P0204
DTC P0204: Injector Circuit - Cylinder 4
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
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 Diagnostic Function - OBD-II Drive Cycle - Pattern 22 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.
- 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. 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 1, 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 the for harness connector B-116 at No. 4 cylinder injector and B-10 at the ECM for damage.
Q. Is the harness connector in good condition?
YES Go to Step 3.
NO Repair it. Harness Connector Inspection.
Then go to Step 7.
STEP 3. Measure the power supply voltage at the injector connector B-116.
(1)Disconnect the injector connector B-116 (terminal No. 1) 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 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. Harness Connector Inspection.
If intermediate connector is in good condition, repair harness wire between injector relay connector A-24X (terminal No. 3) and injector connector B-116 (terminal No. 1) because of open circuit.
Then go to Step 7.
STEP 4. Check the No. 4 cylinder injector.
(1)Disconnect the No. 4 cylinder injector connector B-116.
(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 Go to Step 5.
NO Replace the No. 4 cylinder injector. Then go to Step 7.
STEP 5. Check for harness between the injector connector B-116 and the ECM connector B-10.
(1)Disconnect the injector connector B-116 and the ECM connector B-10.
(2)Measure the resistance between injector connector B-116 (terminal No. 2) and the ECM connector B-10 (terminal No. 19).
- Should be less than 2 ohms.
(3)Measure the continuity between the injector connector B-116 (terminal No. 2) and ground.
- Not continuity.
Q. Is the connector wire in good condition?
YES Go to Step 6.
NO Repair it. Harness Connector Inspection.
Then go to Step 7.
STEP 6. Using the oscilloscope, check the No. 4 cylinder injector.
(1)Disconnect the No. 4 cylinder injector connector B-116 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 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. 19.
(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. When the ECM is replaced, register the ID code. Refer to ID registration procedure manual - ID codes registration judgement table [Vehicles with KOS] or ID registration procedure manual - ID codes registration judgement table [Vehicles with WCM]. Then go to Step 7.
STEP 7. 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 22 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.