Diagnostic Trouble Codes

Getting codes from ECU.

  1. Turn ignition switch to ON position.
  2. Use a screwdriver to turn ECM diagnostic mode selector on ECU fully clockwise.
  3. Wait for inspection lights to flash 3 times sequentially. (Mode 3/Self Diagnostic)
  4. As soon as inspection light flashes Mode 3, turn mode selector off. (fully counterclockwise)
  5. Count number of flashes and record them. Red first for Tens digit and Green for ones digit.

For example a faulty Mass Airflow Meter is code 12 or Red 1 flash and Green 2 flashes

DTC Codes

Code Definition Location
11 Crank Angle Sensor Optical Sensor in base of distributor
12 Mass Airflow Meter Large sensor in intake piping
13 Cylinder Head Temperature Sensor Front of driver side cylinder head behind timing cover
14 Car/Vehicle Speed Sensor On transmission
21 Ignition Signal Ignition coil, Power Transistor, or Crank Angle Sensor
22 Fuel Pump Control Fuel pump - tank / Fuel pump relay - passenger side behind rear interior panel
23 Throttle Position Sensor Side of throttle body on driver side
24 Neutral Safety Switch On transmission
31 AC/Load Driver Side of intake plenum
32 Start Signal No signal from key switch to ecu
34 Knock Sensor Right side of block
41 Fuel Temperature Sensor Side of fuel pressure regulator
44 Normal Operation no codes

Clearing Codes

Codes can be cleared by disconnecting the battery or removing power from ECU.
After the engine has been started 50 times any codes will be deleted.

repairs/codes.txt · Last modified: 2014/09/08 18:05 (external edit)
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