P0348
1UR-FE ENGINE CONTROL: SFI SYSTEM: P0340,P0342,P0343,P0345,P0347,P0348: Camshaft Position Sensor Circuit Malfunction
DESCRIPTION
The intake camshaft VVT sensor (VV1 and VV2 signal) consists of a magnet and MRE (Magneto resistance Element).
The intake camshaft has 3 teeth on its outer circumference. When the intake camshaft rotates, changes occur in the air gaps between the 3 teeth and MRE, which affects the magnetic field. As a result, the resistance of the MRE fluctuates. The VVT sensor converts the camshaft rotation data into pulse signals, uses the pulse signals to determine the camshaft angle, and sends the data to the ECM.
The crankshaft angle sensor rotor has 34 teeth. The MRE generates 34 signals for each crankshaft revolution. Based on a combination of the VVT signal and NE signal, the ECM detects the crankshaft angle. Then the ECM uses this data to control fuel injection time and injection timing. Also, based on the NE signal, the ECM detects the engine speed.
- Reference: Inspection using an oscilloscope
Standard:
HINT
VV1 and VV2 are the VVT sensor signals, and NE is the crankshaft position sensor signal.
MONITOR DESCRIPTION
If no signal is transmitted by the VVT sensor despite the engine running, or the rotations of the camshaft and crankshaft are not synchronized, the ECM interprets this as a malfunction of the sensor.
Also, when the sensor output voltage remains at below 0.3 V, or higher than 4.7 V for more than 4 seconds, the ECM stores a DTC.
MONITOR STRATEGY
TYPICAL ENABLING CONDITIONS
P0340, P0345
P0342, P0343, P0347, P0348
TYPICAL MALFUNCTION THRESHOLDS
P0340
P0342
P0343
P0345
P0347
P0348
COMPONENT OPERATING RANGE
CONFIRMATION DRIVING PATTERN
- Connect the Techstream to the DLC3.
- Turn the engine switch on (IG) and turn the Techstream on.
- Clear DTCs (even if no DTCs are stored, perform the clear DTC operation).
- Turn the engine switch off and wait for at least 30 seconds.
- Turn the engine switch on (IG) and turn the Techstream on.
- Start the engine.
- Idle the engine for 10 seconds or more [A].
- Enter the following menus: Powertrain / Engine and ECT / Trouble Codes [B].
- Read the pending DTCs.
HINT
- If a pending DTC is output, the system is malfunctioning.
- If a pending DTC is not output, perform the following procedure.
- Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
- Input the DTC: P0340, P0342, P0343, P0345, P0347 or P0348.
- Check the DTC judgment result.
HINT
- If the judgment result shows NORMAL, the system is normal.
- If the judgment result shows ABNORMAL, the system has a malfunction.
- If the judgment result shows INCOMPLETE or UNKNOWN, perform steps [A] through [B] again.
- If no pending DTC is output, perform a universal trip and check for permanent DTCs DTC Check / Clear.
HINT
- If a permanent DTC is output, the system is malfunctioning.
- If no permanent DTC is output, the system is normal.
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT
- Read freeze frame data using the Techstream. Freeze frame data records the engine conditions when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air-fuel ratio was lean or rich, and other data from the time the malfunction occurred.
- Bank 1 refers to the bank that includes the No. 1 cylinder*.
- *: The No. 1 cylinder is the cylinder which is farthest from the transmission.
- Bank 2 refers to the bank that does not include the No. 1 cylinder.
PROCEDURE
1. CHECK HARNESS AND CONNECTOR (SENSOR POWER SOURCE)
(a) Disconnect the VVT sensor connector.
(b) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
Text in Illustration
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
2. CHECK HARNESS AND CONNECTOR (VVT SENSOR FOR INTAKE CAMSHAFT - ECM)
(a) Disconnect the VVT sensor connector.
(b) Disconnect the ECM connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
3. CHECK SENSOR INSTALLATION (VVT SENSOR FOR INTAKE CAMSHAFT)
(a) Check the VVT sensor installation.
OK:
Sensor is installed correctly.
NG -- SECURELY REINSTALL SENSOR Installation
OK -- Continue to next step.
4. INSPECT INTAKE CAMSHAFT (TEETH)
(a) Check the teeth of the camshaft.
OK:
Teeth do not have any cracks or deformation.
NG -- REPLACE INTAKE CAMSHAFT Removal
OK -- Continue to next step.
5. REPLACE VVT SENSOR
(a) Replace the VVT sensor Removal.
NEXT -- Continue to next step.
6. CHECK WHETHER DTC OUTPUT RECURS
(a) Connect the Techstream to the DLC3.
(b) Turn the engine switch on (IG).
(c) Turn the Techstream on.
(d) Clear DTCs.
(e) Start the engine and idle it for 10 seconds or more.
(f) Enter the following menus: Powertrain / Engine and ECT / Trouble Codes / Pending.
(g) Read DTCs.
Result
HINT
If the engine does not start, replace the ECM.
B -- REPLACE ECM Removal
A -- END