Symptoms
Symptoms of a P2192 engine code may include:
- Malfunction Indicator Light (MIL) illuminated
- Lack of power
- Occasional misfires
- Poor fuel economy
Causes
Possible causes for this code definition include:
- Faulty Air/Fuel Ratio Sensor or Oxygen Sensor (AFR/O2)
- Faulty Mass Air Flow (MAF) Sensor
- Rarely – Faulty Powertrain Control Module (PCM)
Diagnostic and Repair Procedures
A good starting point is always to check the Technical Service Bulletins (TSBs) for your specific vehicle. Your issue might be a known problem with a published fix from the manufacturer, which can save you time and money during diagnosis.
First, note if there are any other diagnostic trouble codes. If any are related to the fuel system, diagnose those first. Misdiagnosis is known to occur if this code is diagnosed before related fuel system codes have been thoroughly diagnosed and dismissed.
Once located, visually inspect the connectors and wiring. Look for chafing, rubbing, bare wires, burns, or melted plastic. Disconnect the connectors and carefully inspect the terminals (the metal parts) inside. Check if they appear corroded, burnt, or possibly greenish compared to the normal metallic color you’re used to seeing. You can get electrical contact cleaner at any auto parts store if terminal cleaning is needed. If not available, use 91% isopropyl alcohol and a soft plastic-bristled brush to clean them. Then let them air dry, get some dielectric silicone compound (the same type used for bulb sockets and spark plug wires), and apply it where the terminals make contact.
If you have a scan tool, clear the diagnostic codes from memory and see if this code returns. If it doesn’t, the connections were likely your problem.
If the code returns, we’ll need to test the voltage signal from the MAF sensor to the PCM. Monitor the MAF sensor voltage on your scan tool. If a scan tool isn’t available, test the signal from the MAF sensor with a Digital Volt-Ohm Meter (DVOM). With the sensor connected, attach the red voltmeter lead to the MAF sensor signal wire and the black voltmeter lead to ground. Start the engine and monitor the MAF sensor input. As engine RPM increases, the MAF sensor signal should increase. Check the manufacturer’s specifications, as there may be a chart indicating the voltage at a given RPM. If it fails this test, replace the MAF sensor and retest.
If the previous tests passed and the code is still present, monitor the Air/Fuel Ratio Sensor or Oxygen Sensor (AFR/O2). If it continuously indicates the engine is running rich, locate all possibilities that could cause a rich running condition. These include:
- Fuel system, including fuel pressure regulator/fuel pressure
- Fuel pressure sensor
- Fuel injectors
- Post-catalytic converter oxygen sensor
- EVAP system, including the purge control valve
- If the AFR/O2 sensor indicates the engine is running normally or even rich, a PCM may be suspected only after all other issues have been ruled out.
Again, it cannot be overemphasized that all other codes must be diagnosed before this one, as issues causing other codes to set may also cause this one.