1G 1g Code Reader - CEL CODE READER

This is a How-To on figuring out your Check engine light(CEL) for 1g.


Tools:
Volt Meter or LED

Connection:
Connect the positive of the volt meter or LED to pin #1 and the ground to #12 pin on the port. SEE PIC.

After you got that done, turn your key to the ON position and watch the pulse.

A long pulse counts as 10, a short pulse as 1.


1 long pulse: Engine Control Unit ( ECU )

pulses 1 by 1: Normal operation


Codes/pulses:

11. Oxygen Sensor

12. Air Flow Sensor

13. Intake Air Temperature Sensor

14. Throttle Position Sensor

15. Motor Position Sensor

21. Engine Coolant Temperature Sensor

22. Crank Angle Sensor

23. No 1 Top dead center sensor

24. Vehicle Speed Sensor (Reed Switch)

25. Barometric Pressure Sensor

31. Detonation Sensor

36. Ignition Timing Adjustment Signal

41. Fuel Injector

42. Fuel Pump

43. EGR (California) ((This is also a common code when the ecu capacitors have to be replaced.))

44. Ignition Coil ((This is also a common code when the ecu capacitors have to be replaced.))


If you have any questions, Please PM me.

 

[steve]

If you use a LED you need a 12v one or a regular LED and a current limiting resistor (For a typical red LED with a 2v forward voltage drop, at 680 ohm 1/4 watt resistor should work).

Pin 1 on the DLC is going to be the positive and pin 12 the ground.

I like using a Radio Shack 12v Piezo Buzzer for the same reason you used the overrange on the DMM, it's easier to count the sound.

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