Note On Intermittents

If PCM Code E24 is stored as a history code, select parameter P.0.9. Lift drive wheels, place transmission in Drive and let vehicle idle in low gear. Manipulate related wiring while observing engine data parameter P.0.9. If failure is induced, vehicle speed reading will drop from its normal value to reading of zero MPH. Check for open or short on circuits No. 400 and 401. Check terminal contact at speed sensor and PCM. If wiring and connectors are okay, substitute a known good sensor, and repeat test.

Fig 1: PCM Code E24 Schematic - Vehicle Speed Sensor Ckt. Problem

Courtesy of GENERAL MOTORS CORP.

Fig 2: PCM Code E24 Flow Chart - Vehicle Speed Sensor Ckt. Problem

Courtesy of GENERAL MOTORS CORP.