Repair Topics / Engine Code Reader

• How to retrieve trouble codes
• Why does the engine stall after replacing the battery?
• Why is my engine running rough?
• Why is code gathering incomplete?
• Why won't my engine crank over?
• Why does my engine have low power output?
• How an idle air controller works
• How to check compression
• Why does my engine stall?
• How to test engine vacuum
• How to test fuel delivery system
• Engine cranks but wont start
• Engine cranks excessively
• Engine stalls
• Engine vibration
• Engine has excessive smoke
• Rapid ticking sounds when engine is cranked
• Engine has lean mixture codes
• Engine idles high
• Engine idles low
• Engine is making excessive noises
• How to tune up your engine
• How does a MAF mass air flow sensor work?
• How to test an oxygen sensor

MORE: Engine code scanner questions

Code Reader Information

Question:  2000 Ford Mustang, mileage: 87,000. My check engine light come on the other day, the car seemed to run fine. Should I worry about this?

Answer: The Main Engine/Transmission management system (PCM - Powertrain Control Module) is what controls your car engine, transmission and emissions systems. The PCM is a small dedicated computer loaded with a operating program. The "Service Engine Soon" is illuminated when the PCM has detected a malfunction in the monitoring system. A computer scanner can read trouble codes to inform you on the particular sensor that has failed. The 02 sensor (oxygen sensor) is a maintenance item and should be replaced every 60,000 to 90,000 miles and will cause the "service engine soon" light.

Engine Scanner: All 1995 or newer cars and light trucks are equipped with a computer controlled engine management system. Is your "check Engine" light on. You can scan your computer for fault or error codes with a hand held scanner for less than $70 at eautoelectronics.com. The information will pinpoint the malfunctioning components and the sensors that need to be replaced. Simply clear codes when complete.

After scanning your vehicle you will receive a trouble code that will indicate the sensor or system that is out of operation range. But additional tests that can effect the sensor or system that need to be considered.

Example:1 If scanning indicates a MAS (Mass Air Flow) problem. Inspect the intake boot or PCV Valve for cracks or tears. Losing vacuum between the throttle body and the mass air flow causing a false reading.

Example:2 If scanning indicates a EVAP (Evaporative Emissions) system failure. Inspect gas cap to be fastened properly. When your PCM pressure tests the fuel vapor system it can tell you there is a leak just not where, so check the obvious, check the remainder of the EVAP system from there.

Repair Topics / Engine Code Reader

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