinder.
Q: Is the harness wire in good condition?
YES: Go to Step 7.
NO: Repair it. Then go to Step 10.
STEP 7. Check harness connector C-119 at ECM
Q: Is the harness connector in good condition?
YES: Go to Step 8.
NO: Repair or replace it. Then go to Step 10.
STEP 8. Check for open circuit and short circuit to ground and harness damage between injector connector and ECM connector
a. Check the harness wire between injector connector B-22 (terminal No. 2) and ECM connector C-119
b. Check the harness wire between injector connector B-20 (terminal No. 2) and ECM connector C-119
c. Check the harness wire between injector connector B-18 (terminal No. 2) and ECM connector C-119
d. Check the harness wire between injector connector B-17 (terminal No. 2) and ECM connector C-119
Q: Is the harness wire in good condition?
YES: Go to Step 9.
NO: Repair it. Then go to Step 10.
STEP 9. Using the oscilloscope, check the injector.
1. Disconnect the injector connector B-22
2. Connect the oscilloscope probe to the injector side connector terminal No. 2.
NOTE: When measuring with the ECM or PCM side connector, connect an oscilloscope probe to the each of the following terminals.
- ECM or PCM terminal No. 1 at No. 1 cylinder.
- ECM or PCM terminal No. 9 at No. 2 cylinder.
- ECM or PCM terminal No. 24 at No. 3 cylinder.
- ECM or PCM terminal No. 2 at No. 4 cylinder.
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.
NO: Replace the ECM or PCM. Then go to Step 10.
STEP 10. 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 - Pattern 21 OBD-II Drive Cycle Pattern Lists.
2. Check the diagnostic trouble code (DTC).
Q: Are DTC P0201, P0202, P0203 and P0204 set?
YES: Retry the troubleshooting.
NO: The inspection is complete.