P0204

DTC P0204: Injector Circuit-Cylinder 4

CAUTION:
If DTC P0204 has been set, TCL related DTC U1120 is also set. After P0204 has been diagnosed, don't forget to erase DTC U1120.


















CIRCUIT OPERATION

- The injector power is supplied from the MFI relay (terminal No. 4).
- The ECM [M/T] or the PCM [A/T] controls the injector by turning the power transistor in the ECM [M/T] or the PCM [A/T] "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 [M/T] or the PCM [A/T].

DESCRIPTIONS OF MONITOR METHODS

The ECM [M/T] or the PCM [A/T] 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.

DTC SET CONDITIONS[ Circuit continuity - shorted high]

Logic Flow Chart





Check Condition

- Engine is running.
Judgement Criterion

- The coil current is 4.5 ampere or more with the injector driving.

OBD-II DRIVE CYCLE PATTERN

Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 23 Monitors, Trips, Drive Cycles and Readiness Codes .

TROUBLESHOOTING HINTS (The most likely causes for this code to be set are:)

- No. 4 cylinder injector failed.
- Open or shorted No. 4 cylinder injector circuit, harness damage or connector damage.
- ECM failed. [M/T]
- PCM failed. [A/T]

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
- MB991923: Power Plant ECU Check Harness

STEP 1. Using scan tool MB991958, check actuator test item 4: No. 4 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 4 No. 4 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. How to Cope With Intermittent Malfunctions.

NO Go to Step 2.

STEP 2. Check harness connector B-26 at No. 4 cylinder injector for damage.





Q. Is the harness connector in good condition?

YES Go to Step 3.

NO Repair or replace it. Harness Connector Inspection.
Then go to Step 10.

STEP 3. Check the No. 4 cylinder injector.





(1)Disconnect the No. 4 cylinder injector connector B-26.





(2)Measure the resistance between injector side connector terminal No. 1 and No. 2.
Standard value: 10.5 - 13.5ohms [at 20°C (68°F)]

Q. Is the measured resistance between 10.5 and 13.5 ohms [at 20°C (68°F)]?

YES Go to Step 4.

NO Replace the No. 4 cylinder injector. Then go to Step 10.

STEP 4. Measure the power supply voltage at No. 4 cylinder injector connector.





(1)Disconnect connector B-26 and measure at the harness side.
(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 harness connector B-16X at MFI relay for damage.





Q. Is the harness connector in good condition?

YES
Repair harness wire between MFI relay connector B-16X (terminal No. 4) and No. 4 cylinder injector connector B-26 (terminal No. 1). Then go to Step 10.

NO Repair or replace it. Harness Connector Inspection.
Then go to Step 10.

STEP 6. Check for harness damage between MFI relay connector B-16X
(terminal No. 4) and No. 4 cylinder injector connector B-26 (terminal No. 1).









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 B-22 at ECM [M/T] or PCM [A/T] for damage.





Q. Is the harness connector in good condition?

YES Go to Step 8.

NO Repair or replace it. Harness Connector Inspection.
Then go to Step 10.

STEP 8. Check for open circuit and short circuit to ground and harness damage between No. 4 cylinder injector connector B-26 (terminal No. 2) and ECM [M/T] or PCM [A/T] connector B-22 (terminal No. 139).









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 No. 4 cylinder injector.





(1)Disconnect the No. 4 cylinder injector connector B-26 and connect the test harness special tool MB991658 between the separated connectors. (All terminals should be connected.)





(2)Connect the oscilloscope probe to the injector side connector terminal No. 2.
NOTE:
When measuring with the ECM [M/T] or the PCM [A/T] side connector, disconnect all ECM [M/T] connectors or PCM [A/T] connectors. Connect the check harness special tool (MB991923) between the separated connectors. Then connect the oscilloscope probe to the check harness connector terminal No. 139.

(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. How to Cope With Intermittent Malfunctions.

NO Replace the ECM or the PCM. When the ECM or the PCM is replaced, register the encrypted code. Immobilizer System.
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 23 Monitors, Trips, Drive Cycles and Readiness Codes.

(2)Check the diagnostic trouble code (DTC).

Q. Is DTC P0204 set?

YES Retry the troubleshooting.
NO The inspection is complete.