P001A
DTC P001A: Camshaft Profile Control (Engine Oil Control Valve) Circuit
CIRCUIT OPERATION
- The engine oil control valve power is supplied from the MFI relay (terminal No. 2).
- The ECM controls ground engine oil control valve by turning the power transistor in the ECM "ON" and "OFF".
TECHNICAL DESCRIPTION
- The engine oil pressure switches the cams to operate the MIVEC system in the low-speed or high-speed mode in accordance with the signals from the ECM.
DESCRIPTIONS OF MONITOR METHODS
Circuit voltage stays low when solenoid status is off.
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)
- Camshaft position sensor
- Mass airflow sensor
- Engine coolant temperature sensor
- Throttle position sensor
- Injection valve
DTC SET CONDITIONS
Logic Flow Chart
Check Conditions
- Ignition switch: "ON"
- Engine oil control valve is OFF.
- Battery positive voltage is between10 and 16.5 volts.
- 0.1 seconds has elapsed after the above mentioned conditions have been met.
Judgment Criterion
- The ECM terminal voltage of engine oil control valve circuit is less than 1.5 volts 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:)
- Connector damage.
- Harness damage.
- Engine oil control valve failed.
- 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
STEP 1. Using scan tool MB991958, check data item 98:
Oil control valve.
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)Turn the ignition switch to the "ON" position.
(3)Set scan tool MB991958 to the data reading mode for item 98, Oil control valve.
- An operation sound should be heard and vibration should be felt when the engine oil control valve is operated.
(4)Turn
the ignition switch to the "LOCK" (OFF) position.
Q. Is the engine oil control valve operating properly?
YES It can be assumed that this malfunction is intermittent. How to Cope With Intermittent Malfunctions.
NO Then go to Step 2.
STEP 2. Check harness connector B-106 engine oil control valve and harness connector B-10 at ECM 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 7.
STEP 3. Check the engine oil control valve.
(1)Disconnect the engine oil control valve connector B-106.
(2)Measure the resistance between engine oil control valve side connector terminal No. 1 and No. 2.
Standard value: 6.9 - 7.9 ohms [at 20°C (68°F)]
Q. Is the measured resistance between 6.9 and 7.9 ohms [at 20°C (68°F)]?
YES Go to Step 4.
NO Replace the engine oil control valve. Then go to Step 7.
STEP 4. Measure the power supply voltage at engine oil control valve harness side connector B-106.
(1)Disconnect the connector B-106 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 5.
NO Repair it because of open circuit or harness damage between relay box (fuse No.
22) and engine oil control valve connector B-106 (terminal No. 1). Then go to Step 7.
STEP 5. Check for open circuit and short circuit to ground and harness damage between engine oil control valve connector B-106 and ECM connector B-10.
(1)Disconnect the connector B-106 and B-10 measure at the harness side.
(2)Measure the resistance between connector B-106 (terminal No. 2) and connector B-10
(terminal No. 1).
- Should be less than 2 ohms.
(3)Check for the continuity between connector B-106 (terminal No. 2) and ground.
- Not continuity.
Q. Is the harness wire in good condition?
YES Then go to Step 6.
NO Repair it. Then go to Step 7.
STEP 6. Test the OBD-II Drive Cycle.
(1)Carry out 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 P001A set?
YES 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.
NO It can be assumed that this malfunction is intermittent. How to Cope With Intermittent Malfunctions.
STEP 7. Test the OBD-II Drive Cycle.
(1)Carry out 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 P001A set?
YES Retry the troubleshooting.
NO The inspection is complete.