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Home >> Lexus >> 2012 >> IS 250C V6-2.5L (4GR-FSE) >> Repair and Diagnosis >> A L L Diagnostic Trouble Codes ( DTC ) >> Testing and Inspection >> P Code Charts >> P0348

P0348





4GR-FSE ENGINE CONTROL: SFI SYSTEM: P0340, P0342, P0343, P0345, P0347, P0348: Camshaft Position Sensor Circuit Malfunction


DESCRIPTION

The VVT sensor (for intake camshaft) (VV1, VV2 signal) consists of a magnet and MRE (Magneto Resistance Element).

The camshaft timing gear assembly has a sensor plate for the VVT sensor. When the intake camshaft rotates, changes occur in the air gaps between the timing rotor and MRE, which affects the magnetic field. As a result, the resistance of the MRE material fluctuates. The VVT sensor converts the intake camshaft rotation data to pulse signals, uses the pulse signals to determine the camshaft angle, and sends it to the ECM.

Then the ECM uses this data to control fuel injection duration, fuel injection timing and Variable Valve Timing (VVT) system.





- Reference: Inspection using an oscilloscope





HINT
- The correct waveform is as shown.
- VV1+ and VV2+ stand for the VVT sensor for intake camshaft signal, and NE+ stands for the crankshaft position sensor signal.





MONITOR DESCRIPTION

If no signal is transmitted by the VVT sensor despite the engine revolving, or the rotations of the camshaft and the crankshaft are not synchronized, the ECM interprets this as a malfunction of the sensor.

MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS

All





P0340 (Case 1)





P0340 (Case 2)





P0342 and P0343





P0345





P0347 and P0348





TYPICAL MALFUNCTION THRESHOLDS

P0340 (Case 1) and P0345





P0340 (Case 2)





P0342 and P0347





P0343 and P0348





COMPONENT OPERATING RANGE





CONFIRMATION DRIVING PATTERN

1. Connect the Techstream to the DLC3.

2. Turn the engine switch on (IG) and turn the Techstream on.

3. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure) Reading and Clearing Diagnostic Trouble Codes.

4. Turn the engine switch off and wait for at least 30 seconds.

5. Turn the engine switch on (IG) and turn the Techstream on [A].

6. Start the engine.

7. Idle the engine for 10 seconds or more [B].

8. Enter the following menus: Powertrain / Engine / Trouble Codes [C].

9. Read Pending DTCs.

HINT
- If a pending DTC is output, the system is malfunctioning.
- If a pending DTC is not output, perform the following procedure.

10. Enter the following menus: Powertrain / Engine / Utility / All Readiness.

11. Input the DTC: P0340, P0342, P0343, P0345, P0347 or P0348.

12. 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 N/A, perform steps [A] and [B] again.

13. If no pending DTC is output, perform a universal trip and check for permanent DTCs Reading and Clearing Diagnostic Trouble Codes.

HINT
- If a permanent DTC is output, the system is malfunctioning.
- If no permanent DTC is output, the system is normal.

WIRING DIAGRAM

Refer to DTC P0335 P0335.

INSPECTION PROCEDURE

HINT
- Read freeze frame data using the Techstream. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. 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.
- If no problem is found by this diagnostic troubleshooting procedure, troubleshoot the engine mechanical system.
- 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 VVT SENSOR FOR INTAKE CAMSHAFT (SENSOR POWER SOURCE)

(a) Disconnect the VVT sensor for intake camshaft connector.

(b) Turn the engine switch on (IG).

(c) Measure the voltage according to the value(s) in the table below.





Standard Voltage:





Text in Illustration





(d) Reconnect the VVT sensor for intake camshaft connector.

NG -- CHECK WHETHER DTC OUTPUT RECURS (DTC P0340, P0342, P0343, P0345, P0347 OR P0348)
OK -- Continue to next step.

2. CHECK HARNESS AND CONNECTOR (VVT SENSOR FOR INTAKE CAMSHAFT - ECM)

(a) Disconnect the VVT sensor for intake camshaft connector.

(b) Disconnect the ECM connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance (Check for Open):





Standard Resistance (Check for Short):





(d) Reconnect the VVT sensor for intake camshaft connector.

(e) Reconnect the ECM connector.

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 for intake camshaft installation.





OK:

Sensor is installed correctly.

NG -- SECURELY REINSTALL VVT SENSOR FOR INTAKE CAMSHAFT Installation
OK -- Continue to next step.

4. CHECK CAMSHAFT TIMING GEAR ASSEMBLY (TEETH OF PLATE)

(a) Check the teeth of the signal plate.

OK:

Sensor plate teeth do not have any cracks or deformation.

NG -- REPLACE CAMSHAFT TIMING GEAR ASSEMBLY Removal
OK -- Continue to next step.

5. CHECK VALVE TIMING (CHECK FOR LOOSE TIMING CHAIN AND JUMPED TEETH) P0011

NG -- ADJUST VALVE TIMING Reassembly
OK -- Continue to next step.

6. REPLACE VVT SENSOR FOR INTAKE CAMSHAFT

(a) Replace the VVT sensor for intake camshaft Removal.

NEXT -- Continue to next step.

7. CHECK WHETHER DTC OUTPUT RECURS (DTC P0340, P0342, P0343, P0345, P0347 OR P0348)

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(c) Turn the Techstream on.

(d) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.

(e) Turn the engine switch off and wait for at least 30 seconds.

(f) Start the engine.

(g) Turn the Techstream on.

(h) Drive the vehicle in accordance with the driving pattern described in the Confirmation Driving Pattern.

(i) Enter the following menus: Powertrain / Engine / Trouble Codes / Pending.

(j) Read the DTCs.

Result:





HINT
If the engine does not start, replace the ECM.

B -- REPLACE ECM Removal

A -- END

8. CHECK HARNESS AND CONNECTOR (VVT SENSOR FOR INTAKE AND EXHAUST CAMSHAFT - ECM)

(a) Disconnect the VVT sensor for intake camshaft connector.

(b) Disconnect the ECM connectors.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance (Check for Open):





(d) Disconnect the VVT sensor for exhaust camshaft connector.

(e) Measure the resistance according to the value(s) in the table below.

Standard Resistance (Check for Short):





(f) Reconnect the VVT sensor for intake or exhaust camshaft connector.

(g) Reconnect the ECM connectors.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE ECM Removal
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