Q: How to check and replace the Park/Neutral switch on Chevrolet Blazer,S10,GMC Jimmy and Sonoma?
A: To check the Park/Neutral switch, first, ensure that it prevents the engine from starting in any gear other than Park or Neutral. Raise the vehicle and securely place it on jack stands, then unplug the electrical connector from the Park/Neutral switch. Use an ohmmeter to check continuity across the indicated switch terminals. There should be continuity with the shift lever in Park or Neutral, and no continuity in any other position. If the switch doesn't operate as described, try adjusting it before retesting, and if it still fails, replace it. For removal, apply the parking brake, place the shift lever in Neutral, disconnect the battery cable, raise the vehicle on jack stands, remove the nut and manual lever, unplug the electrical connector from the switch, and remove the switch retaining bolts. Slide the switch off the manual shaft. Installation involves using a special adjustment tool, aligning the switch with the manual shaft flats, sliding it onto the manual shaft, and securing it with mounting bolts. Remove the adjustment tool and complete the remaining installation steps, tightening the manual lever retaining nut to the specified torque.
Q: How to check the Neutral Safety Switch on Chevrolet Blazer,S10,GMC Jimmy and Sonoma?
A: Try to start the engine in each gear. The engine should crank only in Park or Neutral. Make sure the steering column lock allows the key to go into the Lock position only when the shift lever is in Park. The ignition key should come out only in the Lock position.
Q: How to check and replace Camshaft Position Sensor,Coolant Temperature Sensor,Crankshaft Position Sensor,Intake Manifold Temperature Sensor,Knock Sensor,Oxygen Sensor,Vehicle Speed Sensor,Neutral Safety Switch,MAP Sensor and Throttle Position Sensor on Chevrolet Blazer,S10,GMC Jimmy and Sonoma?
A: Various engine sensors and components have checking procedures,the engine coolant temperature (ECT) sensor is a thermistor that changes resistance with temperature, and a failure in the circuit can cause trouble codes. The resistance should be measured when cold and warm while ensuring reference voltage from PCM is around 5.0 volts for the verification. Manifold Absolute Pressure (MAP) Sensor monitors changes in intake manifold pressure then varies its voltage output accordingly. Look at the reference voltage and signal voltage with the ignition on and engine off, and observe voltage changes as the engine's vacuum changes. Intake Air Temperature (IAT) Sensor acts as a thermistor where you can measure its resistance at different temperatures to make sure it changes as expected. Also, use a scan tool to monitor the IAT sensor for performance. The oxygen sensor in exhaust detects oxygen content which you can check its millivolt signal while warming up your engine. Check whether the oxygen sensor heater has correct voltage or not. Vehicle Speed Sensor (VSS) provides speed data to PCM which can be checked for reference voltage. Depending on the type of engine, Camshaft Sensor and Crankshaft Sensor should be checked for resistance and proper signal output. Finally, Knock Sensors detect engine knock which should be checked for reference voltage and resistance. If any component fails these checks, replacement may be necessary.