Diagnostic Aids
"Scan" should indicate a vehicle speed whenever drive wheels are turning greater than 3 MPH. A faulty or misadjusted park/neutral switch can result in a false Code 24. Use "Scan" tester to check for properly adjusted Park/Neutral switch in "D", "P" and "N". For additional information and testing of park/neutral switch see ENGINE SENSORS & SWITCHES in SYS/COMP TESTS article. If Code 24 is intermittent, see INTERMITTENTS in TESTS W/O CODES article.