U2181 Toyota Corolla code definition:
U2181 is a kind of OBD-II Diagnostic U-Network Diagnostic Trouble Code for Toyota Corolla.
U2181 Toyota Corolla 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 of a U2181 Toyota Corolla 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
Possible Causes :
Rarely - faulty Powertrain Control Module (PCM-programming required after replacement)
Rough running engine due to misfiring plugs. Many engines have misfire codes to indicate the cylinder effected, such as P0307 for number 7.
A large vacuum leak would cause a massive amount of un-metered air to enter the intake manifold resulting in an overly lean mixture.
Crankshaft Position Sensor Circuit Performance Problem
TP Sensor Learn Not Complete Problem
Low Coolant Circuit Problem
Cruise Control System - Vehicle Accel Too High Problem
Kick-Down Switch Failed Short 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.
It should be pretty close to battery voltage (12 volts). If not, then this is the circuit that has the problem.
Diagnostic trouble code U2181 Toyota Corolla 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 U2181 Toyota Corolla.
Fortunately, U2181 Toyota Corolla is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.
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