Brake service light

jarhead2001 · 03-21-2008, 07:04 PM

My brake service light started flashing 3short flashes and one long flash
dose anybody know what this means
thanks
justin

crabtruck · 03-21-2008, 07:30 PM

Is this the 92 2500 350 ?

jarhead2001 · 03-21-2008, 07:49 PM

yes it is sorry about that

also is flashing with no inputs
just driving down the road and flashing

crabtruck · 03-21-2008, 08:41 PM

I'm assuming it started flashing because you jumped A to H.
If so, what you are really seeing is 1 long and three short (code 4)
RWAL only stores one code at a time for that year and will repeat it.
Reason that is good is because sometimes the first flash count is wrong but the repeats will be right.
Code 4 is a grounded Antilock Pressure Valve Reset switch.
Key off, disconnect the 4-wire plug from EBCM and ohm the C contact to ground.
Pull Stop fuse for 30 seconds.(Clears code)
Key on, measure the voltage on the module's 4-wire pins from "C" to "D".
If you get 4v or more the pressure valve is a problem.
If zero volts, the ECBM may be toast.
Check your wires good and verify that code before spending money.

crabtruck · 03-21-2008, 08:42 PM

Just saw your edit, may be whole other thing - check wires.

jarhead2001 · 03-22-2008, 06:37 PM

crabtruck
i read your post on a similer issue on a gmc and tried your input (the code quit flashing) i unpluged the parking brake wires light stayed dim, next unpluged the one wire from the al block light stayed on, last the rwal upper plug and the light went off.
Im asuming that most likly the brake controller is bad.

thanks Justin

03-21-2008, 07:04 PM	#1
jarhead2001 Full Member Join Date: Mar 2008 Posts: 28	Brake service light My brake service light started flashing 3short flashes and one long flash dose anybody know what this means thanks justin

03-21-2008, 07:49 PM	#3
jarhead2001 Full Member Join Date: Mar 2008 Posts: 28	yes it is sorry about that also is flashing with no inputs just driving down the road and flashing Last edited by jarhead2001; 03-21-2008 at 08:20 PM.

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03-21-2008, 07:30 PM	#2
crabtruck Senior Member Join Date: Jul 2007 Posts: 1,464	Is this the 92 2500 350 ?

03-21-2008, 08:41 PM	#4
crabtruck Senior Member Join Date: Jul 2007 Posts: 1,464	I'm assuming it started flashing because you jumped A to H. If so, what you are really seeing is 1 long and three short (code 4) RWAL only stores one code at a time for that year and will repeat it. Reason that is good is because sometimes the first flash count is wrong but the repeats will be right. Code 4 is a grounded Antilock Pressure Valve Reset switch. Key off, disconnect the 4-wire plug from EBCM and ohm the C contact to ground. Pull Stop fuse for 30 seconds.(Clears code) Key on, measure the voltage on the module's 4-wire pins from "C" to "D". If you get 4v or more the pressure valve is a problem. If zero volts, the ECBM may be toast. Check your wires good and verify that code before spending money.

03-21-2008, 08:42 PM	#5
crabtruck Senior Member Join Date: Jul 2007 Posts: 1,464	Just saw your edit, may be whole other thing - check wires.

03-22-2008, 06:37 PM	#6
jarhead2001 Full Member Join Date: Mar 2008 Posts: 28	crabtruck i read your post on a similer issue on a gmc and tried your input (the code quit flashing) i unpluged the parking brake wires light stayed dim, next unpluged the one wire from the al block light stayed on, last the rwal upper plug and the light went off. Im asuming that most likly the brake controller is bad. thanks Justin