Odometer all zeros / Won't start
 

Hi everyone, I'm new here. I drive a 2001 Saturn SC2, with Manual Transmission. It's roughly about 170,000 miles.

Here's the problem I'm running into.

I drove it over to my mother's house the other week and as I was leaving, it didn't start. I then observed that the odometer and trip meter had both reset to 000000.
The engine will turn over but won't stay cranked up. I tried to give it some gas while starting and there was no effect.
We hooked up a reader after this and it wouldn't even connect to the computer and so I thought that was my answer to this problem.
Apparently I was wrong. I replaced the computer with a used one and, although we can now connect with the reader (it says 0 problems), the car will still not start and the odometer / trip meter still say 000000. My brother in-law is a relatively seasoned auto mechanic and he's never seen anything like this.

Here's a few things we tried to see what would happen.

We ran a volt meter over every fuse we could get our hands on (there were some weird readouts but after fussing over it they mostly turned up normal.)
We removed fuses and singled out which ones were affecting the instrument cluster and verified that they weren't burned up. PCM I and PCM B in the fuse box located under the hood.
We can hear the fuel pump kicking on, so we're confident that it's working.
We disconnected and reconnected the battery a few times.
(I'm sure we did more but I can't think right now)

Here's a few side-notes.

My battery is junk, I've had to jump it pretty regularly lately. I'll replace it as soon as I can but all of these tests were conducted with a jump box connected to the battery.
A few months ago, my brake light and check engine light came on simultaneously. They went off here and there but eventually stopped and now are on all the time.

This is my last resort and I'm really hoping that someone can help shed some light on what we're looking at here.

Thanks in advance!

I'll need help from others on the forum, but here's my incomplete two cents with some questions.

The digital odometer and the "idiot" lights and SES light are controlled by the Body Control Module (BCM) on the 3rd gen S cars (99-02).
Usually, when the BCM goes bad, the dash lights up like a Christmas tree and the mileage goes wonky, to 678,906 miles.
That's not to say it cant be bad.

The start then stall behavior sounds very much like the security system kicking in.
What state is the security light/symbol
1) before inserting key and cranking
2) while cranking and momentarily running
3) after it dies

Your mileage is stored in the BCM.
The security system is incorporated into the BCM.
The ignition cylinder must send the "password" that the BCM is expecting to receive.
If the cylinder doesn't send the password the car will start and stall.
If the BCM doesn't correctly interpret the password, the car will start and stall.
If the BCM correctly interprets the password but for whatever reason, the BCM was expecting something different.
IIf the BCM correctly interprets the password and it matches what the BCM has stored, the BCM SHOULD signal the PCM that this crank is not a security breach and the car can run
HOWEVER, if the BCM never sends the OK message to the PCM, the car will start and stall.

You indicated your battery is wasted and you had been living off jump starts before this occurred.
There is a possibility that your alternator, trying hard to charge a battery that can't hold one, has given up the ghost.
If the voltage regulator inside the alternator went down with the ship, you have a potentially lethal situation as far as the car's electronics are concerned.
Hooking up a jump creates a current and voltage spike. How large? POSSIBLY large enough to damage delicate electronics like the PCM and BCM, which usually get power fed right from the battery. It HAS happened to many, with all makes of vehicles.

I'm thinking the BCM got damaged somewhere along the way OR you need to perform a PASSLOCK security reset (procedure is all over the saturn forums). Follow the directions EXACTLY as written.

As for the SES and brake light, they may be signs of a failing BCM or they may be real.

The code scanner you use has to be able to read P, B,, U, and X codes to properly scan ALL the vehicle's trouble code storage areas. P codes are emission, B codes are body codes including ABS and BCM, U are Chassis codes, and I can never remember what the hell X codes are.

Step 1: Put in a functioning known good battery
Step 1.5 Turn key to run and read with scanner capable as described above. Post codes here.
Step 2: Try to start car and note security light status as asked above
Step 3 will likely be PASSLOCK reset, so I suppose you can do that too. Can't hurt and may restore vehicle to running condition. However, once the BCM starts to fail, the security system will activate randomly forcing you to do the passlock reset and sometimes even that won't work.

If you get the vehicle running, take to autozone or similar and have a full load test pwerformed on your vehicle. It's free and should flag a dead or compromised alternator

Please keep us updated

I'll be doing all of this, what an amazing response. It will likely be a few days before I can accomplish all of this, (car is still at mother's house and I'm not)
I'll be getting a new battery tomorrow, hopefully.

Additionally, as far as the security system goes, it has been going off when the battery retains some charge.. even when the doors are unlocked and we've been in and out of the car.

Like Derf said first is a known good battery, next it probobly has a bad BCM. See how it behaves with a good battery first.

Once you install the new battery, check for codes. Post them here and go from those. DO NOT start shot gunning parts hoping for a fix. You'll spend a ton of money and still have a car that won't run.

New battery has been installed and when we read for codes, none came up. I'm considering purchasing a Body Control Module but my price range only really includes Ebay as an option. Do you know if i'll be required to reprogram the BCM?

Step 1: Put in a functioning known good battery
DONE
Step 1.5 Turn key to run and read with scanner capable as described above. Post codes here.
DONE - NO CODES RETURNED
Step 2: Try to start car and note security light status as asked above
TRIED TO START - SMELLED FUEL - DID NOT TURN OVER - SECURITY LIGHT WAS ON CONSTANTLY
Step 3 will likely be PASSLOCK reset, so I suppose you can do that too. Can't hurt and may restore vehicle to running condition. However, once the BCM starts to fail, the security system will activate randomly forcing you to do the passlock reset and sometimes even that won't work.
PERFORMED PASSLOCK RESET - SECURITY LIGHT IS NOW OFF - SAME RESULT WHEN TRYING TO START.

We checked for spark after this and found that there is no spark from the plugs
previously it would turn over and run for a second or two, now it will not turn over at all.

Well, by turning off the security light, you have theoretically addressed the security system portion. Also, you at least know that in theory, the security system input portion of the BCM works and that the ignition cyl is not s fault security wise.

Everything you have done to date seems to indicate BCM.
The one part that does not fit is that when you check codes on a bad BCM with a scanner capable of reading B codes, you usually get 1245 B codes thrown, thus indicting the BCM.
Are you positive your scanner can read more than just P codes?

One last ditch effort.

I went back and read your initial post. You said you replaced the PCM.
.I'm thinking your original PCM seemed to be communicating w the PCM, but security was blocking the starting (my guess)

The only unknown introduced wih the current config is the replacement PCM.

Discnn the neg battery term, swap the original PCM back in, re perform the Passlock reset. This will allow the original PCM to sync with the new PASSLOCK password you just changed it to by doing the relearn.
If all goes well and the security light stays off at the end of the relearn, the vehicle should start. and run. The fact that the security light was able to be turned off at least seems to indicate that the passlock messages are getting to the PCM.



Please let us know. I have suggested everything I know regarding this situation.
I have tried to help you avoid the expense of a replacement BCM and reprogramming by dealer.
If this last ditch effort doesn't work, I think BCM is inded hosed.

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Unfortunately, I have already placed the original PCM back into the car.

Originally, we couldn't get a code to read at all, it just wouldn't connect... but that was a cheap reader with a phone app.

We read zero codes on both PCMs
but the original is back in and this is based upon the reading that we took the other day. I am not confident that the reader used by my relative is capable of reading all the codes... but my car should be throwing a pre-existing codes. Nothing.

The cheap Chinese made Bluetooth dongles are crap.

​​​​​​What brand of scanner is it?
As for displaying previous codes that have been resolved, you have to direct the scanner to read the historical codes. It will not display them by default. It would be annoying as hell if it did every time you tried to read codes.

So if the original PCM was in there for the Passlock reset, and security light is off, the only other thing I can think of is the CKP, Crankshaft position sensor. When this fails,. It kills injectors and spark. Check the connector and wiring carefully. It is possible that wiring or a poor connections at either end were disturbed and the signal is no longer reaching the PCM. Check the PCM pins for corrosion. Check the connectors as well for corrosion.

And of course measure the resistance across the CKP. It should be around 500 to 700 ohms, but don't quote me on the range. Usually they fail open.circuit. And only 3 times in 14 yrs modding this forum has the code for it been thrown, so don't expect to see it.