P0204
DTC P0204: Injector Circuit Malfunction - Cylinder 4Injector Circuit - Cylinder 2,4,6 Part 1:
Injector Circuit - Cylinder 2,4,6 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 grounded by the ECM
- 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
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:)
- Injector failed.
- Open or shorted injector circuit harness damage, 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
STEP 1. Using scan tool MB991958, check actuator test item 02, 04, 06: 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 02, 04, 06 Injectors.
4. Warm up the engine to normal operating temperature: 80 °C to 96 °C (176°F to 205 °F).
- Does the idle state worsen when the injector is cut off. (Does idling become unstable or does the engine stall)
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 the connector at injector for damage.
a. Check the connector B-02 when checking No. 2 cylinder.
b. Check the connector B-06 when checking No. 4 cylinder.
c. Check the connector B-25 when checking No. 6 cylinder.
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 10.
STEP 3. Check the injector.
1. Disconnect the injector connector B-02
2. Measure the resistance between injector side connector terminal No. 1 and No. 2.
Standard value: 13 - 16 Ohms [at 20 °C (68 °F)]
Q: Is the resistance between 13 and 16 Ohms ?
YES: Go to Step 4.
NO: Replace the injector. Then go to Step 10.
STEP 4. Check the power supply voltage at injector connector.
1. Disconnect connector B-02
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 A-18X 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 A-18X (terminal No. 4) and injector connector B-02 (terminal No. 1) when checking No. 2 cylinder.
b. Repair harness wire between MFI relay connector A-18X (terminal No. 4) and injector connector B-06 (terminal No. 1) when checking No. 4 cylinder.
c. Repair harness wire between MFI relay connector A-18X (terminal No. 4) and injector connector B-25 (terminal No. 1) when checking No. 6 cylinder.
Then go to Step 10.
NO: Repair or replace it. Refer to Harness Connector Inspection. 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 A-18X (terminal No. 4) and injector connector B-02 (terminal No. 1) when checking No. 2 cylinder.
b. Check the harness wire between MFI relay connector A-18X (terminal No. 4) and injector connector B-06 (terminal No. 1) when checking No. 4 cylinder.
c. Check the harness wire between MFI relay connector A-18X (terminal No. 4) and injector connector B-25 (terminal No. 1) when checking No. 6 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 connector C-51 at ECM
Q: Is the connector in good condition?
YES: Go to Step 8.
NO: Repair or replace it. Refer to Harness Connector Inspection. 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-02 (terminal No. 2) and ECM connector C-51 (terminal No. 9)
b. Check the harness wire between injector connector B-06 (terminal No. 2) and ECM connector C-51 (terminal No. 2)
c. Check the harness wire between injector connector B-25 (terminal No. 2) and ECM connector C-51 (terminal No. 25)
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-02
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. 9 when checking No. 2 cylinder.
- ECM or PCM terminal No. 2 when checking No. 4 cylinder.
- ECM or PCM terminal No. 25 when checking No. 6 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. Refer to How to Use Troubleshooting/ Inspection Service Points.
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 - Procedure 6 - Other Monitor. OBD-II Drive Cycle Pattern Lists
2. Check the diagnostic trouble code (DTC).
Q: Are DTC P0202, P0204 and P0206 sets?
YES: Retry the troubleshooting.
NO: The inspection is complete.