Neutral Safety Switches

► What is a Neutral Safety Switch?

► Symptoms of a Failed Neutral Safety Switch

► DIY Procedures to Replace a Neutral Safety Switch

► Neutral Safety Switch Replacement Cost

What is a Neutral Safety Switch?

 

A neutral safety switch (also called inhibitor switch) is a safety device used in automobiles that are equipped with an automatic transmission.   The purpose of the neutral safety switch is to prevent the engine from cranking (and possibly starting) when the transmission is in gear.  In other words, a properly functioning neutral safety switch will only allow the engine to crank and start if the shifter lever is in the Park or Neutral position.

A faulty neutral safety switch may allow the engine to crank over and even start when the transmission is in gear.  Such occurrences could result in serious personal injury or death.  Therefore, it is highly recommended that you replace a faulty neutral safety switch immediately.

Symptoms of a Failed Neutral Safety Switch:

►  Engine does not crank over when shifter is in the Park position.  Assuming you have a fully charged battery, clean battery cables, a working starter motor and the transmission shifter lever is in the Park or Neutral position, the cause of a no crank condition may be a faulty neutral safety switch.

►  When the shifter is placed in Neutral, the engine cranks and starts normally. If the engine does not crank when the transmission is in Park but does crank when the shifter is in Neutral, the neutral safety is bad or the shifter cable (if equipped) is damaged, loose or misadjusted.

►  Engine cranks when the shifter lever is in any gear, including Drive and Reverse (1999 and older vehicles). If the engine cranks when the transmission is in gear – the neutral safety switch is not working and must be replaced.

►  Reverse lights (or back-up lights as they are also called) not working in conjunction with anyone of the above symptoms. In many vehicles, the neutral safety switch is responsible for turning on the back-up lights when the transmission is in Reverse. If you are experiencing a no crank condition combined with your reverse lights not working the neutral safety switch is bad.

Do-it-Yourself Procedures for Replacing a Neutral Safety Switch

 

Time and Cost

Approximate time to complete: 1-hour Cost for Neutral Safety Switch: Low $25   High $160 Note: The cost for a neutral safety switch is normally between $30 and $60.  For certain imports and other high-end late model vehicles the cost can be significantly higher.

Things You Will Need:

►  Replacement Neutral Safety Switch

►  10 MM Wrench or 10 MM socket with ratchet

►  12 MM Wrench or 12 MM socket with ratchet

►  Pliers

►  Flat Head Screwdriver

Floor Jack and Jack Stands or Car Ramps

1) Park vehicle on hard level surface.  Set the emergency brake and place shifter lever in the “P” Park position.  Pull hood latch.

2) Raise front of vehicle.  Use car ramps or floor jack to raise front of vehicle.  If floor jack is used, the raised vehicle must be secured with jack stands.  DO NOT WORK UNDERNEATH A RAISED VEHICLE SECURED BY A JACK ONLY.  If your vehicle is front wheel drive, you should be able to replace the switch from the top.  Raising the vehicle will not be necessary.

IMPORTANT: With the full weight of the vehicle resting on the jack stands, push against the front corner of the vehicle to test stability.  If the vehicle moves, reset the jack stands.  Or, for this particular job, driving the front wheels on car ramps is recommended.

3) Open the hood and disconnect the negative battery cable.  Be sure to position the battery cable end away from the battery terminal so there is no chance of arching.

4) From underneath a rear wheel drive vehicle or from under the hood on a front wheel drive vehicle, locate the neutral safety switch.  Some vehicles have a plastic cover covering the switch. The neutral safety switch is mounted to the transmission (or transaxle) by two or three 10mm or 12mm bolts. The shifter cable/linkage is attached to the switch and it has a single electrical connector plugged into it.

5) Unplug the electrical connector from the switch.  Electrical connectors are plastic and can become brittle over time, so be careful not to break the connector when unplugging it from the switch.

6) Remove the shifter linkage from the Pin extruding from the transmission and through the neutral safety switch.  The linkage is typically held on with a 12mm nut or bolt.

7) Loosen and remove the two 10 MM bolts holding the switch to the transmission.  Remove the neutral safety switch. IMPORTANT: Make note of the slot of the old neutral safety switch before remove it so you can install the new switch the same way.

8) Install the new Neutral Safety Switch is reverse order.

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