06 Silverado problems

[Booty.80]

My 06 Silverados knock sensor went out while driving a month ago. Right before my truck died,  all electrical in my truck started flashing. I had to get it pulled home. I couldn't turn the steering wheel & the brake pedal wouldn't push down. I changed both knock sensors & wiring harness, put everything back in its place, & now truck wont start(she tries tho) & the obd2 reader is giving 3 codes, c0035, c0048, & c0055. I tried bleeding the fuel line to no avail. I haven't even attempted to fix the new problems. I'm at a lost, dont know where to start. Help

[carkhz316]

Those are chassis codes and won't keep your engine from starting. When you say it tries to start, what do you mean exactly? Does it crank but not fire, or does it sputter as if it's about to start? Have you checked fuel pressure, spark, etc? 

[Jsdirt]

You've more than likely got a wiring problem based on the symptoms when it was running, and your codes. 2 of them are for ABS issues, and one is for pedal travel - did you pop a brake line? Is the pedal going straight to the floor? Without the engine running, the power assist for both the brakes and steering will not work, so effort will be high. This is a separate issue from the no-start.

 

Start with anything you just touched - give the area a THOROUGH look-over. There may be a critical ground that was missed, or not tightened fully. If any module doesn't have full power and ground, you'll have all kinds of issues.

 

If that all checks out, move on to the battery - always start with the easy stuff first. Make sure the end of the ground where it attaches to the frame is CLEAN and TIGHT - same up at the battery end, and same with the positive cable, only you'll be checking where it bolts to the starter, alternator, and all along its way to the power distribution box. Check everything in between as well. If the jacket got nicked, there could be just 3 strands of wire with too much resistance ... but seeing that you have a 2wd I'm assuming you don't live in the rust belt, so this may not be as likely.

 

Let us know what you find.

[Doug_Scott]

Every gasoline engine has 3 requirements, fuel compression and spark.  You will notice there is no mention of computer.  Ignore any suggestions to skip over those three requirements. 

Check fuel pressure at fuel rail. 

Check spark at one spark plug wire and if those 2 circuits are working, do a compression check. 

 

You failed to provide even the most basic information.

What series is the truck? 

What engine? 

Is this truck equipped with hydaboost or just the standard vacuum brake booster/power steering pump?