1991 Honda Accord OBD Plug Location & Trouble Codes

Since your Honda Accord is pre-OBD-II it does not have an OBD-II Data Link Connector which would normally used on a 1996 and newer Honda Accord; to pull trouble codes with a scan tool. On older model Accords, you can retrieve trouble codes by inserting a jumper wire at the diagnostic connector located in the passenger side kick panel. The connector may be blue or yellow in color. If the connector has not been used before, you may find it still taped or strapped to the main wiring harness going to the ECU (engine control unit). Insert the jumper wire in the 2 PIN service connector between pins 1 and 2. You should also see a 3 PIN connector. This is used for a trouble code scanner. Trouble codes will be stored in the ECU even if the check engine light is not on.

Once the jumper is inserted, turn on the ignition key. The trouble code(s) will begin flashing using the check engine light indicator. Begin counting the flashes. Use Trouble Code 23 as a guide. Example: 2 long flashes followed by 3 short flashes = Trouble Code 23. If more than one trouble code exists there will be a long pause in between the codes.

Honda Accord OBD-I Trouble 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