AL Posted February 27, 2012 Report Share Posted February 27, 2012 Carried over from the Whatever thread... I have the access cover off and am checking to see if the sending unit is working properly... With the connector plugged in, I poked through the wires and got an open circuit... However when I pulled the connector off and went straight to the pins, I am seeing a resistance of 127.8 (around 1/2 tank)... Spec is 40 ohms - 250 ohms... Im right in the middle... Gauge reads empty all the time... So where do I go from here? Quote Link to comment Share on other sites More sharing options...
AL Posted February 27, 2012 Author Report Share Posted February 27, 2012 Usually a open condition will cause a Full all the time reading. Alright, thats good to know... maybe cluster/bcm? How do I check these? Checking sensor inputs and outputs with the multimeter? Its possible I had a bad connection in the wiring when I hooked them up to the sending unit the first time When mine was bad in the GP I would sometimes get a "full" reading then other times I'd get an "empty" reading. The metal tab that swipes along was actually gone so I'm not sure how the tank would change levels but it did. When I start the car, it reads full for 10 seconds, then shoots to empty... I have never seen it act any different than that Quote Link to comment Share on other sites More sharing options...
AL Posted February 27, 2012 Author Report Share Posted February 27, 2012 [/font][/font] Quote Link to comment Share on other sites More sharing options...
AL Posted February 27, 2012 Author Report Share Posted February 27, 2012 Its looking like its probably the cluster... Does the dealer have to reprogram the cluster or do the miles get stored in the BCM and I can just throw a different cluster in with no issues? Quote Link to comment Share on other sites More sharing options...
White93z34 Posted February 27, 2012 Report Share Posted February 27, 2012 I'd get a pinout for the cluster, it MAY be BCM controlled since a good bit of that regal is databus driven. IIRC Cluster saves milage, not bcm. Quote Link to comment Share on other sites More sharing options...
iTurbo Posted February 27, 2012 Report Share Posted February 27, 2012 Out of curiousity, is it possible to have the mileage in the cluster reprogrammed? Because I still got to get a replacement cluster for my Regal GS and I'm hoping I can get the mileage to be correct again. Quote Link to comment Share on other sites More sharing options...
White93z34 Posted February 27, 2012 Report Share Posted February 27, 2012 There are all sorts of shops that can do it, some local some mail out. What is wrong with you cluster? Quote Link to comment Share on other sites More sharing options...
runt Posted February 27, 2012 Report Share Posted February 27, 2012 Al, what you said about starting the car on FULL then wait about 10 seconds and it goes to EMPTY is EXACTLY what my GP did. Now, sometimes it would do other strange shit but 9.5 time out of 10 it did EXACTLY that. The float is connected to a small printed circuit board which sends the proper voltage to the dash gauge. All that the float really does is move a small metal bar which gets eroded by the crappy gas we use. I can't think of the proper names but I can almost guarantee that it's the exterior of the sending unit and you are missing that small metal "wiper". Quote Link to comment Share on other sites More sharing options...
iTurbo Posted February 27, 2012 Report Share Posted February 27, 2012 (edited) White93z34There are all sorts of shops that can do it, some local some mail out. What is wrong with you cluster? None of the backlighting would light up and all the LEDs for the DIC and odometer were very dim or wouldn't light at all. I think I've found that the headlight switch is the culprit behind the no backlight issue. On the LEDs, I found there is a common problem with the solder joints on some of the resistors on the backside of the circuit board can fail. When I removed my cluster, most of them fell right out! So I went to Radio Shack and got some replacements that were suggested on this forum and attempted to solder them in but I ended up messing the circuit board up bad. Like so bad it's not even fixable. I can solder wiring but circuit boards forget it. So I'm still looking for a cluster circuit board and a headlight switch and won't be able to drive the car at night until then. Awsome that I can get it reprogrammed though. Sorry about the OT post...carry on:p Edited February 27, 2012 by iTurbo Quote Link to comment Share on other sites More sharing options...
AL Posted February 28, 2012 Author Report Share Posted February 28, 2012 (edited) Iturbo, its fine, its good information that I didn't know... also, I know the Buick dealer can reprogram the mileage for you as I was going to order a new cluster and have them do that... Edited February 28, 2012 by AL Quote Link to comment Share on other sites More sharing options...
AL Posted February 28, 2012 Author Report Share Posted February 28, 2012 When I get home, ill pull my pump out and check the tab your talking about... I'm glad you posted that Jeremy Quote Link to comment Share on other sites More sharing options...
AL Posted February 28, 2012 Author Report Share Posted February 28, 2012 Well jeremy, I just proved the sending unit good by pulling the pump and checking the resistance all the way from empty to full... Works great... so it looks like the cluster is getting replaced in the next couple of days Quote Link to comment Share on other sites More sharing options...
AL Posted February 28, 2012 Author Report Share Posted February 28, 2012 Heres what Ill be ordering in the AM http://www.ebay.com/itm/SALE-REBUILT-GM-BUICK-REGAL-INSTRUMENT-GAUGE-DASH-SPEEDOMETER-CLUSTER-PANEL-/370575670333?pt=Motors_Car_Truck_Parts_Accessories&fits=Make%3ABuick%7CModel%3ARegal&vxp=mtr&hash=item564807fc3d#ht_1157wt_1189 Unless I can somehow prove the BCM is bad but I dont think the sending unit info goes through the BCM, I think its the PCM Quote Link to comment Share on other sites More sharing options...
alec_b Posted February 28, 2012 Report Share Posted February 28, 2012 Looking up a diagram, will return. Quote Link to comment Share on other sites More sharing options...
alec_b Posted February 28, 2012 Report Share Posted February 28, 2012 I'm back. Quick look of the diagrams: The only thing that gets an ACTUAL fuel level signal is the PCM. Everything else is on the serial line. Neither the BCM or the cluster receive a direct fuel level signal. The purple wire in your harness is the signal going from the fuel level sender to the PCM. If I were you, I'd probe this wire with both the sending unit and the pcm unplugged and see if you have a short to ground. Also, if you have access to a scanner just scan and see what the PCM is seeing for calculated fuel level. If the PCM says 1/2 tank, like your meter indicates, then you know you have a cluster issue. Better yet, with the proper scanner you can just access the cluster and see what IT'S seeing. That'll put the nail in the coffin for sure. Quote Link to comment Share on other sites More sharing options...
AL Posted February 28, 2012 Author Report Share Posted February 28, 2012 I am onto something!! I am checking continuity between the fuel pump wires and the pcm wires and so far its looking like I have a broken wire somewhere... I am not giving up until I have this diagnosed Quote Link to comment Share on other sites More sharing options...
alec_b Posted February 28, 2012 Report Share Posted February 28, 2012 Awesome! Did you find something on the purple wire? No continuity? Or a short somewhere? Quote Link to comment Share on other sites More sharing options...
AL Posted February 28, 2012 Author Report Share Posted February 28, 2012 Well Fuck me running... I found a broken wire in the engine compartment and fixed it and start it up and I STILL dont have a working fuel gauge... NOTHING CHANGED... Damn it!! All I know now is the PCM is getting the fuel level signal... The next step is obviously finding out what the gauge cluster is seeing... However, that looks to be databus signal... But I can pretty much narrow it down to that as I know the PCM is getting the signal... It really threw me off as the connector pinout for the PCM does not show the wire for the fuel level sensor... But its pin 69 on the clear connector... I only have a small code reader scanner, nothing like what I would need to see cluster data information... I was really hoping I had fixed it Quote Link to comment Share on other sites More sharing options...
AL Posted February 28, 2012 Author Report Share Posted February 28, 2012 Awesome! Did you find something on the purple wire? No continuity? Or a short somewhere? No continuity... I fixed it and the traction control wire that was broken and it still reads full for 10 seconds and then shoots to empty Quote Link to comment Share on other sites More sharing options...
alec_b Posted February 28, 2012 Report Share Posted February 28, 2012 No continuity between the fuel pump connector and the PCM connector? Worse comes to worse, get yourself a long piece of test lead and splice it into the harness. Doesn't have to be pretty but it would help to test. Just cut the purple wire at the FP harness and at the PCM and wire in a long piece of spare wire. Then see if the gauge works. If not, I'd say it's for sure a cluster issue, because if it was a data issue I'd assume you'd have issues in other modules as well. Quote Link to comment Share on other sites More sharing options...
AL Posted February 28, 2012 Author Report Share Posted February 28, 2012 (edited) I found and fixed the broken wire, but I still dont have a working fuel gauge... I found the wire broken under the cruise control module... It looked like it had rubbed against the AC line and eventually rubbed through... But I fixed it, taped it up and moved it away from the AC line Edited February 28, 2012 by AL Quote Link to comment Share on other sites More sharing options...
iTurbo Posted February 28, 2012 Report Share Posted February 28, 2012 Hey thanks for that eBay link AL. I tried to find a cluster on eBay about a week ago and couldn't find anything. It would be nice to get one in the mail and know that it's going to work and light up and have it already reprogrammed for my mileage as well. Quote Link to comment Share on other sites More sharing options...
AL Posted February 28, 2012 Author Report Share Posted February 28, 2012 Yep, I just got off the phone with them and am getting a new one here soon Quote Link to comment Share on other sites More sharing options...
alec_b Posted February 29, 2012 Report Share Posted February 29, 2012 Well if you fixed the broken wire from the sender to the PCM, it sure seems like it's a cluster issue. It's too bad you don't have a scan tool to see what's all going on with the modules. Quote Link to comment Share on other sites More sharing options...
AL Posted February 29, 2012 Author Report Share Posted February 29, 2012 I just ordered the cluster... if That's not it, its the pcm Quote Link to comment Share on other sites More sharing options...
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