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2001 4.7 starts up runs perfect then shuts down after 5 seconds

23K views 31 replies 8 participants last post by  brandonppr 
#1 ·
I just got done fixing the bad head. It ran before but badly because of a lifter issue. I fixed that. Now I fire it up and it runs perfecty smooth and then just shuts down after 5 seconds or so.
 
#2 ·
Is it starved for fuel? Can you put a fuel pressure gauge on it? After it dies, does it immediately start or is it hard to start back up? Any codes?
Kevin
 
#3 ·
It will start back up without a problem then does exact same thing.
I can still hear the fuel pump running when it dies.
I still have the security light flashing, but before I took it down it would run if I held the gas and it ran poorly, now it runs great but dies.

I still need to check for codes. I am going to go get a scanner and see if it has any.
 
#5 ·
these are my guesses trying to help or promote the correct answer. LOL :huh:blkjak

p1388 - The code refers to the auto shut down relay. Pull the relay out and switch it with the a/c relay. If it starts and runs, replace the relay.

p1491 - check the # 39 fuse.

P1685 - The Sentry Key Immobilizer Module (SKIM) is part of the security system and kills the vehicle when a wrong key is used. There may be a problem with your key or the chip reader in the ignition switch. This code will also be set if someone actually tried to steal the vehicle. Using a spare key maybe that's it.
 
#17 ·
OK another $100 dollars and still no real answer.

I changed pcms and it did nothing different.

I took it to the dealer and luckily I got to talk to the tech about it.

The tech showed me where his computer would not comunicate with the skim module. He told me that it may need a new module but it does not need a PCM. He said that it could also be faulty wiring with something to do with the skim module.

So the tech told me he was taking the paperwork to the in because I told him not to go any further.

I go in and talk to the advisor. She says to wait because the service manager is finalizing the paperwork.

The advisor comes back and tells me that they believe it needs a new PCM and they can replace the PCM but that may not fix it.

So now I got it back home. If I had not spoke with the tech I would be in the same boat I was in before bringing it in and would have gotten the wrong diag from the advisor.

What now?

Should I try to figure out if the skim module is bad?
Is there a way to bypass it?
The tech told me that the pcm runs the car as long as its getting the signal from the skim module that it wants to see. Could I just give the pcm this signal myself and cut the wire to the skim module.
Where can I find a PCM pinout for it?
 
#18 · (Edited)
This is a worthwhile project. SKIM bypass for those with the grey keys.
I guess we need to put a scope on a skim module when the correct and incorrect keys are installed. It might be simple enough.
or If I could find a 15 year old from that crappy neighborhood I lived in 10 years ago... I bet he would know

I wonder what the same pin in the PCM on a non-skim car does.
Kevin
 
#23 ·
I agree with you. I only meant to say that someone out there has reverse engineered it. I am still interested to know how to bypass it.
I just did a google search for Sentry Key bypass and it seems that a lot of the remote starters bypass it fine. If you had the install instructions for those, you might be able to get by without it. It looks like you can buy a bypass module too but it is not clear to me without more reading if it needs to be working in order to initialize the bypass or if it is a true bypass.
Kevin
 
#25 ·
I just found this and after reading this I think it may be hopeless to bypass it:

The primary components of the system are:


Sentry Key Immobilizer Module (SKIM) Sentry Key (ignition key w/ a transponder molded into the head)
Indicator light
Body Control Module (BCM)
Powertrain Control Module (PCM)
When the ignition switch is turned on, the SKIM interrogates the ignition key. If the ignition key is Valid or Invalid, the SKIM sends a PCI Bus message to the PCM indicating ignition key status. Upon receiving this message the PCM will terminate engine operation, or allow the engine to continue to operate.

The SKIM is mounted to the steering column with the molded, integral antenna mounted on the ignition housing. The indicator light, is located in the message center.

The SKIS includes keys from the factory which are pre-programmed. Each SKIM will recognize a maximum of eight Sentry Keys. If the customer would like to own additional keys other than those provided with the vehicle, they can be purchased from any authorized dealer. These keys must be programmed to the SKIM on the vehicle in order for the system to recognize them as valid keys. This can be done by the dealer with a DRB III scan tool or by a customer if this feature is available in their market and they have two (2) valid keys already available to them. Refer to the Service Procedures portion of this system for additional details.

The SKIS performs a self-test each time the ignition switch is turned to the ON position and will store Diagnostic Trouble Codes (DTC's) if a system malfunction is detected. The SKIS can be diagnosed and any stored DTC's can be retrieved using a DRB III scan tool as described in the appropriate Body Diagnostic Procedures manual.

SENTRY KEY IMMOBILIZER SYSTEM (SKIS) OPERATION
When ignition power is supplied to the SKIM, the SKIM performs an internal self-test. After the self- test is completed, the SKIM energizes the antenna (this activates the transponder chip) and sends a challenge to the transponder chip. The transponder chip responds to the challenge by generating an encrypted response message using the following:

Secret Key - This is an electronically stored value (identification number) that is unique to each SKIS. The secret key is stored in the SKIM, PCM and all ignition key transponders.

Challenge - This is a random number that is generated by the SKIM at each ignition key cycle.

The secret key and challenge are the two variables used in the algorithm that produces the encrypted response message. The transponder uses the crypto algorithm to receive, decode and respond to the message sent by the SKIM. After responding to the coded message, the transponder sends a transponder I.D. message to the SKIM. The SKIM compares the transponder I.D. to the available valid key codes in the SKIM memory (8 key maximum at any one time). After validating the key ignition the SKIM sends a PCI Bus message called a Seed Request to the engine controller then waits for a PCM response. If the PCM does not respond, the SKIM will send the seed request again. After three failed attempts the SKIM will stop sending the seed request and store a trouble code. If the PCM sends a seed response, the SKIM sends a valid/invalid key message to the PCM. This is an encrypted message that is generated using the following:

VIN - Vehicle Identification Number

Seed - This is a random number that is generated by the PCM at each ignition key cycle.

The VIN and seed are the two variables used in the rolling code algorithm that encrypts the valid/invalid key message. The PCM uses the rolling code algorithm to receive, decode and respond to the valid/invalid key message sent by the SKIM. After sending the valid/invalid key message the SKIM waits 3.5 seconds for a PCM status message from the PCM. If the PCM does not respond with a valid key message to the SKIM, a fault is detected and a trouble code is stored.

The SKIS incorporates a VTSS LED located on the instrument panel upper cover. The LED receives switched ignition voltage and is hardwired to the body control module. The LED is actuated when the SKIM sends a PCI Bus message to the body controller requesting the LED on. The body controller then provides the ground for the LED. The SKIM will request VTSS LED operation for the following:


bulb checks at ignition on
to alert the vehicle operator to a SKIS malfunction
customer key programming mode
For all faults except transponder faults and VTSS LED remains on steady. In the event of a transponder fault the LED flashes at a rate of 1 Hz (once per second) . If a fault is present the LED will remain on or flashing for the complete ignition cycle. If a fault is stored in SKIM memory which prevents the system from operating properly, the PCM will allow the engine to start and run (for 2 seconds) up to six times. After the sixth attempt, the PCM disables the starter relay until the fault is corrected.
 
#27 ·
Thats the problem. It was a repo and I know nothing about it. It had a stuck valve when I got it, but it did run even though it was like crap. It did have a security light on when it was running though. it was flashing and doing a few wierd things.
I found a ground off when I put the new head on.
I got it back together and now I am having the skim problem.
I tried unhooking the ground and see if it would at least run, but it made no difference.

If I do take it back to the dealer I'm going elsewhere because the advisor lied to me.
 
#28 ·
The only way around the SKIM that I know of is to replace the pcm and the bcm together with non SKIM ones but before you do this you have to make sure the SKIM module is disconnected. If the SKIM is left connected then as soon as you turn the key on the pcm and bcm both look and recognize the SKIM and log it into their respective memory. Once it's in there you can't get it out. I've never personally done this but it should work.

Common problem not being able to talk to the SKIM module, it usually ends up just being the SKIM itself. Get a new one and have it installed and programmed, any shop that has access to a DRB III can do it...any halfway decent shop will have a DRB III. Of course you will need to get teh PIN from the dealer but that's no big deal adn you shouldn't even be charged for it.
 
#30 · (Edited)
OK I got the new module and installed it. Also got the Pin from the dealer when I got the skim module.

Now I can't find anyone besides the dealer to program it.:huh:
Anyone know a place near franklin tn?

edit: finally found a place. Taking it in the the morning $75 to program skim module and key.
 
#32 ·
They fixed it. It was not the skim module. They could not connect either. I told them to go ahead and figure out what it was. They found 3 wires cut behind the cluster. They said it was strange.
This was a repo and someone may have cut it on purpose. I bought it from the loan company. I think this thing is cursed because its still got problems.
 
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