bgray

I got in my 02 coupe today and tried to start it and it wouldn't crank. Everything did as it should, but nothing. The relays made their sounds, accessories shut off, etc. I got under the car with the ignition on and powered up the starter by jumping the solenoid to the battery and the car started and ran. I load tested the battery and it is good as well as still on a trickle charger. I pulled all the fuses applicable and swapped the relays. I read some other posts and tried the key idea. The other two keys did the trick. Car started and ran no issues. Tried four times. Both checked out. Tried the first key and had to wait the 3 minutes for the BCM to reset. Thought, GREAT, the forum does it again! I had to push my luck and try with the good keys half an hour later. Now, the car cranks but won't stay running with the good keys. My car is moodier than my wife! As I was writing this, I went out and the two good keys started the car and kept it running. The bad key is still bad. Being intermittent, this is going to be one hell of a repair bill. Any ideas before I let GM clean out my wallet?

BlackZ06

I kinda doubt it is the keys .... you have an intermittent problem, and I think the swapping of keys is just confusing it further ...

One reason I doubt it's the keys, if the BCM "thought" that a bad key was in the ignition, you should not have been able to start and run the car by jumping the starter to the battery. The PCM would not have received the "fuel password" from the BCM if the BCM thought it was a bad key.

I'd see if there are any DTC posted, that may help you to pinpoint the problem. Go here for instructions if you haven't displayed the DTC data before ...


https://www.corvetteforum.com/techti...D=26&TopicID=1

Let's take it from there ... good luck,

IYPopeye

I'm betting its a corroded battery terminal. I know you looked, but did you take a good look under the red plastic on the positive terminal? Corrosion can be shiny and make the elec system intermittent. Remove red plastic & soak cable end in a baking soda solution, wire brush it and coat with vicks vaporub or some other petroleum jelly.

bgray

Gets more interesting every time. The DTC codes now are:
BCM B2587 H (column lock/unlock drive (A))
BCM B2592 H (column lock/unlock drive (B))
A6-SCM U1255 H (serial data line malfunction)
After I read them I tried to start it with a good key and got the "remove the key and wait 10 sec". Did that and we are back to the no cranking. I appreciate the help.

bgray

What do I have to lose. I will go after those terminals right now.

BlackZ06

The easy one first, delete the U1255, it is meaningless in this context. Then, I'd delete the two Bxxxx codes, and see if any of them come back. These are generally set when the dreaded "COLUMN LOCK" problem appears, but since they are H codes, hopefully they are old news.

After you delete all the codes, try a start and run sequence again, then check for codes.

The good news is that if you have no codes it is probably something simple like the wiring to the starter motor, the bad news is that without codes it is one of those "hunt all over" for the problem kinds of issues.

Let us know what you find,

bgray

Those codes may be H codes but they are relatively new. I recently cleared all the codes. Now, I went out and cleaned both cables and the battery terminals with a brush. Then reconnected them using di-electric tune-up grease. (smells better than vics) Now, all three keys are working and the car starts and runs. I am praying that your simple fix was the way to go!! I checked again for codes and there are none. I will keep trying as the way my car is acting, it may be too soon to declare victory. I owe all you guys a beer when you are in the ATL next. Whether or not we fix it, I appreciate it.

bgray

Nope, not that easy. Just tried to take it to run to the store and nothing again. Turn the key all the way and no reaction. Also, there are no codes. At least we ruled out the key idea. It started at one point on all three keys. Any more ideas?

dgrant3830

Is the security light on or flashing?

BlackZ06

Next thing I'd check is the wiring at the starter motor. You want to undo BOTH battery cables from the battery before you mess with the starter as the POSITIVE cable from the battery is hot unless you disconnect it at the battery. There have been a number of cases where the wires to the starter have come lose, and even where the heat generatted by the bad connection has damaged the terminals. Before removing any wires, make a diagram of not only which wires go where, but also the approximate angle they are mounted at. Try and remount them at approximately the same positions/angles.

Best of luck, keep us posted.

cedge

had a buddy's car do the same, start but not stay running. put new battery in everything ok. good luck.

bgray

Security light only flashes the normal way. When you get into the car until the door is closed. The light doesn't flash a bit until during the starting process or after you pull out the key.

bgray

Not a bad idea, but did his ever just do nothing when the key was turned? That is what my car is back to. Turn the key and there is no reaction other than the buzz of the relays.

dgrant3830

I suggest you PM Bill Curlee and see if he has any thoughts to offer.

IYPopeye

Yep - we were on the right track here, and I will bump that beer to a six-pac on this: You wire-brushed the cable-end, but did not take the red rubber protector off & did not soak the end of the positive cable in a thick solution of baking soda, then wire-brush & re-assemble. So now you have a shiny coat of corrosion on the end of the cable that looks like metal, but it is not. Try again, but be sure all corrosion is gone this time. Check it with an ice-pick. I prefer Miller Genuine or Corona.

IYPopeye

One more thing - Be sure to remove that battery charger before you try to restart!! All but the best chargers put out a noisy square-wave instead of true DC, and the square wave's leading edge starts with a spike that can blow the diodes in your alternator.

bgray

I just pulled the battery terminals and soaked them as IYPopeye suggested. While they were soaking I pulled the two chassis ground connectors, brushed them and reconnected them with di-electric grease. I pulled the battery terminals out of the soak, brushed them and greased them as well. With all reconnected, the car still does nothing when it is supposed to be cranking. Any more ideas??

IYPopeye

Amazing. I went thru a nearly identical set of symptoms with my '02 coupe, tried relay swaps etc just like you did. Strange & changing messages came to the instrument panel readout. All the low power devices (door lights, instrument panel, etc) worked fine, but no start & no headlights. All that adds up to high power not getting from the battery to the elect system; poor connection. I took out the battery & battery case to inspect the cabling to the starter, which was ok on mine. The positive cable was the culprit, which I discovered by poking an ice-pick thru the very tough & shiny corrosion at the battery connection. Must be a little different on your C5, but this still seems like the ballpark. With the battery out of the car, carefully run jumper cables to the starter & frame. Leave original + cable connected to starter to be sure relays etc. are powered thru branching wires. Will need 3/8 x16 bolts to attach cables to this model battery. Replace battery cable if this works. Six pack waiting for you in Los Angeles, if Chevy winds up with your money.

Slick Rick

Try a new battery. Not a recharged one........

BlackZ06

See my post #10 above, check the cables at the starter.