The Check Engine Light comes on after about 5 minutes when I first turn on my car. The car still runs so could it possibly be just an O2 sensor gone bad or anything emission related? If so I can just get it fixed by Honda. I know I can get the number from the green box under the glove compartment, but I haven't done it yet. Also anyone have a list of the problems and the numbers related to it that would turn on the CEL? Thanks

 

there are lots o things that can cause the computer to throw a CEL.

on stock cars, i'd put my money on it being emissions related.

 

On the passenger side of your car, under the dash beneath the glove box, you will find a green cover above the kickpanel that houses a green connector that has two connectors.

You need turn the ignition off, and using the piece of wire or paperclip, jump the blue connector so that you connect the two wires together. Basically stick one end of the paperclip or peice of wire into one prong on the connector and stick the other end of the paperclip or wire into the other prong.

Once you have done this, turn the key to the IGN position and watch your CEL light. It will illuminate in a series of flashes.

You will notice that there will be LONG flashes and SHORT flashes. All of the ECU trouble codes are two-digits. LONG flashes determine the TENS digit by the number of times it flashes, and SHORT flashes determine the ONES digit by the number of times it flashes.

ie. LONG-LONG-LONG-SHORT-SHORT-SHORT-SHORT-PAUSE

is the trouble code: 34

3 LONG flashes followed by 4 short flashes, then a long pause. If that is the only code the ECU is throwing, then the code will simply repeat until you remove the key. If, however there are more than one ECU error code, then you will see a different series of flashes followed by the long pause. Once all the ECU codes have been displayed, they will continuously cycle until you remove the key.

ie. LONG-LONG-SHORT-PAUSE-LONG-LONG-LONG-LONG-SHORT-SHORT-SHORT-PAUSE

is the trouble code: 21 and 43.

00

ECU

Defective ECU


Primary O2 sensor

Open or short in O2 sensor circuit, defective Primary O2 sensor


Secondary O2 sensor

Open or short in O2 sensor circuit, defective Secondary O2 sensor


Manifold Absolute Pressure sensor

Open or short in MAP sensor circuit, defective MAP sesnor


Crankshaft Position sensor

Timing belt slipped, defective CP sensor


Manifold Absolute Pressure sensor

Reading too low or too high, defective MAP sensor


Engine Coolant Temp circuit

Reading too low or too high, open or short in circuit, defective ECT circuit


Throttle Position circuit

Reading too low or too high, open or short in circuit, defective TPS circuit


Top Dead Center sensor

Open or short in TDC sensor circuit, defective TDC sensor


Cylinder Position sensor

Open or short in CYP sensor circuit, defective CYP sensor


Intake Air Temperature sensor

Open or short in IAT sensor circuit, defective IAT sensor


Exhaust Gas Recirculation Valve

Open or short in EGR valve circuit, defective EGR valve


Barometric Pressure sensor circuit

Defective ECM (Barometric sensor)


Idle Control System Malfunction

Defective IAC valve, defective fast idle thermo valve, throttle body


Ignition Output Signal

Missing, defective or noisy Ignition Output Signal


Fuel Injector System

Defective or malfunctioning Fuel Injector System


Vehicle Speed sensor circuit

Open or short in VS sensor circuit, defective VS sensor


Lock-up Control Solenoid

Open or short in LCS circuit, defective LCS solenoid


Electrical Load Detector circuit

Open or short in ELD circuit, defective ELD circuit


VTEC Solenoid Valve

Open or short in VTEC solenoid valve circuit, defective VTEC solenoid valve


VTEC Oil Pressure Switch

Open or short in VTEC OPS circuit, defective VTEC pressure switch


Knock sensor circuit

Open or short in Knock sensor circuit, defective Knock sensor circuit


A/T FI Signal A high/low input

Defective AFSA line, TCM


A/T FI Signal B high/low input

Defective AFSB line, TCM


Primary Heated O2 sensor heater circuit

Open or short in Primary O2 sensor heater circuit, defective Primary O2 sensor heater circuit


Fuel Supply System

Defective or malfunctioning Fuel Supply System


System too lean/rich

Fuel supply system, Primary O2 sensor, MAP sensor, contaminated fuel, valve clearance, exhaust leakage


Lean Air Fuel sensor

Open or short in Lean Air Fuel sensor circuit, defective Lean Air Fuel sensor


Crankshaft Speed Fluctuation sensor

Open or short in CKF sensor circuit, defective CKF sensor circuit


Top Dead Center sensor #2

Open or short in TDC sensor circuit, defective TDC sensor


Primary Heated O2 sensor

Slow response, exhaust leak, defective Primary Heated O2 sensor


Secondary Heated O2 sensor

Slow response, exhaust leak, defective Secondary Heated O2 sensor


Secondary Heated O2 sensor circuit

Open or short in Secondary Heated O2 sensor circuit, defective Secondary Heated O2 sensor circuit

OBD-II ONLY (1996-Present)


Catalyst System Efficiency

System below threshold, defective catalytic converter


Automatic Transaxle

A/T transmission, A/T FI data line, TCM, ECM


Random Misfire (Cylinder 1)

Ignition system, fuel supply system, MAP sensor, IAC valve, contaminated fuel, lack of fuel, fuel injector,
fuel injector circuit, low compression, valve clearance


Random Misfire (Cylinder 2)


Random Misfire (Cylinder 3)


Random Misfire (Cylinder 4)


Random Misfire (Cylinder 5)


Random Misfire (Cylinder 6)


Exhaust Gas Re-circulation

Malfunction with EGR system, insufficient flow


Engine Coolant Temp circuit

Defective ECT sensor, defective cooling system


Evaporative Emission Control System

Fuel cap loose, poor vacuum connection, fuel tank, fuel tank pressure sensor, EVAP bypass solenoid valve,
EVAP tow-way valve, EVAP control canister vent shut valve, EVAP canister, EVAP purge control solenoid valve


Fuel Tank Pressure sensor circuit

Possible leak in the Fuel Tank Emissions System, open or short in FTP sensor circuit, defective FTP sensor circuit


Evaporative Emission Control System

Insufficient Purge Flow or Defective Emissions System

 

Just a quick note thanking MaxBoost for his great write-up on engine codes.

Hopefully this evening I'll be able to use it to find the code and see what's wrong with the civic. My wife was trying to change the oil last night, and after being unable to remove the drain plug, she parked the car back in the garage. When I went out this morning, I was greeted with a lovely CEL. Being late leaving for work already, it was time to hop in one of our less gas conscious cars to get on the road.

Sivart_R1

93 VR RX-7 R1
260 RWHP, Apexi Power-FC, 3" SS Downpipe, Apexi Dual N1 Cat-back, ~2600 # curb weight

84 RX-7 GSL-SE (wife's car)

97 Civic DX 3-door (gotta love 40 MPG)