DBW Cruise control wiring
#1
DBW Cruise control wiring
What are the requirements to make it work? I am feeding +12 v to the cruise control on switch signal. A +12v momentary signal to the set/coast input. The TCC signal to the PCM is getting +12v until the brake pedal is depressed. But the cruise will not engage. I do not have the stop lamp switch signal hooked up, but that should not be a problem since it is just there to shut the cruise down right?
I am running a TH400 trans could that be an issue? I have a VSS signal being sent to the PCM and the trans codes are disabled in the PCM. Its out of a 2003 chevy suburban.
I am running a TH400 trans could that be an issue? I have a VSS signal being sent to the PCM and the trans codes are disabled in the PCM. Its out of a 2003 chevy suburban.
#3
VSS is taken care of, I have a 93 caprice rear axle with the ABS sensor in the pig. Its sending a 22 pulse per rev signal to the PCM and the PCM was reflashed with HPTuners so the PCM is seeing the correct speed.
The N/C brake switch is hooked up and operational. I didn`t hook up the N/O switch because the buick cruise control switches already have their power hooked up through a brake switch. Figured the N/O switch wasn`t going to see power anyway till the brakes are depressed so I didn`t think that would be an issue getting the cruise to engage without it. I know the N/O switch is needed to shut the cruise off, but I wasn`t worried about that, cause when I step on the brake the whole cruise system loses power. Maybe I`ll try hooking it up tomorrow just for the heck of it.
The N/C brake switch is hooked up and operational. I didn`t hook up the N/O switch because the buick cruise control switches already have their power hooked up through a brake switch. Figured the N/O switch wasn`t going to see power anyway till the brakes are depressed so I didn`t think that would be an issue getting the cruise to engage without it. I know the N/O switch is needed to shut the cruise off, but I wasn`t worried about that, cause when I step on the brake the whole cruise system loses power. Maybe I`ll try hooking it up tomorrow just for the heck of it.
#6
TECH Enthusiast
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so far the brake light circuit on my 67 pickup (2 bulbs total) has worked fine and my 89 caprice (4 bulbs).
original trucks, it used the circuit to the 3rd brake light, called CHMSL or (center high mounted stop lamp).. you'll see the wire called CHMSL feed circuit.
also, hopefully transmission type in the programming is still set to 4L60E and torque reduction during shift was set to 0. Setting trans selection to MANUAL trans will require PCM to have a clutch pedal switch input..which goes into the PCM on a different pin then TCC Brake switch....its the same signal...12v+ when pedal is released...and it opens the circuit when you press the clutch pedal.
original trucks, it used the circuit to the 3rd brake light, called CHMSL or (center high mounted stop lamp).. you'll see the wire called CHMSL feed circuit.
also, hopefully transmission type in the programming is still set to 4L60E and torque reduction during shift was set to 0. Setting trans selection to MANUAL trans will require PCM to have a clutch pedal switch input..which goes into the PCM on a different pin then TCC Brake switch....its the same signal...12v+ when pedal is released...and it opens the circuit when you press the clutch pedal.
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#9
You could wire in a hidden CHMSL. All the PCM cares about is that it has the correct resistance to ground. An 1157 should have ~6 ohms of resistance so you may be able to hook up 2 10ohm resistors in parallel (= to 5 ohms of resistance) to ground and get it to work.
#10
I tied a 1157 into the circuit, the cruise went to working perfectly.
Now if I could keep that light from coming on under the dash when I
push the brakes.
I'll see if I can come up with some resistors.
Thanks everyone for all the help.
Malcolm
Now if I could keep that light from coming on under the dash when I
push the brakes.
I'll see if I can come up with some resistors.
Thanks everyone for all the help.
Malcolm
#11
TECH Enthusiast
iTrader: (3)
You should probably try a few different light bulbs. Trying to match the resistance of the 1157 with resistors, you'd need some fairly high wattage resistors. I found some specs for the 1157 bulb and some others...
http://cybrvanr.tripod.com/bulbspec.htm
the CHMSL used smaller bulbs then the 1157, I would image you could try a smaller bulb and it would work.
OHMS = volts / amps
or
OHMS = volts*volts / watts
http://cybrvanr.tripod.com/bulbspec.htm
the CHMSL used smaller bulbs then the 1157, I would image you could try a smaller bulb and it would work.
OHMS = volts / amps
or
OHMS = volts*volts / watts