Honda OBD1 Trouble Codes and Fault Code List >> Honda 84-85 Accord & 87 Civic

General Information

  • Trouble codes are displayed by four LED’s in engine control module (ECM) 1
  • LED’s are numbered 8-4-2-1, left to right

Accessing Trouble Codes

  • Access engine control module (ECM):
  • Civic 2
  • Accord 3
  • Switch ignition ON
  • Check MIL illuminates
  • Check LED’s in ECM are flashing
  • Count LED flashes and compare with trouble code table below
  • If malfunction indicator lamp (MIL) is ON constantly and no trouble codes are displayed (LED not flashing), this indicates an engine control module (ECM) fault
  • Switch ignition OFF

Clearing Trouble Codes

  • After the faults have been rectified, erase the trouble codes as follows:
  • Civic – Remove fuse No. 10 (10A) from LH fascia fusebox for 10 seconds minimum
  • Accord – Disconnect battery ground cable for 10 seconds minimum
  • Reinstall fuse
  • Repeat accessing procedure to ensure no data remains in ECM fault memory

 Trouble Codes

84-85 Accord 1.8L Engine Code: ES3
87 Civic 1.5L Engine Code: D15A3
Trouble codeFault locationProbable Cause
0000MIL only illuminated -ECM or ECM wiring faultWiring, ECM
0001Oxygen sensor (02S)Spark plug misfire, wiring, 02S, ECM
0020Engine control module (ECM)ECM
0021Manifold absolute pressure (MAP) sen sorWiring, MAP sensor, ECM
0400Engine control module (ECM)-ECM
0401Manifold absolute pressure (MAP) sensor vacuum hoseHose leak
0420Engine coolant temperature (ECT) sen sorWiring, ECT sensor, ECM
0421Throttle position (TP) sensorWiring, TP sensor, ECM
8000Engine speed (RPM)/crankshaft position (CKP) sensorsWiring, RPM/CKP sensor, ECM
8001Engine speed (RPM)/camshaft position (CMP) sensorsRPMICMP sensor, ECM
8020lntake air temperature (lAT) sensorWiring, IAT sensor, ECM
8021CO adjustment resistorWiring, CO adjustment resistor, ECM
8400Engine control module -CivicECM
8400Exhaust gas recirculation (EGR) control system -AccordHose leak/blockage, wiring, EGR valve/position sensor, EGR solenoid, ECM
8401Barometric pressure sensor (BARO)Wiring, BARO sensor, ECM
8420Engine control module (ECM)ECM
8421Engine control module (ECM)ECM