U0291 Porsche 937 Diagnostic Trouble Code

U0291 Porsche 937 code definition:
U0291 is a kind of OBD-II Diagnostic U-Network Diagnostic Trouble Code for Porsche 937.

U0291 Porsche 937 is described as Intake Air Temperature (IAT) Circuit Malfunction. It's actually a general trouble code for a problem on IAT electrical circuit sensor, as it sends incorrect voltage input signals to the PCM. If the car doesn't start, they will proceed by testing the voltage at the fuel pump connector and see if the fuel pump relay, fuse, and PCM circuitry should be inspected.

Symptoms

Symptoms of a U0291 Porsche 937 diagnostic trouble code may include:
Place of U0291 in engine

Possible Causes :

  • Faulty IMRC actuator relay (if equipped)
  • A large air leak at or near the number one oxygen sensor would also cause a lean mixture.
  • Dirty air cleaner element Damaged DPF

Common Misdiagnoses

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

Repair Processes :

Pack the connector cavity with dielectric silicone compound (same stuff they use for light bulb sockets and spark plug wires) and reassemble. 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. Replace the oxygen sensor that is downstream from the catalytic converter on the side of the engine that does not contain cylinder #1. Also, if a oxygen sensor code stating "heater circuit malfunction" the sensor has most probably failed.

Process Tips

Diagnostic trouble code U0291 Porsche 937 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 U0291 Porsche 937.

Fortunately, U0291 Porsche 937 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

Diagnostic Trouble Code look-up and check engine light code viewer.

About Us | Contact | Privacy

Copyright 2024 - https://DiagnosticTrouble.com

Small Logo