| CAUTION | If ECM replacement is instructed in following testing, always ensure ECM harness connector and ground circuit are okay. If either are suspect, repair and repeat testing to confirm ECM malfunction. If ECM is replaced, ECM must be programmed with proper ignition key code for engine immobilizer system. For programming procedures, see COMPUTER RELEARN PROCEDURES - LEXUS article in GENERAL INFORMATION. |
Code Definition
- DTC P0345: Camshaft Position Sensor "A" Circuit (Bank 2)
- DTC P0347: Camshaft Position Sensor "A" Circuit Low Input (Bank 2)
- DTC P0348: Camshaft Position Sensor "A" Circuit High Input (Bank 2)
Circuit Description
VVT sensor LH (camshaft position sensor No. 1 (Bank 2)) consists of a magnet and IC circuit board in which MR device is built. On signal plate for VVT signal, there are 3 convex sides on its outer circumference. When camshaft turns, air-gap between protrusion on signal plate and sensor will change, and magnetic field applied to MR device in sensor will change. A signal is output based on change in resistance of MR device caused by these changes. In addition, VVT sensor LH adopts a sensor using a signal plate and a magnetic resistance element. By switching air-gap of signal plate and sensor, ECM voltage will be converted to a rectangular waveform or pattern and output as a signal.
If DTCs are set, there has been no VVT sensor (camshaft position sensor No. 1 (Bank 2)) signal to ECM for 5 seconds or more. Possible causes are
- Open or short in VVT sensor.
- Faulty VVT sensor.
- Faulty camshaft timing gear.
- Faulty ECM.
Diagnostic Aids
- If DTCs P0345, P0347 or P0348 are displayed, check left bank VVT sensor (camshaft position sensor No. 1).
- Read freeze frame data using hand-held tester or OBD-II scan tool, as freeze frame data records engine conditions when a malfunction is detected. When troubleshooting, it is useful to determine whether vehicle was running or stopped, engine was warmed up or not, air-fuel ratio was lean or rich, etc. at time of malfunction.