Tow-Rig - 2003 Silverado 1500HD - Quadrasteer

jirwin

jirwin

Goblin Guru
Starting a separate post as to not clog up my build thread with more truck stuff.

This is my new (to me) 2003 Chevrolet Silverado 1500HD. 6.0L, 4L80E, and (working) quadrasteer! Its from Texas so its mostly rust free. Looking forward to modifying this to eventually make it my DD and replace my 2019 Tacoma.

ToDo List:
  • Headlights, taillights, etc
  • Sound system
    • Add bluetooth to existing stock radio
    • Add my old set of subs that are just lying around because they wouldn't fit in the Taco
  • Fix cracked dash (yay Texas heat) with a skin
  • Fix sticky locks
  • Take a look at million butt splice jobby they did on the throttle body. Its occasionally throwing me an ENGINE POWER REDUCED with a TPS code. Likely a crappy connection
  • Lower the rear a bit so its more level (BelleTech lowering shackle)
  • Cheap exhaust to fix the header leak, thinking Speed Engineering
  • Truck Norris Cam + Value Springs
  • Tune for cam
  • Remote electric exhaust cutout for cam
  • Shock for slow open tailgate (one of the few things newer trucks got right!)
  • Tires! current ones are mismatched and nearly bald. I might end up going for two sets and using these stockers as snow tires. All depends on what's available for 16" rims
Maybe List:
  • NV4500 Manual swap
  • SS Front Bumper Cover
  • Roll pan? Probably a bad idea for towing, but I love the look
  • Tonneau cover
  • Backup camera
  • Locking tailgate
46931
 
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jirwin

jirwin

Goblin Guru
Welp, fingers cross oil pressure is ACTUALLY good. The sensor is bad. Its pegged max even engine off. I thought it might just be high until warm, but didnt notice it was max when not running. Looked at it in HPTuners and its reading 130psi (gauge goes to 80) no matter what. New sending unit on the way. Went with GM because I hear sensors you don't really want to cheap out on
 
Rttoys

Rttoys

Goblin Guru
To add to your list.

H2 wheels with 285’s. Direct fit and the center cap will adapt.
’06 tow mirrors.
IMG_5799.jpeg
IMG_5808.jpeg
 
Rttoys

Rttoys

Goblin Guru
Oh. And don’t lower the rear, crank up the front. The t bars are weak from age, turn the bolt on the dog bone to bring the front up to level.
 
jirwin

jirwin

Goblin Guru
Idk, the wheel gap really bugs me. I'm never going to offroad it since its 2WD, so I think I'm going to lower the rear a little and see how it does. I don't want to slam it, but being lower and level-ish will be good enough for my purposes
 
G

Gtstorey

Goblin Guru
I thought this a tow rig. Put a trailer on it and it will be level, level without a trailer will be nose up with a trailer.

Did people worry about wheel gap before car shows on tv or internet? I never heard anyone say anything about that before then.
 
Rauq

Rauq

Goblin Guru
With lowering the rear, changing caster in the rear steer system is a possibility to keep in mind.
 
jirwin

jirwin

Goblin Guru
Gtstorey said:
I thought this a tow rig. Put a trailer on it and it will be level, level without a trailer will be nose up with a trailer.

Did people worry about wheel gap before car shows on tv or internet? I never heard anyone say anything about that before then.
Click to expand...
It might be, but I haven't tried yet. I planned on leaving it with a little rake, but not the 4" of rake it currently has.

Rauq said:
With lowering the rear, changing caster in the rear steer system is a possibility to keep in mind.
Click to expand...
Yeah, I'm aware it could change angles. I'll pay attention when doing it. The drop is adjustable 1"-3" so I can play around with it a bit.
 
jirwin

jirwin

Goblin Guru
The oil pressure sensor was reading max all the time. Replaced with new GM sensor. Man is the worst job I've ever had to do. What a pain. Picture is of a 6" extension. ALLLLL the way at the back, under the firewall overhang. Running just under 40psi at cold idle though, so its at least acceptable.

signal-2024-04-28-19-06-31-741.jpg
 
jirwin

jirwin

Goblin Guru
Theres a little tab from the casting of the intake manifold that digs inton your wrist when reaching back too. Well, was. Sawzall took care of that issue after I started bleeding lol
 
Rttoys

Rttoys

Goblin Guru
The “HD“ models are a little easier. The cab is off the frame/engine a bit more than the 1500/2500.
 
jirwin

jirwin

Goblin Guru
Well now that the car is driveable again, I'm back to fiddling with this. Right now I have 2 or 3 issues.
  • REDUCED ENGINE POWER from either Throttle/Pedal Position sensor short or something
    • This is the most pressing and annoying issue. I can shut the truck off for 30 seconds and its back to normal for an indeterminate amount of time
  • Quadrasteer will occasionally just turn off
    • I think this is caused by a wire I see they jumped to the back
  • Brake Controller short (I think)
    • On occasion the ABS and ebrake light will come on and ding for a second or two when driving. Cleaned up the grounds for it recently, but it didn't fix it
Since the TPS issue is the most pressing, so I think I'm going to work on that next. My hunch is that this issue caused the trade in to the dealer. The throttle body looks new, and it has a new pigtail thats butt spliced into the main harness. My hunch says the connector and TPS are fine. My plan is to cut the wires before the butt splices, solder in my own harness, and run it directly to the ECU or wherever it goes. Do it similar to the Goblin harness where you cut the wire a few inches from the ECU plug/connector and solder in the 8 wires. That accomplishes fixing the butt splice issue AND rules out any weird shorts in the harness itself (that I don't want to trace). I will also be trying to get a list/map of all grounds to try and find them and make sure they're good. If that fails, I think I'll be jumping into the Pedal Position circuit or a new TPS.

Current codes:
Code: 
0x10: P0220 - Throttle/Pedal Position Sensor/Switch B Circuit (Current, History)
0x10: P1515 - Electronic Throttle System Throttle Position (Current, History)
0x10: P1516 - Throttle Actuator Control (TAC) Module Throttle Actuator Position Performance (SES, Current, History)
0x10: P1518 - Electronic Throttle Module to PCM Communication (Current, History)
0x10: P1571 - Traction Control Torque Request Circuit (Current, History)
0x10: P1689 - Delivered Torque Circuit Fault (Current, History)
0x10: P2135 - Throttle/Pedal Position Sensor/Switch A/B Voltage Correlation (SES, Current, History)
0x10: U1041 - Loss of EBCM Communication (History)
0x10: U1301 - Class 2 Short to Battery (History)
 
G

Gtstorey

Goblin Guru
is it a GM throttle body or aftermarket?
I would try and confirm that no one has tried to change throttle settings in the tune.
No pedal commander type device installed?

On top of that, I always recommend starting with the OEM diagnostic for the codes, although it can be hard sometimes with intermittent problems.
 
jirwin

jirwin

Goblin Guru
No pedal commander or anything. Unsure om brand of TB, but I'll look. What do you mean by OEM diagnostic? Use Tech2 instead of HPTuners?
 
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