DTC P0500 & DTC P0501: VSS Range/Performance Problem

Test drive vehicle. Using scan tool, check vehicle speed. If correct speed is not indicated, go to next step. If correct speed is indicated, problem is intermittent. System is okay at this time. Check for poor connections or loose wires at Vehicle Speed Sensor (VSS) and PCM connectors. See appropriate wiring diagram in WIRING DIAGRAMS article. Repair as necessary.
CAUTION: On 4WD, DO NOT use engine to rotate front wheels when rear wheels are on the ground. Vehicle will lurch forward suddenly when 4WD system engages.
Turn ignition off. Block rear wheels and set parking brake. Raise and support front of vehicle. Turn ignition on. DO NOT start engine. Block right front wheel and slowly rotate left front wheel by hand. Using backprobe set, measure voltage between PCM 25-pin connector "B" terminal No. 20 (Brown/Black wire) and PCM 31-pin connector "C" terminal No. 23 (Blue/White wire). See Figure and Figure . If voltage does not pulse between zero and about 5.0 volts, or battery voltage does not exist, go to next step. If voltage pulses between zero and about 5.0 volts, or battery voltage exists, substitute a known-good PCM and recheck. See SUBSTITUTING PCM in SELF-DIAGNOSTICS - INTRODUCTION article. If symptom or indication goes away, replace original PCM.
Turn ignition off. Disconnect PCM 31-pin connector "C". Turn ignition on. DO NOT start engine. Block right front wheel and slowly rotate left front wheel by hand. Using backprobe set, measure voltage between PCM 25-pin connector "B" terminal No. 20 (Brown/Black wire) and PCM 31-pin connector "C" terminal No. 23 (Blue/White wire). See Figure and Figure . If voltage pulses between zero and about 5.0 volts, or battery voltage exists, substitute a known-good PCM and recheck. See SUBSTITUTING PCM in SELF-DIAGNOSTICS - INTRODUCTION article. If symptom or indication goes away, replace original PCM. If voltage does not pulse between zero and about 5.0 volts, or battery voltage does not exist, repair open or short in Blue/White wire between PCM 31-pin connector "C" and VSS. If wire is okay, check VSS. See SYSTEM & COMPONENT TESTING article.