I just swapped gauge cluster on my 03 Monte Carlo LS with a gauge cluster from a SS how can I make the oil gauge work I know I can get a pressure switch for a gauge and new connecter but where would the second wire go I would really like to make it work thanks. PS yes it's a 3.4

 

I don't believe you can make it work. Most people just put a circular logo in that spot.

 

I've read many people say it won't work, but I've never read of anyone trying it. I'm not here saying it will work, but my curiosity gets to me. My old '94 Grand Am was fortunate enough that to do a cluster swap and make the oil pressure gauge work took a simple matter of swap the cluster and a the oil pressure switch needed swapped for a sending unit. Outside of that, perfect, everything worked.

Now, these Montes are far more modern then the old '94 Grand Am, in theory the PCM might be more "aware" and use the pressure sending unit/switches differently. Just for giggles, I looked up the PCM connector pin outs for the 3400 vs the 3800. Both use a TAN/BLK wire on pin 19 for the Oil Pressure Switch Signal (so no additional pins between the two).

Second, attached are screen shots of the connector views between the two different oil pressure units. Only difference is one has a single pin and the other has pin out for 4 pins, but only has a signal wire and a ground. Sadly, I don't know how else to confirm this, but from what I'm seeing, it's a gamble.... Get the correct switch and the connector, wire in the new connector and tie it to a ground (no, the ground does not go to the PCM, so it suggests that GM simply piggy-backed the required ground with another one running in an adjacent wiring harness). If the signal is nothing more then a pass through, then just like my old Grand Am, this will work.

Again, I've never read of anyone trying it, just people claiming it cannot be done, so if you try it and it works, I'd love to read about it

EDIT: I looked up the ground circuit. If you want to be "true" to GM's design, the ground ciruit used on both versions of the cluster is tied to pin 16 on the PCM, a BLK/WHT wire. But again, it's a ground, you can supply ground by tapping into any adjacent ground. I also looked up the connector view for the cluster. It's the same connector for both versions. I assume all the data from the sensors goes through pin A7 (the Class 2 serial data connection), as it does NOT get individual sensor data. Again, I'm willing to bet the cluster sorts out what ever data is received from that pin. So what ever oil pressure data is sent (be it on/off or an actual value) is probably passed along that data stream. If the PCM requires any alteration (such as a change via tuning), I cannot find it in the tools I have available. If this was my project, I'd try it for the heck of it. The WORST that happens, it does not work, you pull the sensor you put in and go back to the original one (no need to remove the connector since the pi required for both is the same and the connector is keyed the same).

 

So did you get it to work I'm thinking of doing the same thing

 

Another member tried the steps I outlined, sadly that did not get the oil gauge working. My guess is that the PCM/computer is configured for what type of oil pressure device is being used and sends either on/off or a current oil pressure value depending on what it's programmed to expect. If that is truly the case, to my knowledge none of the tuning devices have that setting available to adjust.

I'm still confident their is a way to make this mod work as a "plug and play", but it requires more understanding of what's going on from a software stand point.

 

Oh ok well I installed it anyway but I have a small problem everything works but the park break light is on when I turn the car on I put the key foward to listen to the radio and it's off but I press the park break and it turns on normal

 

Driving to work this morning my low oil pressure light came on with all the ding ding dings, very annoying, pulled over checked oil level all good, restarted symptom gone, came back few moments later, continued to drive to work after work way home symptom never returned. Anybody experience similar symptoms? suspect electric/electronic glitch. Currently gauge works fine shows great oil pressure. Also my ebrake was going to the floor not working figured out how to adjust cable understand it has drum within the disc brake rotor how the heck can it wear down to the point of using full range of adjustment when it is static? Maybe PO was doing ebrake turns.

 

When you guys did the swaps how did you change the mileage to match up with the old cluster? I acquired an SS cluster at the junk yard today and was interested in doing the swap

 

By law, your supposed to get that registered in some way.. You cant ever change the actual mileage in the cluster, just register it as changed..

 

Actually its well within the law to change a replacement gauge to reflect the actual mileage of the vehicle, its unlawful to change mileage to a lower incorrect value to sell. When a refrubeshed unit is installed at gm it is programmed to the mileage of the old cluster, I'm just not sure how they do it