Saturn Vue Steering Install

Gtstorey

Goblin Guru
Installed the Saturn Vue power steering unit and I’m running into the loss of data communication problem. Research on here indicates I should be able to install A 120ohm resistor on the data wires. It looks like I will connect wires 1/4 and 2/5 together and then connect the pairs with a 120ohm resistor per the picture? 2009 TC donor.
 

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ctuinstra

Goblin Guru
The 120ohm resistor is for the end of the line of the serial data. 1/4 and 2/5 should be already connected inside the PSCM to allow communication using the DLC (OBDII port). If they aren't connected, it's not going to have an effect on the PSCM but the DLC won't work. I'll bet the communication issue it the ECM or BCM is expecting a particular PSCM and you have installed a different one.
 

Gtstorey

Goblin Guru
Yes it won’t communicate plugged into the Saturn Vue PSCM. The Saturn Vue one doesn’t need to be tied in using the variable control with it. I’m trying to get the rest of the car to communicate without than original plug connected. It’s mentioned here
 
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ctuinstra

Goblin Guru
I'm surprised the BCM is okay without being able to communicate with it once it's removed. Yes, adding the 120ohm resistors terminate the end of the line so there is no reflection. You will want to connect the pairs as stated before so the DLC port still works.
 

ATMironov

Well-Known Member
I put a 120 ohm resistor between 1 & 4, and a second 120ohm resistor between 2 &5. I did not tie the two together.
All my data seems to be working correctly.
 

Gtstorey

Goblin Guru
I've got some resistors ordered so I guess I'll see if I can get it to work. From my reading up on it, I think I should be connecting it up like my first plan. According to the literature I found, I should be connecting the GMLAN + (aka as High) circuit 2500 and GMLAN - (aka as Low) circuit 2501 with the 120ohm resistor. I'll see if a can measure the resistance across the pins on the PSCM and see if that matches. Judging from wiring diagram, pins 1 & 4 are connected to each other and 2 & 5 are connected in the PSCM. I may have to supply power to the PSCM since the 120ohm resistor may be "switched".

Some good general info on GMLAN;

SECTION ‘X’ CONTENTS (aeswave.com)
 

DCMoney

Goblin Guru
Did you buy the variable assistance controller for the Saturn Vue EPS?

I have both of these and haven't had to add any kind of resistor since it was a plug and play device.


 

ATMironov

Well-Known Member
Did you buy the variable assistance controller for the Saturn Vue EPS?

I have both of these and haven't had to add any kind of resistor since it was a plug and play device.


Yeah, that’s the kit I bought.
Since the Vue EPS controller does not use the CANBUS and the Cobalt EPS did AND had the 120ohm resistors in it I’m really really surprised your communications are working.
does your OBD2 port work?
 

DCMoney

Goblin Guru
Yeah, that’s the kit I bought.
Since the Vue EPS controller does not use the CANBUS and the Cobalt EPS did AND had the 120ohm resistors in it I’m really really surprised your communications are working.
does your OBD2 port work?
Yeah no issues. I figured I would have to do the same thing as above but I plugged it in and didn't have any issues. 06 SS/SC for reference.
 

Gtstorey

Goblin Guru
Yes I have the kit also. I first tried to plug in the Vue with all of the Goblin connectors and got a no crank condition and getting a data logger to connect was problematic although it would occasionally connect . With the none of the Goblin connectors plugged in I could start it but had a MIL and I think it was in reduced power mode. With the main power connected to the Vue and the Goblin plugged into the Cobalt PSCM, it started without a MIL and just had a power steering message on the Instrument Cluster that cleared when I hit the DIC button.

The older Cobalts may have had their GMLAN components in a different order and the PSMC may have not been at the end of the chain which is where it needs the 120ohm resistor. It might even have had separate resistor that wasn't built into a module at all.

It looks like Brian74 is maybe using an 09 BCM and PCM so that may be why he had to add the resistor. I haven't read his entire build thread, but I did find where he bought the 09 modules.
 
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Gtstorey

Goblin Guru
The Cobalt PSCM does connect up 1/4 and 2/5 internally and are connected by a resistance of 120ohms. I’ve connected the wiring this way and I get the 60ohms resistance at the DLC the link I posted above says I should. Car starts as normal and no check engine light or IC readout of an issue. Now to drive it and confirm no problem and a review of how it works.
 

Gtstorey

Goblin Guru
No problem on the drives and my OBD2 speedometer worked so I think the 120ohm resistor connecting 1/4 to 2/5 is the correct way to go.

The Saturn Vue with the variable steering control is worth the effort. I would not say the steering is perfect but more stable. It mostly eliminated a sideways jerk that it would do when shifting under hard acceleration. I thought it might have been me not keeping the steering wheel perfectly straight and the increase in steering effort seems to make it smoother.

I wish it would actually turn down a little more before it cuts all assistance. Right now I’m as low as it seems to go with cutting of completely.
 

DCMoney

Goblin Guru
No problem on the drives and my OBD2 speedometer worked so I think the 120ohm resistor connecting 1/4 to 2/5 is the correct way to go.

The Saturn Vue with the variable steering control is worth the effort. I would not say the steering is perfect but more stable. It mostly eliminated a sideways jerk that it would do when shifting under hard acceleration. I thought it might have been me not keeping the steering wheel perfectly straight and the increase in steering effort seems to make it smoother.

I wish it would actually turn down a little more before it cuts all assistance. Right now I’m as low as it seems to go with cutting of completely.
I found I keep mine at the point right before it turns off as well.
 
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