Diagnostic Trouble Codes, or DTCs, are fault codes generated in the power train control module when it receives data from any of the sensors monitoring the power train which do not correlate with the data programmed into the module at the factory. Each DTC corresponds to a troubleshooting test that must be performed to fully diagnose the malfunction. Once the computer has a stored DTC, the Check Engine light turns on to alert the driver there is a malfunction. While the codes do not pinpoint the malfunction, you need to know them in order to troubleshoot the problem.
Climb into the driver’s seat and connect the scan tool to the DTC port located under the dashboard near the steering column. The port is rectangular with a plastic cap covering it. The cap should have the letters “DTC” embossed on it. You can purchase a scan tool at any major auto parts store or from a local professional tool vendor.
Refer to the scan tool’s directions on how to perform a self-test on the system then run the self-test.
Record the codes the scan tool retrieves on a piece of paper. Do not clear the codes when prompted to do so unless you are certain you have repaired the malfunction that triggered the codes in the first place.
Refer to the list of DTCs that came with the scan tool to determine which pinpoint test to use in order to repair the malfunction.
