| 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 P0016: Crankshaft Position - Camshaft Position Correlation (Bank 1 Sensor A)
- DTC P0018: Crankshaft Position - Camshaft Position Correlation (Bank 2 Sensor A)
Circuit Description
The crankshaft position sensor (NE signal) consists of a magnet, iron core and pickup coil. NE signal plate has 34 teeth and is installed near the crankshaft timing pulley. NE signal sensor generates 34 signals at every engine revolution. ECM detects crankshaft angle and engine speed based on NE signals, and cylinder detection based on combination of VV1+ and NE signals. If DTC P0016 is set, there is deviation in crankshaft position sensor signal and VVT sensor 1 signal (2 trip detection logic). If DTC P0018 is set, there is deviation in crankshaft position sensor signal and VVT sensor 2 signal (2 trip detection logic). Check mechanical system (jumping teeth of timing belt) or ECM.
Diagnostic Aids
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.