Ok so for the last couple of weeks, i've been having some random issues with my 2001 Blazer.

It started with a check engine light. I brought the truck into a dealer, and they came back to me with a PO453. Said my PCM was toast and needed replacement. I questioned them more and they said that the 453 was and excessive high voltage and that my PCM wasn't sending a 5v reference signal... That doesn't make sense to me, because how could it be popping a "high voltage" code and yet not sending a voltage at the same time...?

So, a couple of days later I borrowed my neighbors code reader to check it myself, and it had a PO453 and a PO446. Ok so, high voltage and evap valve. Gotcha... I also started noticing that my fuel gauge would bounce around alot, even when the vehicle is parked and hasn't moved. Almost like a weird voltage issue and the brake and abs light will sometimes come on when this is happening.

I didn't have the opportunity to get this fixed right away, because I was moving, but now that I have settled down and I have the time to work on the truck another problem has surfaced.

Now my ABS kicks on while on dry pavement now and then. The ABS light will come on, then go out, and the abs will sometimes turn on and sometimes won't. SO I borrowed another code reader and along with the 446 and 453 codes, now i'm also getting ABS codes CO221, 223, 226, 265, and 281...

Super long story short, do you guys think there could be a linked problem anywhere in here? Like is there a ground pack the ABS and Evap system uses anywhere or i'm I just lucky enough to multiple problems with my blazer?

So to recap, ABS acting funny, fuel gauge acting funny, and evap acting funny. Any common connections???

OH and the fuel pump was replaced like 2 years ago if that helps at all...


Thanks for any help.

 

C0221 - Right Front Wheel Speed Circuit Open
C0223 - Right Front Wheel Speed Signal Erratic
C0226 - Left Front Wheel Speed Signal Missing
C0265/C0266 - EBCM Motor Relay Circuit
C0281 - Stop Lamp Switch Circuit

Concerning the ABS codes, I would check into the front wheel speed sensors, test the wiring, test the sensors (info HERE), and you should be able to determine the problem. Another member had very similar codes and supposedly cured the problem by replacing a hub which came with a new WSS.

P0446 - Evaporative Emission Control System Vent Control Circuit
P0453 - Evaporative Emission Control System Pressure Sensor High Input

You might want to search for these two codes and see what others have come across with them. Typically, the P0446 code is a faulty vent solenoid back behind the tank.

With the fuel gauge, check out the link below:
98+ Fuel Gauge Diagnosis

 

Thanks for the reply. I understand what all the problems are and what all the codes mean and stuff. What im trying to figure out is if there is a common ground or something between them all. Instead of trying to troubleshoot them all individually and replacing sensors and all that jazz, im trying to figure out if they share like a common ground plate or something that could be causing all these issues at the same time.....

 

Here's a thought... Look at the diagnostic links I provided and compare the wiring diagrams!

BTW, testing the front sensors is free if you have a digital multimeter (which any DIY'er should have). And it could be a simple cleaning that is necessary or a broken wire that needs to be reconnected. Pretty simple stuff can cause these problems, but if you want to focus on one direction, have at it.

 

My 98 was sitting in a garage for 2 years and also has gremlins. The more I use it the more they dissappear. My shifter display(P,R,N,D...), odometer, airbag, check engine,lights have been intermittent. Pulled the dash apart, cleaned,and checked connections. Used dielectric grease on reassembly, seemed to help alot. Also changed radio while I was in there.