U3777 Oldsmobile Starfire Diagnostic Trouble Code

U3777 Oldsmobile Starfire code definition:
U3777 is a kind of OBD-II Diagnostic U-Network Diagnostic Trouble Code for Oldsmobile Starfire.

U3777 Oldsmobile Starfire is described as Oxygen Sensor Circuit No Activity Detected Bank 2 Sensor 1. This code appears when the PCM (powertrain control module, also known as ECM or engine control module in other brands) remains at or close the 0.450 set voltage point. Other symptoms that may indicate this problem are when the Check Engine Light illuminates and when there is a visible lack of engine power.

Symptoms

Symptoms of a U3777 Oldsmobile Starfire diagnostic trouble code may include:
Place of U3777 in engine

Possible Causes :

  • Rough running engine due to misfiring plugs. Many engines have misfire codes to indicate the cylinder effected, such as P0307 for number 7.
  • Rarely - faulty Powertrain Control Module (PCM-programming required after replacement)
  • Low fuel pressure caused by a clogged filter, failing fuel pump, failed fuel pressure regulator or clogged or leaking injectors.

Common Misdiagnoses

  1. Vehicle Speed Output Circuit Problem
  2. Cruise Control Servo Indicates Low Problem
  3. A/C System High Pressure High Temperature Problem
  4. PCM Stack Overrun Problem
  5. Transmission Control Module Reprogrammable Memory Problem

Repair Processes :

Look for missing ground strap or a rusty ground where the fuel tank is grounded to the frame. Check for damage to the wiring harness connector. 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.

Process Tips

Diagnostic trouble code U3777 Oldsmobile Starfire 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 U3777 Oldsmobile Starfire.

Fortunately, U3777 Oldsmobile Starfire is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

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