Yeah, I've had numerous codes and not always the same ones. They only start flying when I hold the key in the START position to keep the car running. Otherwise, the only code thrown is HVAC B0338 for the inside air temp. sensor. It also says "Low Oil Level"

When I do hold the key past ON to keep it running, I still get "Low Oil Level" but also get "Service Active Handling" and "Service Engine Soon" (or however they are labeled). I also get a slew of codes, usually like 1 PCM, 1 BCM, 5 HVAC, 2 Radio, 1 SCM, 1 LDCM, 1 RDCM. I usually just ignore them because I know I'm really just doing something screwy with the car - forcing the fuel pump to run by holding it between ON-START.

 

this may sound trivial, however, make sure your battery terminals are torqued to 11 ft-lbs and your ground points on the car to 106 in-lbs. can you even believe there are torque specs for this sh*%.

 

I've had those battery terminals off and on 10 times this week and have probably tightened them tighter each time, out of anger more than anything else, haha.

The grounds are also plenty tight. In fact, I broke the ground stud off behind the driver's headlight. Had to jumper it to another screw. We checked all my grounds and stuff with a volt-meter and all checked out.

Tomorrow or Sunday I'm gonna have a buddy's extra PCM to swap in there. I should have at least looked at my PCM and connections by now but I just haven't. I didn't have my low profile jack to get under the car to jack it up and get the wheel off. If the PCM swap and associated wire checking down there doesn't pan out, it's going off to the stealership. At least I have a friend that will be working on it there.

Another question I have, the ground on the passenger's side of the block (at the very top) was the one that was initially not even finger tight for me when this problem started. I keep reading that TWO eyelets should be grounded there. I only have ONE which appears to be going down to the starter.

What the heck else should be there and would that not being there have an effect in this case? I don't know how it could have come off, if it's an eyelet. The bolt wasn't out of the hole, just loose.

 

i do remember having 2 on mine but i dont remember what they were for. as an update the ignition fix from bill curlee did solve my problems. are you sure that you can swap a pcm from 1 car to another? i thought they were vin coded.

 

Well, we messed around with the car some more today. Thanks to Bill Curlee for a lot of things to try over the phone today. The list of things we've tried now stands here:

1. Cleaned and voltmeter checked all grounds.
2. Reconditioned and tested the ignition switch 4 times.
3. Checked the fuel pump and ignition relays by swapping with another.
4. Checked the fuel pump, PCM, and other fuses by swapping with others and with a voltmeter.
5. Cleaned my key and tried to clean inside the lock cylinder with alcohol.
6. Swapped my PCM with another that was flashed with my tune with EFI Live.
7. Checked the star connectors under the passenger kick panel.

The PCM swap seemed to not work right, the car would crank but not fire. Probably the hand-shaking deal with the PCM and BCM. It was worth a shot anyway.

Some things we've noticed:
1. The fuel pump does NOT come on when the key is in the ON/RUN position.
2. 99% of the time it will say, "low oil level".
3. One time today, for the first time ever, I saw "Remove Key, Wait 10 Seconds".
4. The column does lock/unlock when you insert and remove the key like it should.
5. The security light doesn't do anything strange.
6. I can hear clicking under the passenger floor-board.
7. The passenger floor board is dry and shows no indication of water entry or corrosion.
8. I can hear a click back by the fuel pump when the key is turned to ON/RUN.
9. Voltage at the fuel pump and PCM fuses in the ON/RUN position was the same as the battery at one point (about 12V) but later it always read 0V. Never did figure that one out.
10. We datalogged with HP Tuners and noticed the settings where you can do things like turn the fan on (which worked) and turn the fuel pump on (which did NOT work).
11. If the key is held past ON/RUN, the car will stay running but will give messages like "Service Active Handling", "Service Vehicle Soon". It will also shine the ABS light and traction control light and will throw random codes such as this set I got today (I had cleared them right before starting the engine):
PCM - P1571H
TCS - C1277H
SDM - U1040H
HVAC - B0338CH (inside temp. sensor is unplugged)

I have seen a set of codes with as many as 12 different ones at once. It's very random. All out of ideas from here. I have a buddy that lives about 100 miles away that works for GM, the car is getting towed to him tomorrow for diagnosis and repair. I'm very anxious to find out what the deal is and will report back as I receive details.

 

I still think your missing the ON/ RUN voltage to one or more of the modules. Crank seems to be working just fine. Recommend that you examine the PCM ON/RUN (as the manual calls it "HOT ON & START" ) voltages from the fuse numbers that we discussed.

Recommend that you check the voltages to the PCM and other critical modules when the ingition is in the HOT ON & START position.

The PCM tells the fuel punp to run. Send me your e-mail address and I will se if I can send you the schematic that pretains to the problem.

Some times I can copy them and sometimes I cant! DAMN DVD

Bill

 

PM sent, Bill.

We did check the voltage at the PCM, fuel pump, INJ1 & INJ2 fuses. In the RUN position, the PCM and fuel pump showed 12V one time but always showed 0V the other 15 times we tried it after that. The INJ1 & INJ2 fuses always showed 0V.

We did so many things but I'm 99% sure we watched the voltage on at least the fuel pump and PCM fuses and saw no change in voltage at START.

I don't know why the hell we saw 12V only one time in RUN but I guess it's the same reason we also heard the fuel pump prime at RUN only once.

Doing all these starts has made me have to charge my battery about 5 times now. Most of this testing was done with it connected to my other car and with it showing 13 volts, so I assume it's safe to rule out a weak battery since I was leveraging a stronger one?

 

did you ever get to the bottom of this?

 

My bet,,,its the switch or connections at the plug.

BC

 

It's all over now! G105 was the culprit! I thought the diagram meant that the braided ground strap was G105, not under the block! After more and more research, it all made sense and sure enough here was my G105!



I knew it would be faulty after I figured out where to look but never expected the bolt to be GONE! Replaced it, used lock tite, car starts right up with no more codes or anything! So glad to have this 10 day ordeal over with!

 

nice job. i knew you'd get. sounds like we're both back on the road just in time for summer. and you know i'm checking that G105 next time i'm under my car.

 

Heck yeah, might as well while you're under there.

 

Hopefully those springs we had left over from you ignition switch aren't very important.

 

Weight reduction my boy, weight reduction.. haha. Yeah, one of the four times we reconditioned and tested my switch, we had the lock cylinder apart and springs went everywhere. It works just fine and all but we never did figure out where two of the 4-5 smaller springs were supposed to go!

 

Note to self:

Self: inspect, clean, reinspect, and reinstall G105.

 

Where is this G105. I can not tell by looking at the close up picture.

 

Thanks for the ground info.

 

Thanks for posting when you were having problems. I was having the same problems as you and after I performed bill's iginition steps I found your thread. Sure enough it was g105 for me too!