V1 LeoZug's Montana Street Goblin - '05 Cobalt SS donor

[Leo Zugner]

Oh ok. I wasn’t sure if they were obvious. I’ll look them up today.

 

[Ross]

It looks like https://charm.li/Chevrolet/ is down today and yesterday. That was my main source for looking DTCodes up.

 

[Gtstorey]

It looks like https://charm.li/Chevrolet/ is down today and yesterday. That was my main source for looking DTCodes up.

An internet search for "GM DTC P####" tends to be accurate enough for initial thoughts, although at some point, some of them may need to be looked up for the exact definition in the service manual for confirmation.

First in the list P0223; P0223 GMC Code Meaning, Causes, Symptoms & Tech Notes (With Video) is a serious one that might cause the ECM to not let it start.

But we also need to know if these are current, pending or historic codes.

 

[Leo Zugner]

This is what I've found:

P0223 Throttle/Pedal Position Sensor/Switch B Circuit High Input
P0230 Fuel Pump Primary Circuit Malfunction
P0449 Evaporative Emission Control System Vent Valve/Solenoid Circuit Malfunction
P0452 Evaporative Emission Control System Pressure Sensor Low Input
P0463 Fuel Level Sensor Circuit High Input
P0641 5-Volt Reference 1 Circuit ECM, PCM
P1183 Supercharger Inlet Pressure Sensor Circuit Low Voltage PCM
P2138 Accelerator Pedal Position (APP) Sensor 1-2 Correlation ECM, PCM
P2228 Barometric Pressure (BARO) Sensor Circuit Low Voltage PCM

Seems like a few of these wouldn't matter and would be expected based on some stuff that was removed. Fuel Pump primary circuit malfunction seems like an issue. Or is that because the fuel pump isn't wired up yet?

 

[Ross]

A lot of Low Voltage on various sensors.
Makes me wonder if the Circuit 1, 5V system has an electrical issue that is dragging down the voltage below 5V.
P0641 5-Volt Reference 1 Circuit ECM, PCM

As far as the fuel pump goes... wire it in, and see if it fixes any of the OBDii DTCodes.

 

[Leo Zugner]

So this could be a silly question, but should I go ahead and wire up the new fuel pump to remove any potential issues with that? (hoping you don't say, "OMG you haven't wired it up yet!!!!!!)

 

[Ross]

Yes, I would wire it up... it needs to be connected eventually.

 

[Leo Zugner]

ok. I'll do that this evening. This all started when trying to confirm which wires were which for the pump but I'm pretty sure those are established now. Which of those codes do you think will remain but aren't important? Like the evap stuff maybe?

 

[Robinjo]

Evap. Codes aren't important
Is your Accelerator Pedal connected?
Hopefully wiring the fuel pump will resolve those

 

[Leo Zugner]

ok cool.

The gas pedal is plugged in. But I'll double check everything this evening.

 

[Gtstorey]

ok. I'll do that this evening. This all started when trying to confirm which wires were which for the pump but I'm pretty sure those are established now. Which of those codes do you think will remain but aren't important? Like the evap stuff maybe?

Find the wiring diagram and conform you have continuity from the pump end to wherever it ties back to. You really can't replace wiring diagrams with asking on a forum.

 

[Leo Zugner]

yeah that’s kind of how all this started. I have a good ground now for the pump but the power wire is only getting .4v.

 

[Gtstorey]

.4 volts is just stray voltage and really is probably really 0 volts.

 

[Leo Zugner]

I guess I’m not sure how to determine why I don’t have power to that wire. That’s the mystery.

 

[Gtstorey]

You have to work your way along the chain from one end. That is why you need the wiring diagram. You have to figure out why it is broken. Although in this case the ECM (or maybe the BCM, can't remember what controls the relay with the wiring diagram) may not be telling it to turn on since you have several throttle codes. Throttle codes are bad. If they happen when the car is running it will go to reduced power mode. But it might not let the car start if it isn't running, this would need to be checked in the service manual. The fuel pump circuit code might do it also.

Check continuity, not voltage, from the fuel pump end back to the next connection point up the chain. If continuity checks out for the correct wires, go ahead and connect the fuel pump. Then see what happens. But you have list that will have to be worked through before the car is going to start and run correctly.

You need to spend the money on an all-data subscription or through ac-delco TDS system. Maybe the charm site is a replacement, but I haven't used it. But you can't work on modern automotive electrical without a service manual.

 

[Leo Zugner]

all-data seems to be down. DF doesn't supply any wiring diagrams? Seems like that would be helpful.

AH, I was hoping for another hurdle...

 

[Gtstorey]

All data diy sees to work for me but I don't have a subscription to click all of the way through. I have a hard copy of the service manual for my donor.

Do It Yourself Automotive Repair Information | ALLDATA DIY

 

[Gtstorey]

There is a hard copy available for the 2005 on ebay but not cheap.

2005 Cobalt Service Manual in Manuals & Literature for sale | eBay

 

[Matt3458]

I got my wiring diagrams from https://mcdowellpubliclibrary.org/chilton-auto-repair/
Navigation isn't the greatest but it's free

 

[Leo Zugner]

cool. thank you. I'll check it out.