Chevrolet 24221125 Switch, Parking/Neutral Position & Back Up Lamp

These models are fitted with a starter/Neutral safety switch that precludes the start of the engine when shifting is not being made with the clutch pedal pushed down for manual transmission or when the shift lever is not in Neutral or Park for the automatic transmission. Starting the car with the key where appropriate in automatic-transmission vehicles should cause the engine to crank with none, one or the other, or both of the accelerator and brake pedals pressed, yet only in Park or Neutral. With a manual transmission the shift lever should be placed at Neutral and the engine should crank only when the clutch is depressed. One must ensure that the steering column lock is such that it permits the key from assumption to the Lock position solely when the shift lever is in the park in case of the automatic transmission and the reverse position in case of manual transmission. Ignition key should be operable only when in Lock position.

First, put the shift lever in NEUTRAL and apply the parking brake before removing the Automatic Transmission Shift Position Sensor Switch. The vehicle can then be raised and stands placed securely under it. By sliding out the retainer, pulling off and releasing the connector, disconnecting it from the automatic transmission shift position sensor switch followed by removal of its retainer lock and electrical connector. Pry out the pin to release the manual lever from shift cable. After that, remove manual lever nut plus manual lever itself. Finally, there is a need to take-off mounting bolts of Automatic Transmission Shift Position Sensor Switch as well as switch itself. If fitting a new switch, align slots in switch with notch on switch body and locate it over shafts. However align flats of shift shaft with those of Automatic Transmission Shift Position Sensor Switch if reinstalling old unit. Ensure that it starts only PARK and NEUTRAL after installation by testing for engine start elsewhere in case readjustment has to be done by slightly turning mounting screws in one direction or another until starting occurs only at PARK and NEUTRAL positions whereafter tightening mounting screws firmly.

The Park/Lock system prevents the shift lever from moving out of Park without depressing the brake pedal and the ignition key from being removed unless the shift lever is in Park. To remove the actuator, park the vehicle in Neutral, set the parking brake, and disable the airbag system. Disconnect the wiring and pry off the actuator from the cable shift cam and steering column. Snap the actuator onto the cable shift cam and steering column cover and reconnect the wiring. Press the adjuster block to disengage the internal teeth and slide it away from the actuator. To install the actuator, push the tab to lock it in place and reconnect the battery. Check the operation by ensuring the lever can only move out of Park when the brake pedal is depressed and readjust if needed. Finally, reinstall the knee bolster.

The back-up light switch is located on the right side of the transmission, near the center of the transmission case. To check its functionality, turn the ignition key to the On position and move the shift lever to Reverse; the back-up lights should illuminate. If they do not, first check the back-up light fuse. If the fuse is blown, trace the back-up light circuit for a short-circuit condition. If the fuse is intact, raise the vehicle and support it securely on jackstands, then place the shifter in Reverse. While working under the vehicle, unplug the back-up light switch electrical connector and use an ohmmeter to check for continuity across the terminals of the switch; continuity should exist, and if not, the switch needs replacement. If continuity is present, check for voltage at the electrical connector; one of the two terminals should have battery voltage with the ignition key in the on position. If no voltage is present, trace the circuit between the fuse block and the electrical connector for an open circuit condition. If voltage is present, trace the back-up light circuit between the electrical connector and the back-up light bulbs for an open circuit condition, keeping in mind that both bulbs could potentially be burned out. For replacement, raise the vehicle and support it securely on jackstands if not already done, then unplug the back-up light switch electrical connector and unscrew the switch from the transmission case. Apply RTV sealant or Teflon tape to the threads of the new switch to prevent leakage, install it in the transmission case, and tighten securely before plugging in the electrical connector. Finally, lower the vehicle and check the operation of the back-up lights.

The Park/Neutral Position switch, part of the transmission range switch mounted on the side of the transmission, serves as an information sensor for the Powertrain Control Module (PCM), preventing engine start in any gear other than park or neutral and activating the back-up lights when the shift lever is in reverse. To ensure proper function, verify that the engine starts only in Park or Neutral; if it starts in other gears, readjust the switch by loosening the mounting bolts and turning it slightly until the desired operation is achieved, then tighten the bolts. For replacement, disconnect the negative battery cable, apply the parking brake, and place the shift lever in Neutral. Locate the PNP switch on the transmission, disconnect the shift cable and electrical connectors, and remove the manual lever retaining nut before carefully detaching the manual lever without moving it from the Neutral position. Remove the switch retaining bolts to detach the switch from the transmission. When installing a new switch, align the slots with the notch on the switch body, or for an old switch, align the flats of the manual shaft with those of the PNP switch. Secure the switch with mounting bolts and torque them, reinstall the manual lever and tighten the nut, then reattach the shift cable and electrical connectors, completing the installation in reverse order of removal.

First, put the shift lever in NEUTRAL and apply the parking brake before removing the Automatic Transmission Shift Position Sensor Switch. The vehicle can then be raised and stands placed securely under it. By sliding out the retainer, pulling off and releasing the connector, disconnecting it from the automatic transmission shift position sensor switch followed by removal of its retainer lock and electrical connector. Pry out the pin to release the manual lever from shift cable. After that, remove manual lever nut plus manual lever itself. Finally, there is a need to take-off mounting bolts of Automatic Transmission Shift Position Sensor Switch as well as switch itself. If fitting a new switch, align slots in switch with notch on switch body and locate it over shafts. However align flats of shift shaft with those of Automatic Transmission Shift Position Sensor Switch if reinstalling old unit. Ensure that it starts only PARK and NEUTRAL after installation by testing for engine start elsewhere in case readjustment has to be done by slightly turning mounting screws in one direction or another until starting occurs only at PARK and NEUTRAL positions whereafter tightening mounting screws firmly.

First, put the shift lever in NEUTRAL and apply the parking brake before removing the Automatic Transmission Shift Position Sensor Switch. The vehicle can then be raised and stands placed securely under it. By sliding out the retainer, pulling off and releasing the connector, disconnecting it from the automatic transmission shift position sensor switch followed by removal of its retainer lock and electrical connector. Pry out the pin to release the manual lever from shift cable. After that, remove manual lever nut plus manual lever itself. Finally, there is a need to take-off mounting bolts of Automatic Transmission Shift Position Sensor Switch as well as switch itself. If fitting a new switch, align slots in switch with notch on switch body and locate it over shafts. However align flats of shift shaft with those of Automatic Transmission Shift Position Sensor Switch if reinstalling old unit. Ensure that it starts only PARK and NEUTRAL after installation by testing for engine start elsewhere in case readjustment has to be done by slightly turning mounting screws in one direction or another until starting occurs only at PARK and NEUTRAL positions whereafter tightening mounting screws firmly.

The Park/Lock system protects the shift lever from being taken out of park unless the brake pedal is depressed and also prevents the ignition key from being removed unless it is in the parked position. This happens by activating a solenoid when starting up a car that locks the car in park. When the driver pushes on the brake pedal, this solenoid becomes inactive, permitting other gears to be engaged by moving or altering the level. In case of an electric failure there is a manual means of shifting out of park. The process entails removing the shifter trim boot and finding the override lever at the top right side of shifter bracket and pushing it forward toward vehicle front. If there is need of replacing shift lock control solenoid, one should remove steering column covers and disconnect electrical connector. Then using flat-bladed screwdriver, pry off solenoid from column; installation is as simple as removal.

Before checking the Park/Neutral switch, ensure that it prevents the engine from starting in any gear other than Park or Neutral. Additionally, on 1995 and later models, check if it activates the backup lights when in Reverse.

Disconnect the shift cable from the transmission shift lever and the Park/Neutral position switch electrical connectors.

The Park/Neutral Position switch is also known as the transmission range switch.

The Park/Lock system is a safety feature that prevents the shift lever from being moved out of Park unless the brake pedal is depressed. It also prevents the ignition key from being removed unless the shift lever is in the Park position.

Unplug the electrical connectors from the PNP switch.

The manifold absolute pressure (MAP) sensor monitors intake manifold pressure changes and varies its voltage output accordingly. To check it, you should check the reference voltage and signal voltage with the ignition on and engine off, and observe voltage changes as the engine's vacuum changes.

Before checking the Park/Neutral switch, ensure that it prevents the engine from starting in any gear other than Park or Neutral. Additionally, on 1995 and later models, check if it activates the backup lights when in Reverse.

The ignition key should come out only in the Lock position.

Finally, the knee bolster should be reinstalled.

The operation of the actuator should be checked by making sure that the lever can only be moved out of Park when the brake pedal is depressed, and readjusted if necessary.

Remove the manual lever nut and the manual lever itself.

Apply the parking brake and put the shift lever in NEUTRAL.

Verify that the engine will start only in PARK and NEUTRAL.

To remove the actuator, the vehicle should be parked with the shift lever in Neutral, the parking brake set, and the airbag system disabled.

The Park/Lock system is designed to prevent the shift lever from being moved out of Park unless the brake pedal is depressed simultaneously.

The manifold absolute pressure (MAP) sensor monitors intake manifold pressure changes and varies its voltage output accordingly. To check it, you should check the reference voltage and signal voltage with the ignition on and engine off, and observe voltage changes as the engine's vacuum changes.

If the switch does not operate correctly after adjustment, it may need to be replaced.

To remove the actuator, the vehicle should be parked with the shift lever in Neutral, the parking brake set, and the airbag system disabled.