Went to start my car yesterday morning and not a peep from the starter despite a fully charged battery. Pulled codes and had:
P1631 H C
B2721 H C

Ok, fine. Grabbed the spare key - same result! No crank.
I'm a 1999, manual trans., 60k mi, w/#3 680 Ohm pellet and both keys were +/- less than 1% of that value.

Ok, fine. Spliced a 680 Ohm resistor into the white wires to bypass the pellet check assuming something was wrong with the lock cylinder.
Same result! No crank. This is getting serious. Time to stop guessing and do some actual diagnostics work.

Pulled the Anti Theft Relay (ATR) from passenger footwell and bench tested it. Works like a charm.

Tested red wire at ATR - has 12V unswitched.
Tested yellow wire at ATR - has 12V when key at start position!
Jumped Yellow/Black wire from ATR to ground and attempted to start - same result, nothing.
Tried jumping red to purple to bypass ATR and bump solenoid - nothing, not even a spark!

Battery is hot 12.5v at instrument cluster.
When ignition switched on bulb test etc happens.
If a door is open security blinks but goes out when I close the door.

Befuddled! Any ideas what to try next?

 

First off, thanks for the help!! No headers, just stock exhaust. No helper either. This is my only transportation and I'm stranded at home until I figure this out!

I was beginning to think it might be starter/solenoid too after I tried to bypass the TDR and didn't get peep out of the solenoid. I also checked the purple wire at the TDR and there are just a 50 milliohms which seems about right for a solenoid 2 feet away.

I crawled under the car and looked for loose wires or corrosion/melted insulation. Everything looks fine visually. The purple wire is sound and tightly attached. I rapped on the starter housing with a tack hammer, then tried to start it with the key. Nothing. I have a remote starter switch but there is so little room near the solenoid I couldn't attach the leads. I tried jumping the solenoid with a screwdriver like I used to do when I was a lazy kid. Got a spark but no click. Honestly, it wasn't much of a test and I don't recommend that approach. I'll have to jack everything up and remove the X-pipe to really get at the unit.

But before I do that there is the issue with those current codes I pulled from the DIC: B2721 and P1631. They still show current even though I bypassed the pellet check with an inline resistor.

I've had zero issues with the starter or the solenoid in the past. I figure if it were the solenoid I'd have had some symptoms before a total failure? Can the solenoid be replaced separately on a C5? I've only been able to find a starter/solenoid assembly listed.

Again, thank you for the help!

 

Did you jumper the Red and Purple wires at the TDR to make the starter try and work?

Both of your codes are Pass and Theft deterrent related.


Mr. Sam

 

04 Z-06 65,000 miles , it was time for a new Batt. and cables removed the old batt. and tray cleaned repainted under the Batt. tray , washed it out with soda replaced cables to starter now spins great ,will not start but back fires .. NO CODES . Water in the PCM plugs ..Cleaned all grounds ..

 

Sorry this was supposed be a new tread .. Disregard THIS GOING TO PUT IT IN A NEW TREAD SORRY ..

 

Our STARTER SOLENOIDS are well known FAILURE POINTS. The iron spindle inside STICKS and causes this issue. If you WHACK it with something and it begins to work normaly,,, THATS THE ISSUE!

You can whack it and them go and try to crank it... SOMETIMES, that works. Been there, done that, changed the solenoid! FIXED!

Good troubleshooting by the way!

Bill

 

OH and IF you don't correct 2721,, it never going to crank using the key..

Are you still getting the DTC??????????????

BC

 

Hi Bill! Those pesky codes are still showing current when I try to start it with the key even with my resistor bypass.

I dropped the X-pipe last night so I could get my remote start toy onto the back of the solenoid contacts. With 12v at the red cable I tried energizing the S-contact (purple wire terminal) and didn't hear a click or anything. I tried whacking the housing a few times with my tack hammer and still didn't get click. I then tried connecting the red cable to the main starter cable with my toy and at least I got the starter motor to spin! Meanwhile, the fellows at O'Reilly's Auto Parts found a replacement solenoid but I need a Torx E5 socket to R&R the solenoids. Man! I got every Torx tool there is but not an E5.

Anyway, what surprises me is that I could have both a bad solenoid AND an anti-theft issue at the same instant in time. My current approach is to just get the starter working properly and deal with the BCM problem later. The BCM looks shiny and new externally and I've never had an issue with it. I've had the car since new and not done any electrical mods either.

Thank you for your help!

 

Hi Dadaroo! Yes, I removed the TDR and jumped the red and purple wires with 12v confirmed at the red terminal. Got nothing, not even a spark when I installed the jumper.

One thing I haven't checked is the continuity between purple contact at the TDR and the purple wire at the starter s-terminal. If that wire got severed somehow.... I'll report back on the resistance after I check it.

Edit: Before reattaching the starter I checked the resistance of purple wire (circuit #6 for the purists) between the TDR connector and the S terminal on the solenoid and got 6 ohms. The manual says 2 ohms or less but I was using 3 jumpers to stretch my multimeter leads so it didn't surprise me it was a little on the high side. Nothing wrong with the wire.

Thanks for helping me!

 

Start at the battery cables/terminals. The proper battery cable to battery terminal is 11 ft/lbs. IF, you can move a battery cable on the battery by hand, its TOO LOSE!

The purple wire JUMPED to the red 60 AMP wire should INSTANTLY cause the starter to crank the engine.

Carefully examine the Plastic Bakelite connector on the back of the solenoid.

I bet ya its cracked/burnt/damaged and or the battery cable on the main terminal is loose/burnt corroded.

 

Bill, thanks for the ideas and the pictures!

I managed to find a Torx E5 socket to remove and replace the solenoid. I just knew I was barking up the wrong tree but since I'd bought the solenoid I figured I'd swap it just to see. After getting the new solenoid on, replacing the starter, and reinstalling the X-pipe, I jumped the red wire to the purple wire at the TDR. Bump went the starter! Now we're cooking. I got behind the wheel and checked for codes at the DIC. The B2721 code was just showing H, not HC as before! I can't explain why. But I turned the key and the motor started instantly.

So, the culprit was the solenoid. I replaced it with SSDR-124 by Wilson Electric. There is a guy on Ebay that currently sells them for $24.95 and free shipping by the way. The Delco Remy starter requires a rare narrow E5 Torx socket to remove the 3 screws holding the solenoid onto the starter motor. Once you have that socket it takes all of 2 minutes to swap the solenoids.

Looking at the old solenoid there is nothing that seems broken or scored. The plunger was moving freely and well lubricated, the plastic disk on the end of the plunger looked perfect, the coil just a few milliohms of resistance. All the wire connections were tight with just a small amount of surface corrosion. Once the wires were removed from the terminals there was shiny metal surfaces within. I can't explain why the solenoid didn't work.

Thank you everyone for helping me on this weird problem. I was confused and it REALLY helps having folks that have seen these problems before making suggestions. I still don't know why the DIC was throwing anti-theft codes. But bypassing the TDR (jumping red to purple) told me my starter was dead and the resounding consensus here was that I really should focus on that - and hope.

Edit: On second thought I guess if the solenoid coil developed a short that bypassed a lot of the turns, the coil would appear ok to a continuity check yet not induce enough magnetic field to retract the plunger. That's my best guess anyway. I still haven't a clue why the anti-theft codes popped up showing HC but I do recall somehow triggering the car alarm shortly after the no crank was discovered? I used the key on the driver side door to shut off the horn alarm.

 

Glad you resolved it.


Mr. Sam