Ram Air IV

I have a Firebird -68 with a LQ9/4L60E drive engine. Since it have DBW I would like to use the Cruise control possibility. I have wired according to the diagram for the LQ9 engine but it does not work. In the wiring diagram there is a cable from the PCM (C1, 58 cable 1049/1036) that is connected to Instrument panel cluster. Is this something that I need and what is it doing?

Anyone who has experience from this ?
M

locrzn

iTrader: (9)

I would like to have mine working also. The original builder of the wagon said he couldn't get his to work and it has something to do with the body modules not being in place. I've got a guy that is a gm tech going to check into it for me. I'm getting ready to switch mine out from a 4.8 to 6.0 ly6 with ported l92 heads. If I find something out during the swap I'll post it and hopefully someone else will post something also. You have a good looking ride.

oldgoat69

I have the same issue. I wired the cruise per instructions and diagrams, nothing. I have tested all of the wires for continuity, all good. Any other ideas I am all ears. Good to know it is just not me.

sierrac3_s2000

iTrader: (6)

I haven't personally wired one like this so this information may or may not be correct. I beleive that all the serial data to the instrument cluster is for is to illuminate the Cruise On light. If I'm not mistaken I believe that each function in the turn signal stalk has a different resistance value. I know some are wired that way. Maybe you could check an existing vehicle to see.

Also do you have the serial data connected between the TAC module and the ECM? Also do you have the brake switch connected to the TAC module.

Ram Air IV

Since it was a couple of year since I did the swap I will check that all the cables are at the right position. But I am pretty sure that all cable except the one to the instrument cluster has been connected. Fix this should not be rocket science ! or is it .....

aknovaman

iTrader: (7)

You don't need the cruise light to make it function. Simply temporarily hook up a toggle switch and a couple push button switches like the diagram. Since it is dbw you don't need to make any changes in the PCM file to enable it functionally. Be sure you have the tcc brake switch wired correctly too. This way of wiring it will first verify the PCM, file and basic wiring. If you use the factory column switch, the logic voltages are backwards. I have a HPT datalog config that I use to verify the switches and wiring is correct. Pm me you email and I can send it to you if needed. Fords have resistors for set and resume. Gm is simply voltage levels at the PCM pins.

BP Automotive

iTrader: (3)

As aknovaman said, you must have the TCC circuit hooked up for cruise to function. If you are using a manual tune you must have the clutch pedal position switch circuit functional also. Your problem most likely resides in one of these two circuits....

ls1nova71

iTrader: (4)

What year of engines are you guys using? The older gen 3's it will work, the gen4', not so much. Also depends on what you are using for a switch. If you're using an aftermarket like Dakota Digital or Rostra, you need to wire in relays to reverse the internal switches from normally closed to normally open. If you have the correct switch and it still doesn't work, make sure your brake switch is adjusted properly. Just because the lights come on when the pedal is depressed doesn't always mean the second set of contacts in it are fully closed when you let off of it. Try adjusting it so the brake lights don't come on as soon. I've seen this many times be the cause of inoperable cruise control. Also, if you are rinning LED tail lights, you neen to 'losd' the brake light circuit since they don't have enough resistance. If you need a cruise lever that will work without the relays, II have some that are redone and look nice and bolt on with a single screw like the older GM columns. I can get pics if anyone is interested.

Ram Air IV

I have 2002 engine (Gen 3). At the moment I use standard switches that I mounted on the gear shift panel since I don´t have the correct column switch. I will go back and verify that all cables are on the right place. TCC engagement would be possible to check via EFIlive since it is parameter that can be logged, right ?

KY Nova

iTrader: (1)

I'm not ready to even think about cruise yet, but I will someday soon I hope. Could you post a pic of your lever?

74novacustom

Im running a Dakota Digital HND-2 with my 04 LQ9 DBW, works great.

Ram Air IV

Thanks for the input, DD HND-3 would be something I should order ASAP

ls1nova71

iTrader: (4)

I'm out of town at the moment but can on monday morning.
The HND2 is the dash mounted switch and is the ONLY one that will work without relays. The HND 3 Will need relays.

oldgoat69

I have a 2003 LQ4. I have tried several different switch configurations without success. I have tracked and verified all of the circuits, mostly the TCC. I will give it another try this weekend if the monsoon abates.

locrzn

iTrader: (9)

I have a Dakota Digital Dash. I'll give them a call. Mine is a 2009 DBW, I'm already sick of driving mine on the interstate any highway without Cruise. It just sucks, guess I'm spoiled. Ha

62n62

iTrader: (17)

The company that makes the cruise control system for LS powered vehicles is Rostra. You can find them on the internet. Search "Cruie control".


I can get the setup have one on a 40 ford with ls motor works great

oldgoat69

I went back and rewired the switches per the diagram, and it still does not work. I am using rocker switch for cruise on and 2 momentary switches for set and accel. Any ideas?

ls1nova71

iTrader: (4)

So you have 12volts on the rocker switch and the momentary swiitches? How is your brake light switch wired? Did you try adjusting it in some to make the lights come on a little later?

Ram Air IV

So, as I understand cable 1320 (TAC C1, Pin 6), Stop Lamp Supply Voltage should be hot when apply brakes. Cable 420 (PCM C1, Pin 33) should work in reversed order, hot WITHOUT brakes applied, right ?
Since the brake switch on my car connect to earth when braking I have a relay connected to this that make it possible to invert the signal and use it for +12V on/off.

At the moment I have a momentary swith that apply +12V to TAC C1, Pin 14 and feed a 2-way rocker switch that I can toggle between TAC C1, Pin 4 (set/coast) and TAC C1, Pin 5 (resume/accel). Would that work?

LS1Nova71, why do I need relay for the HND2 and not HND3?

Magnus

ls1nova71

iTrader: (4)

You need an on/off switch to supply 12v to TAC C1 pin 14, not a momentary.and then momentary switches for the set/coast and resume/accel.

As for why the das mounted DD switch doesn't need relays, its because the switches in it are normally open, like a GM switch where as the turn signal lever DD switches are normally closed. Why they did that I have no idea but have seen a lot of people try to use the TS mounted switches and have problems with them. I'll try to find the thread that shows how to wire the relays.