Honda Civic ECU Codes
If your check engine light is on:
1. Remove the kick panel on the passenger side
2. Locate the plug with the (usually) green boot on it.
3. Remove the boot so you can access the plug.
4. Jump the 2 wires together with a wire or even a paperclip.
5. Turn the car to the on position but do not start the car.
6. Now look at the CEL on the dash.
1 long flash = 10, 1 short flash = 1. So 2 long flashes and 3 short flashes = 23. Which is a knock sensor code. If there is more than one code there will be a pause between them. You know your at the end of the codes when they start repeating.
1 - Oxygen Sensor "A" (Primary)
2 - Oxygen Sensor "B" (Secondary)
3 - MAP Sensor (Manifold Absolute Pressure)
4 - CKP Sensor (Crankshaft Position Sensor)
5 - MAP Sensor (Manifold Absolute Pressure) Mechanical Problem
6 - ECT Sensor (Engine Coolant Temperature)
7 - TP Sensor (Throttle Position)
8 - TDC Sensor (Top Dead Center)
9 - CYP Sensor (Cylinder) Not a valid code for TB Injected Hondas.
10 - IAT Sensor (Intake Air Temperature)
12 - EGR Lift Sensor (Exhaust Gas Recirculation)
13 - BARO Sensor (Atmospheric Pressure)
14 - IAC Valve (Idle Air Control)
15 - Ignition Output Signal
16 - Fuel Injector System
17 - VSS (Vehicle Speed Sensor)
19 - Automatic Transmission Lock Up Control Solenoid Valve
20 - Electrical Load Detector
21 - VTEC Solenoid Valve
22 - VTEC Oil Pressure Switch
23 - KS (Knock Sensor)
30 - Automatic Transmission Signal: "A" / SEAF / SEFA / TMA or TMB
31 - Automatic Transmission Signal "B"
41 - Primary Oxygen Sensor - Heater
43 - Fuel Supply System
45 - System Too Lean or Too Rich (obd2 +)
48 - LAF Sensor (Lean Air Fuel)
54 - CKF Sensor (Crankshaft Speed Fluctuation)
58 - TDC Sensor 2 (Top Dead Center)
61 - Oxygen Sensor, Heated - Sensor 1 (Primary)
63 - Oxygen Sensor, Heated - Sensor 2 (Secondary)
65 - Oxygen Sensor Heater (Secondary)
67 - Catalyst system Efficiency Below Threshold
70 - Automatic Transmission Malfunction
71 - Cylinder 1 Misfire or a Random Misfire
72 - Cylinder 2 Misfire or a Random Misfire
73 - Cylinder 3 Misfire or a Random Misfire
74 - Cylinder 4 Misfire or a Random Misfire
75 - Cylinder 5 Misfire or a Random Misfire
76 - Cylinder 6 Misfire or a Random Misfire
80 - Exhaust Gas Recirculation Insufficient Flow
86 - ECT Sensor (Engine Coolant Temperature)
90 - Evaporative Emission Control System
91 - Fuel Tank Pressure Sensor Low Input Signal
92 - Evaporative Emission Control System