Trouble Code Definition

1991 Honda Accord DX, 2D Coupe, StandardSECTION Trouble Code Definition
TROUBLE CODE IDENTIFICATION CHART

Code (1) System Affected Probable Cause
0 (2) ECU No signal to ECU
1  O2 Sensor Problem in O2 sensor circuit
3  MAP Sensor Electrical problem in MAP sensor
4  Crank Angle Sensor (CRANK) Open or shorted signal circuit
5  MAP Sensor Mechanical problem in MAP sensor
6  Coolant Temperature (TW) Sensor Open or shorted signal circuit
7  Throttle Angle Sensor Open or shorted signal circuit
8  Crank Angle Sensor (TDC) Open or shorted signal circuit
9  Crank Angle Sensor (CYL) Open or shorted signal circuit
10  Intake Air Temperature Problem with sensor
12  EGR System No EGR action
13  Atmospheric Pressure (PA) Problem with PA circuit
14  Electronic Air Control Valve (EACV) Open or shorted signal circuit
15  Ignition Output Signal Electrical problem in signal circuit
16  Fuel Injector Problem in fuel injector circuit
17  Vehicle Speed Sensor (VSS) Open or shorted signal circuit
20  Electrical Load Detector Problem with electrical load detector circuit
30  A/T FI Signal A Problem in A/T control unit and ECU circuit
31  A/T FI Signal B Problem in A/T control unit and ECU circuit
41  O2 Sensor Heater Problem with O2 sensor circuit
43  Fuel Supply System Problem with O2 sensor circuit or fuel system
(1) If codes other than these are indicated, repeat self-diagnosis. If code(s) reappear, substitute a known good ECU, and recheck codes. If code(s) clear, replace ECU.
(2) NO CHECK ENGINE LIGHT  or CHECK ENGINE LIGHT ON, WON'T FLASH CODE  .
RENDER: 1.0x

NO RELATED

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • You smell fuel, burning insulation, or see smoke.
  • Brakes feel soft, pull hard to one side, or make grinding noises.
  • The engine overheats, stalls repeatedly, or misfires under load.
  • You are missing required tools, torque specs, or safe lifting equipment.
  • You are not confident in the next step or safety outcome.