P1EF0 Alta 2-litre Diagnostic Trouble Code

P1EF0 Alta 2-litre code definition:
P1EF0 is a kind of OBD-II Diagnostic P-Powertrain Diagnostic Trouble Code for Alta 2-litre.

P1EF0 Alta 2-litre 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. The PCM then uses this data to provide the right strategies for the fuel delivery and ignition timing of the engine.

Symptoms

Symptoms of a P1EF0 Alta 2-litre diagnostic trouble code may include:

Faulty or damaged wiring
The engine oil will exhibit dilution from the ECUs attempts to increase engine temperature. Some vehicles advance the fuel injection timing slightly after top center to afterburn a small amount of fuel to increase exhaust temperatures. Some of this fuel enters the crankcase. When the ECU determines the necessity to regenerate the DPF, the service life of the oil be shortened significantly
Poor fuel economy
Hesitation upon acceleration

Possible Causes :

Some aftermarket accessories and performance modifications
A faulty oxygen sensor. This will set a code in itself, however, a faulty oxygen sensor does not automatically condemn the sensor. The code just means that the sensor signal was not within specifications. An air leak or any of the above will cause an erroneous signal. There is a multitude of O2 codes relating to O2 performance which gives a clue to the problematic area.
A large vacuum leak would cause a massive amount of un-metered air to enter the intake manifold resulting in an overly lean mixture.

Common Misdiagnoses

TP Sensor Learn Not Complete Problem
Low Coolant Circuit Problem
Cruise Control System - Vehicle Accel Too High Problem
TFP Valve Position Switch-Drive Without Drive Ratio Problem
Problem

Repair Processes :

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. Look for rubbing, scraping, bare wires, worn spots or melted plastic connectors. Pull the connectors apart and carefully look at the terminals (the metal parts) inside the connectors.

Process Tips

Diagnostic trouble code P1EF0 Alta 2-litre 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 P1EF0 Alta 2-litre.

Fortunately, P1EF0 Alta 2-litre is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.