OK Vinay
maybe this article may help clear things up.
1. "PASS KEY" The KEY had a coded resistor pellet embedded in it.
2. "PASS LOCK" The coding device(s) are in the LOCK
[ Quote from the article below----PASSlock doesn't require a coded resistor pellet in the key.]
The wires that connect the LOCK to the MODULE MUST be within the resistance limits in the article otherwise the system will go into theft/tamper mode.
So yours could be a bad connection giving a high resistance on these wires or a failure of Hall effect switch/resistor/diode contained in the lock --i.e. New Lock needed
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Anti-Theft Systems
PASS-key theft-deterrent system
To reduce the risk of car theft, many GM vehicles feature the patented PASS-key theft-deterrent system. Each ignition key has a black, coded resistor pellet embedded in the key. When you put the key in the ignition and turn it, the system reads the resistor. If the system doesn't get the correct code, the car won't start.
PASSlock theft-deterrent system
Similar to PASS-key is the PASSlock theft-deterrent system. With PASSlock, when you turn the ignition lock, a sensor in the lock sends a resistance code to the on-board computer. If the code isn't correct, the computer shuts off the fuel to the vehicle's engine. PASSlock doesn't require a coded resistor pellet in the key.
Both systems have been incredibly successful in limiting theft of GM vehicles. In fact in 1984, before this system was developed, the National Highway Traffic Safety Administration reported that 13 of the top 20 stolen cars were GM models. By 1995, no GM vehicles were on the top 20 list.
http://www.gm.com/company/gmability/safety/security/theft_deterrence/ PASSLOCK DEFININTION FROM GM
Dear Roy:
The vehicle is a �99, Chevy K2500 4x4, VIN 1GCGK23R9XFO69260, with a 5.7L engine and four-speed automatic transmission. It has 68,000 miles.
About two years ago, I installed a remote starter. Everything was fine for the first few months, and then I started to have trouble starting the truck. The security (Passlock) light would flash but would not let the truck start. I would have to wait with the ignition on for 20 minutes before it would start again.
I decided to take it to a Chevy dealer. The dealer told me that remote starters would not work on this truck, and they advised me to remove it, which I had them do. Things were OK again for few couple months, and then it started to happen again. This time they said that they believed that the Passlock system was the trouble.
They cut me new keys. They said that the aftermarket key that I was using was not exactly cut like the GM key. They also told me that the ignition switch has the (Passlock) system in it and did not like the aftermarket key. My keys do not have the chip in them; it�s in the switch.
Things were OK again � until it would not start again. This time they said that the fuel pump was bad and because the dash gauges were acting weird, that the sensor also could be bad. So after replacing the pump and sensor and about $700 later, it seemed to be working. HA!
Now while I�m driving, this happens about twice a week. I�ll be driving and the security light will flash twice, it will �beep beep beep� and the engine shuts off. At 60 mph in heavy traffic, it gets a little hairy. I have to shift to Neutral, wait for the rpms to drop, and then restart the engine. It doesn�t start the first time, but does on the second try. Then I shift back into Drive and keep going.
It also does not want to start in the morning. It can take as many as six attempts before starting. It doesn�t happen every morning, but occurs about three times a week.
I�ve been back to the dealer. They hooked the handheld computer to it and came up with a code for the Passlock. Now they think that it is the ignition switch. They said that they have never heard of the Passlock shutting off the engine after it was running.
It feels just like I�m running out of gas. Could the Passlock be telling the pump to shut off? I�m sorry for the length of this, but I needed to give as much detail as I could. Please help if you can.
Dennis Huffman, Supervisor
Huffman�s Garage, Westminster, MD
Dear Mr. Huffman,
When the security lamp flashes, the system has detected a problem. Did the dealer state what code they retrieved with the scan tool?
Nevertheless, here�s how this system works: The Passlock sensor contains two Hall-effect sensors, a resistor and a diode. When the key is inserted into the magnet and the lock cylinder is rotated, an analog voltage code is sent to the Passlock module. This is compared to the last learned voltage code. If the codes match, the Passlock module sends a Class 2 message to the PCM to enable the injectors.
The two wires that connect the Passlock sensor to the Passlock module are critical in that a 7-ohm variation on the ground wire (orange/ black) or a 100-ohm variation on the signal wire (yellow) will prevent the engine from starting.
Your problem appears to be an intermittent connection somewhere in the Passlock system. I would check for poor connections such as poor solder joints, crimps, corroded connectors and rubbed through insulation at the module and steering column as well.
When you installed the remote starter, did you tap into any of these wires? If you did, I would head there first.
Hope this helps
Alont
