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Can No One Help Me With A Brake Light Problem?


rob24chevy's Avatar
Member

Join Date: Jan 2005
Posts: 80

01-15-05, 05:42 PM   #1  
Can No One Help Me With A Brake Light Problem?

91 S10 Blazer 4.3 NON-ABS and the brake light started blinking one day with my wife as she was going down the road. 1 steady then 9 quick blinks. It did that for a while but now it just stays on. Fluid is full , new pads , checked the rear shoes they look fine not really sure what is going on. Pedal feels good and it is not the parking brake . Would someone give me some kind of place to look plzzzzzz. thanx. I asked about this a couple days ago but got no reply, does no one know or just dont see my posts? plzzz let me know something plzz

 
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jeff67's Avatar
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Join Date: Dec 2001
Posts: 616
NC

01-15-05, 08:16 PM   #2  
You might have rear Abs. This might help: http://www.talkaboutautos.com/group/...ges/59413.html

 
Stevo2's Avatar
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Join Date: Sep 2002
Posts: 431

01-16-05, 12:39 AM   #3  
You may have just rear wheel anti-lock brakes? A code 9 would indicate a speed sensor failure if so.

Description and Operation

Brake Light Circuit

The vehicle instrument cluster has a red "Brake" warning light to alert the driver to the following conditions:

1.Parking brake applied
2.A hydraulic failure in either the front or rear channel
3.An anti-lock light circuit problem exists

An ignition switch-controlled circuit provides power to the "Brake" light in the vehicle instrument cluster. There are three parallel paths to chassis ground to complete the circuit:

Through the parking brake switch contacts
Through the combination valve differential pressure switch contacts
Through the ECU circuitry
The ECU completes the "Brake" light circuit for several reasons:


1.To conduct a "Brake" light circuit check at the beginning of each ignition cycle
2.To alert the driver of a 4WAL malfunction related to the foundation brakes
3.The ECU also monitors the "Brake" light circuit. An isolation diode (Dl) allows an ECU monitor circuit to be grounded by the differential pressure switch, which also provides a complete circuit for the "Brake" light. As a diagnostic action to this condition, the ECU will adjust its antilock control programming.

The operation of the park brake switch does not affect the ECU monitor circuit for the "Brake" light, due to the blocking action of D1. Another isolation diode (D2) prevents the park brake switch from providing an input to the daytime running lights module (used in Canadian vehicles).

The ECU checks the "Brake" light circuit at the beginning of each ignition cycle. If the ECU monitors low voltage at terminal H before it attempts to ground the light circuit, it determines that a short exists.

 
rob24chevy's Avatar
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Join Date: Jan 2005
Posts: 80

01-18-05, 04:09 PM   #4  
Thanx guys it does have rear ABS, i looked harder and it does. So i guess ill pick-up a speed sensor. Thanx a million for all you guys time.

 
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