C3142 Lexus Is Diagnostic Trouble Code

C3142 Lexus Is code definition:
C3142 is a kind of OBD-II Diagnostic C-Chassis Diagnostic Trouble Code for Lexus Is.

C3142 Lexus Is is defined as Camshaft Position Sensor A Circuit Low. This means the CMP (camshaft position) sensor circuit on engine bank 1 sends an irregular reading. Other serious codes may cause this code to pop up, and they may come with dangerous drivability issues that may expose you to safety risks and cause damage to the engine in the long run.

Symptoms

Symptoms of a C3142 Lexus Is diagnostic trouble code may include:

Fuel pressure too low
Rich or lean exhaust
Diminished fuel efficiency
The light may stay on or light intermittently as the DPF regenerates. The engine will be sluggish on acceleration.

Possible Causes :

An air leak forward of the DPF will change the sensor readings resulting in the code
Rusty exhaust systems, cracked exhaust manifolds or damaged or missing gaskets or donuts will cause air leaks.
Faulty IMRC actuator/sensor

Common Misdiagnoses

Exhaust Gas Recirculation System Valve 1 Problem
BBV Sensor Circuit Low Voltage Problem
Transmission Engaged At High Throttle Angle Problem
Cruise Inhibit Control Circuit Problem
TFP Valve Position Switch-Drive Without Drive Ratio Problem

Repair Processes :

If all testing has passed so far yet you still have the same code, check your scan tool and see if it can open and close the IMRC valve. With the valve disconnected, the red voltmeter lead should be attached to the IMRC valve power wire and the black voltmeter lead connected to ground.

Process Tips

Diagnostic trouble code C3142 Lexus Is is not difficult to diagnose and repair. Thus, it always pays to have a qualified technician to look after your vehicle should this error code arise.

Diagnosing this code requires the engine to be in good running shape, without unmetered air entering the engine. If other codes that relates to misfiring condition, lean running or air entering the engine is present, then you must first fix those error codes before C3142 Lexus Is.

Fortunately, C3142 Lexus Is is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.