Reading Diagnostic Trouble Codes

Notes:
- When battery voltage is low, no detection of failure is possible. Be sure to check the battery for voltage and other conditions before starting the test.
- Diagnostic item is erased if the battery or the engine control module connector is disconnected. Do not disconnect the battery before the diagnostic result is completely read.
- Make certain that the ignition switch is at OFF when the scan tool is connected or disconnected.


Using Scan Tool (ST)
1. Read and record the on-board diagnostic output.
2. Referring to the diagnostic chart, repair the faulty part.
3. Turn the ignition switch OFF and then turn it ON.
4. Erase the diagnostic trouble code.
5. Recheck that a normal code is output.

Using Voltmeter
1. Connect an analog voltmeter between the on-board diagnostic output terminal of the data link connector and ground terminal.
2. Turn on the ignition switch.
3. Read the on-board diagnostic output pattern from the voltmeter and record it.
4. Referring to the diagnostic chart, repair the faulty part.
5. Erase the diagnostic trouble code using the following procedure.

a. Turn OFF the ignition switch.
b. Disconnect the negative battery cable from the battery terminal for 10 seconds or more and then reconnect it.
c. Turn ON the ignition switch and read the diagnostic trouble code to check that a normal code is output.