I have 2001 outback with automatic transmission.The car will only start you push the interlock switch thought the center console little hole and move the shifter to neutral postion.Checked all the fuses and they were good.Took console apart and checked the park switch.It seems good. you can hear the relay under the dash clicking when you move the shifter on and off the switch.Only thing I could find was the interlock solenoid is no activating no matter what you do.I tried a test light on the wires to it but no matter what position you have shifter with ignition on and foot on brake there was no power to it.

The transmission is locked into park by a solenoid activated little pin that stops the shifter from moving. It is attached to the shifter area under the console. You say you replaced the brake light switch, but did you check the brake lights to see if they work?

Automatic Transmission Shift Lock Control Description
The brake transmission shift interlock (BTSI) system prevents the automatic transmission from being shifted out of PARK unless the brake pedal is depressed. When the brake pedal is depressed, the BTSI solenoid releases a lock pawl. This enables the shift linkage to move and the shift lever to operate.
When service operations are required, the BTSI system can be overridden.
On vehicles equipped with a column-mounted shift lever, override the BTSI system by performing the following steps:

1. Turn the ignition switch to the OFF position.
2. Remove battery voltage from the solenoid.
3. Turn the ignition switch to the ON position.

For vehicles equipped with floor-mounted shift levers, an override lever is mounted on the right side of the assembly. The override lever can be accessed by removing the shift lever boot. Push the lever to the left in order to override the BTSI.
Which does your S-10 have column or floor shift ? No relay ,has a solenoid .
With Column Shift A/T
The brake transmission shift interlock (BTSI) system prevents the automatic transmission from being shifted out of the PARK position unless the following conditions are present:
?€¢
The brake pedal is depressed.

?€¢
The ignition switch is turned to the RUN or the START position.

When the ignition switch is in the RUN or the START position, the current flows from the B/U Lamp fuse located in the underhood bussed electrical center (UBEC) through CKT 839 (PNK) to the park/neutral position switch. The park/neutral position switch also feeds the backup lamps portion of the switch. With the transmission in the PARK position, the current flows to the BTSI fuse located in the underhood bussed electrical center (UBEC) through CKT 275 (LT GRN). The current then flows to the TCC/stoplamp switch through CKT 584 (LT GRN/BLK). The current continues to the BTSI solenoid through CKT 1135 (DK GRN/WHT). The ground path is provided through CKT 1850 (BLK) to G207. When the brake pedal is depressed, the normally closed contacts in the TCC/stoplamp switch open and the current flow is interrupted. When the current flow is interrupted, the BTSI solenoid de-energizes. The transmission may then shift to another gear. When the transmission shifts to another gear (except PARK), the contacts in the park/neutral position switch open. This condition stops the current flow to energize the solenoid when the brake pedal releases.

Whic

When you changed the ****** fluid was it brown? If so I regret to inform you, you may need a new transmission. The brown color is due to the clutches in the trans, wearing down over time. Does it shift hard when you drive it? If it does that is another sign the trans has gone out the window.

Start with the safety interlock. If you have an automatic transmission, put your foot on the brake and shift thru the gears while holding the key to start. If the engine cranks, adjust or replace the safety interlock switch.
If you have a standard transmission, remove the cable from the switch above the clutch pedal and connect the terminals in the connector with a paper clip, then push in clutch and try to start. If that works, replace the switch.

If the problem is not the interlock, please see my tip at http://www.fixya.com/cars/r6222268-engine_doesnt_crank_turn_over . These are generic instructions. If you get stuck or need specific instructions for your car, please get back to me with model, year and engine info.

Check to make sure the steering wheel is not over-cranked when you stopped the engine.

If this is not the problem, check to make sure the dowel pin securing the ignition interlock on the gear-shift has not moved or fallen out. The can be found under the cowl for the center console on an automatic transmission model.

Good luck!

CHECK BRAKE LIGHT SWITCH FUSE AND BRAKE TRANSMISSION SHIFT INTERLOCK SOLENOID FUSE.IF BOTH FUSES ARE GOOD.PROBLEM IS THE BRAKE SWITCH FAULTY OR BRAKE TRANSMISSION SHIFT INTERLOCK SOLENOID IS FAULTY.

SOUNDS LIKE SHIFT INTERLOCK SOLENOID IS STUCK. TRY GIVING A FEW HITS AND PUSH ON AND OFF ON BRAKE PEDAL AND SEE IF YOU CAN FREE IT UP. JAR IT AROUND A BIT LIKE TRYING TO WIGGLE IT OUT WHICLE PUSHING ON AND OFF ON BRAKE PEDAL SEVERL TIMES. DO YOU HEAR A CLICK IN CENTER CONSOLE WHEN PUSHING BRAKE?

The easiest way is to carefully connect jumpleads and start the car or remove the battery and charge it,as the car is probably an automatic i would`nt tow it even fora short distance.

Hello Joe...The Aveo has had it shares of problems, and this is one of them....NHTSA issued several bulletins on the 04 Aveo...this following is the one pertaining to the shift interlock.....

Make : CHEVROLET Model : AVEO Year : 2004
Manufacturer : GENERAL MOTORS CORP.
Service Bulletin Num : 070730007 Date of Bulletin: APR 01, 2007
NHTSA Item Number: 10022265
Component: POWER TRAIN:AUTOMATIC TRANSMISSION
Summary:
AUTOMATIC TRANSAXLE/TRANSMISSION SHIFT LEVER MAY NOT SHIFT OUT OF PARK (REPLACE BRAKE TRANSAXLE SHIFT INTERLOCK (BTSI) SOLENOID). *KB

Take that bulletin number to your dealer and see if they can help.

Untill you can get it repaired heres a little tip for getting it out of park....There is a a little hole in front of their gearshift lever that can correct the problem, temporarily. It should say "brake interlock release" or something like that. With car running, put a key-size object into it and push down while moving the lever. It does not damage the transmission, it just releases the lock. (make sure your foot is on the brake)

Now for the brake light issue...do you have power at the switch you replaced? If so go to the relay and check there...if no power there it's probably a bad ground.

Also...you may or may not know, but the timing belts on these Aveos are prone to failure at aprox 50k ...these failures have caused severe engine damage.
Good luck...i hope the information i've provided you find useful.
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