CEL

Check Engine Light

This indicator (usually on the dash) comes on to indicate that the ECU thinks something is wrong. The ECU will usually indicate an error code by flashing the CEL in some manner.

• On OBD0 cars, there is a window on the ECU through which a blinking LED can be seen to read codes.

• On OBD1 cars, there is a connector located under the dash by the passenger footwell that must be shorted. This will cause the dash CEL to blink, indicating which codes are being thrown.

• On OBD2 cars, there is a connector located under the dash by the passenger footwell that must be shorted. This will cause the dash CEL to blink, indicating which codes are being thrown. You can also use an OBD2 scan tool which connects to the plug by the driver's side footwell. It is a gray connector that should be easily identifiable.

Solid Check Engine Light

If the CEL is lit solid and does not blink (after jumping the service check connector on OBD1 ) and the car runs poorly the following could be the problem:

• A faulty ECU (means any other component failure other than listed here)
• Poor soldering connections
• Check Sum error
• Faulty program stored in the ROM
• Faulty ROM chip
• Faulty 74HC373 chip

See Troubleshooting Solid CEL

"Phantom" Check Engine Light

Sometimes you may get a CEL that doesn't show up when you turn the car off. In order to check these, you must do the following:

• DON'T turn the ignition off
• Jump the service check connector just like normal

Now the CEL will turn off briefly and then start flashing the codes like normal.

See Honda Error Codes