Where is the ground for the EVAP selinoid and ABS on 2005 GMS Sierra

If you don't have wiring diagrams,can't read them,&
or work on your own vehicles & their technology,then
a repair shop or different dealer, is you only option,that
question you knew the answer to

ABS system has nothing to do with base brake operation . ABS light on ? There are DTC'S - diagnostic trouble codes ,have codes checked ! No it's not a ground issue .

P0446 Gmc Evaporative Emission Vent System Performance

possible evap. overflow tube is clogged and allowing water to back-up into your floor

Just wanted to get you this GMC update for your vehicle before you replace that sensor ,, and unless you have the special tool , you can't do it either,, It requires that tool and they have made it so it needs to be done by them, which at that time they will set the system up again,, ,,,A poor electrical ground under the battery tray may cause the ABS warning light to illuminate. cleaning and properly securing this ground and also the main ABS ground on the frame rail below the drivers door may be necessary.

Well, you have an issue. I wouldn't say that it is the GMS, but it could be. The issues you are seeing could also come from low fuel pressure caused by a number of things from the little filter in the high pressure regulator to issues with the low pressure regulator. The frequency (HZ) thing is a little confusing---all it is saying is that the GMS isn't seeing the amount of requested fuel (requested by the AF ECU) passing through the sensor. If you have a mechanic that can scan the AF ECU, then the thing you want to look at is the requested gas flow v.s. the flow reported by the GMS. These two numbers should track each other. Sometimes the car sets a low frequency code when first trying to start as there just isn't enough NG arriving at the GMS during cranking. In any event, two things. Usually the GMS doesn't cure itself--so if it is running OK one day and not the next--it may be a fuel pressure issue. If you have, or can get a copy of the service manual supplement for any CNG Cavalier from 1999 through 2002, the procedures for checking fuel pressures can be used for your car. It is important to check the intermediate fuel pressures (at the entrance to the low pressure regulator) with the car under load. Also, follow the flow charts in the manual for diagnosis of the codes you received.

Pretty common problem with these. Here's a guide to learn how to fix GM instrument clusters yourself, I used it to fix mine and it worked great.How to guide for Envoy instrument cluster repair

There was a TSB on this issue with your Sierra, a faulty or dirty ABS sensor is the cause of this problem. The fix is simple, just clean the ABS sensor at the front hub with brake parts cleaner and inspect the wire leads. At worst you may have to replace the sensor it self. Good luck

P0446 is evap system problem. Could be a wiring issue or EVAP (Evaporative emission) canister purge valve or a problem with the ECM (engine control module) Without going through all the test procedures for this problem it is hard to tell what could be wrong with the system. We however find that most of the time it is the valve it self and have changed many of them especially if they have been on dusty roads a lot.

Hi there,

You should first of all check the fuse for the abs under the hood. If that is ok, then get ready to fork out a couple of thousand dollars to fix it. It is probably the abs actuator, due to a speed sensor malfunction. Both will need to be replaced. Don't bother calling Nissan, they will not help with this issue.

yeah it sounds like it is sticking,,,i know some of the GMs have aoring seal in the thermostat and over time it gets stuck inside the thermostat and causes weird issues