Honda and Acura OBD1 Trouble codes. How to read check engine light codes and what they mean.
In every cars life there comes a time when the dreaded CHECK ENGINE light appears. Only to strike fear in the heart of Automobile owners all over the world. Not to fear. There are many resources you can use to check and diagnose these DTC's (Diagnostic Trouble Codes.)
For 1992-1995 (OBD1) vehicles you can check these yourself by using the method shown in the picture below.
For 1996 - Newer (OBD2) vehicles you can visit a local Auto Parts supplier such as Advance Auto Parts that offers free vehicle diagnostics. Most of these free services are restircted to OBD2 vehicles and will have an explanation as to what the code is immediately. As always it's a good idea to write these codes down and do a little search online to see what other owners have run into when receiving the same codes.
Below is a list containing The most common DTCs for Honda and Acura vehicles. There is also a Diagram showing the diagnostic port used to read them.
Shown above is the location of Honda diagnostic connector:
In obd1 Hondas and Acuras there is a diagnostic port and a 2 pin connector located under the passanger side dashboard. When checking the DTC's you will need to insert a jumper wire from one pin to the other in the two pin connector. If you don't have a piece of wire around it is also commen to see people using paperclips to "jump" the two sides of the connector.
Once you have "Jumped" the 2 pin connector you now need to insert the key and turn on the vehicle. Your check engine light will then start to flash. Every long flash is considered a 10 and short a 1 with long pauses between each code. So if you receive 2 long flashes and 5 short flashes you have a code 25. Read all the codes until they start to repeat themselves. Then refer to the Table below to get the meaning of each code.
Here are some common Honda and Acura OBD1 codes:
Code 0 and 11 Electronic Control Module (ECM)
Code1 Heated oxygen sensor A
Code 2 Oxygen content B
Code 3 and 5 Manifold Absolute Pressure
Code 4 Crank position sensor
Code 6 Engine coolant temperature
Code 7 Throttle position sensor
Code 8 Top dead center sensor
Code 9 No.1 cylinder position sensor
Code 10 Intake air temperature sensor
Code 12 Exhaust recirculation system
Code 13 Barometric pressure sensor
Code 14 Idle air control valve or bad ECM
Code 15 Ignition output signal
Code 16 Fuel Injector
Code 17 Vehicle speed sensor
Code 19 A/T lock-up control solenoid
Code 20 Electric load detector
Code 21 V-TEC control solenoid
Code 22 V-TEC pressure solenoid
Code 23 Knock sensor
Code 30 A/T FI signal A
Code 30 A/T FI signal B
Code 41 Heated oxygen sensor heater
Code 43 Fuel supply system
Code 45 Fuel supply metering
Code 48 Heated oxygen sensor
Code 61 Front heated oxygen sensor
Code 63 Rear heated oxygen sensor
Code 65 Rear heated oxygen sensor heater
Code 67 Catalytic converter system
Code 70 Automatic transaxle
Code 71 Misfire detected cylinder 1
Code 72 Misfire detected cylinder 2
Code 73 Misfire detected cylinder 3
Code 74 Misfire detected cylinder 4
Code 75 Misfire detected cylinder 5
Code 76 Misfire detected cylinder 6
Code 80 Exhaust recirculation system
Code 86 Coolant temperature
Code 92 Evaporative emission control system
These DTC codes are just a starting point when trying to diagnose a check engine light. They are no replacement for a good mechanic and automotive knowledge. But they can help to ease your mind when that dreaded light comes on again.