DTC P1530: Ignition Timing Adjustment Switch CKT Malfunction

Ensure test switch terminal of test connector (located next to PCM) is not grounded by a jumper wire. Remove jumper wire if necessary. Turn ignition on. Using a voltmeter, measure voltage between ground and terminal "E" of test connector. See Figure . If voltage is 10-14 volts, check for an intermittent problem. See TESTS W/O CODES article. If voltage is not as specified, check Purple/Green wire for short to ground. Repair as necessary. If wire is okay, replace PCM. Retest system.