Using Voltmeter
Before entering on-board diagnostics, see SERVICE PRECAUTIONS . Turn ignition switch to OFF position. Locate Data Link Connector (DLC), next to fuse block. Connect volt-meter positive lead to DLC self-diagnostic test mode terminal and negative lead to either DLC ground terminal. See Fig. 1 .
Turn ignition switch to ON position. Disclosure of ECM memory will begin. If 2 or more systems are non-functional, they are indicated by order of increasing code number. Indication is made by 12-volt pulses of voltmeter pointer. A constant repetition of short 12-volt pulses indicates system is normal. If system is abnormal, voltmeter will pulse between zero and 12 volts.
Signals will appear on voltmeter as long and short 12-volt pulses. Long pulses represent tens; short pulses represent ones. For example, 4 long pulses and 3 short pulses indicate Code 43. After recording trouble code(s), perform necessary repair(s) to indicated circuit(s). See TROUBLE CODES .
Aug 21, 2010 at 6:22 PM
