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View Full Version : 93 civic dx check engine light stuck on


legendary20x
Feb 13, 2010, 11:20 AM
Check engine light stuck on and I don't get any codes at all I've done the paper clip but nothing comes on in the dash if you could help please

TxGreaseMonkey
Feb 13, 2010, 12:22 PM
When you turn the ignition switch to ON (Position II), does the Check Engine Light (CEL) come on and then go off after 2 seconds? If not, the problem is with the ACG (ALT) (S) fuse, in the under dash fuse/relay box; ECM (perform the K-Test, below); main relay; or the ignition switch. Perform tests in that order.

The ECM has likely failed. Here's how to test it:

The K-Test: Remove the MAP Sensor connector and turn the ignition switch to ON (Position II). Using a multimeter, check for 5 volts going between the MAP Sensor connector's reference wire (+) and ground. As you look at the connector, this is the socket on the right. Really press the black test lead into a cleaned main ECM ground on the thermostat housing. If the voltage is low, it's probably indicating ECM failure. Most failed ECMs will record a fraction of a volt. To me, the K-Test is simple, elegant, and accurate.

Here's how to replace the ECM yourself:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-selected-other-vehicles-46563-3.html#post235038

If I'm right, you just saved yourself $1,400.