Why does security ligh flash while driving

I know that you do not want to hear this, but when you have an electrical issue as this it takes some major tracing the wiring circuit and I have found stay away from a shade tree type mechanic go to a electrical shop. Good Luck Mike

You can't do anything ,unless you have diagnostic computer . Check codes , program key etc.... Call a mobile lock smith or have towed to the dealer .

I would ask the dealer to do this but here is what I show to get the light reset. This is courtesy of expert Techmecho

If the tech 2 device is indicating the code for 4wd module then it has to be replaced.Get the module and its connections checked before going to replace the module.If the module connections are getting short or loose then getting the connections repaired solves the problem.But most probably when it shows module problem,the module has to be replaced.The actual testing procedure is as follows:--- If you have an ODBII code reader, you can check if there are any codes stored in the ECU. There is also a diagnostics mode you can go into for transfer case issues:

1. Warm up the engine. Turn it off.
2. Turn the ignition switch on and off at least twice, then turn the ignition switch to off.
3. Shift into park.
4. Turn the 4WD selector to Auto.
5. Turn the ignition switch to on. Do not start engine.
6. Is the 4WD warning lamp on? Continue if no.
7. Shift into reverse.
8. Turn the 4WD selector to 2WD, Auto, 2WD.
9. Shift into drive.
10. Turn the 4WD selector to 4H, Auto, 4H.
11. Shift into neutral.
12. Turn the 4WD selector to Auto.
13. Shift into park.
14. The 4WD indicator light will come on for 2.5 seconds, then go out. It will then flash a series of times to represent a one or two digit code, with half-second delays within a number and 1 second delay between numbers. e.g. to represent the code 23, it will flash twice with 0.5 seconds between flashes, wait a second, then flash three times with 0.5 seconds between them.Get it rechecked again by disconnecting the 4wd module and reconnecting again,. --------------------Thank you.

Passlock
The passlock system is a vehicle theft deterrent system which deters drive-away vehicle theft by disabling engine operation if the ignition lock cylinder is not rotated with the proper mechanically cut key.
The passlock system is made up of an ignition switch assembly, passlock sensor, body control module (BCM), instrument panel cluster (IPC), and a powertrain control module (PCM).
The ignition switch contains a magnet mounted on the lock cylinder and a passlock sensor assembly which consists of security hall effect sensor, tamper hall effect sensor, and output resistors. A drill proof metal shield is also staked over the sensor housing.
The passlock sensor mounted to the ignition switch assembly is located inside the upper right side of the steering column. The passlock sensor contains two hall effect sensors: a tamper hall effect sensor and a security hall effect sensor. The tamper hall effect sensor is mounted on top of the security hall effect sensor. Should someone attempt to defeat the system by use of magnetic experimentation, the tamper hall effect sensor will activate first.
The BCM has the passlock controller integrated into it which controls the majority of the security systems logic. The BCM reads the data from the passlock sensor continuously. If the data is correct and has been received by the BCM within a specified time, the BCM will send a coded password to the PCM. The PCM will then allow the fuel injectors to operate.
The coded password for the security system is sent from the body control module to the PCM via the class 2 data link. If the password is correct and received within the specified time, the PCM will allow the fuel injectors to operate.
The IPC contains the security telltale. The security telltale has three modes of operation, OFF, FLASHING, and ON.
SECURITY TELLTALE will be off if:
?€¢
Ignition is in the OFF position

?€¢
Ignition is in the RUN, START, or ACC position and security system diagnostics have all PASSED

SECURITY TELLTALE will be on if:
?€¢
The BCM is performing a bulb check at vehicle start

?€¢
Security system diagnostics have not yet completed at vehicle start

?€¢
A security system diagnostic trouble code (DTC) is set in the BCM or PCM

SECURITY TELLTALE will be flashing if:
?€¢
The tamper hall effect sensor has been triggered

?€¢
Incorrect passlock sensor data to BCM for more than 5 seconds during vehicle start

?€¢
No passlock sensor data to the BCM for more than 5 seconds during vehicle start

?€¢
Incorrect password from the BCM to the PCM after 5 seconds during vehicle start

You can get the code by switching the key to run, off, run, off, run. The last time you switch it to run leave it on. The check engine light will flash the code. just count the flashes. you can find more info on this on the internet along with what the codes mean. As for the problem the codes will probably point to the cam or crank position sensor failing.

This is a common issue with this car, it's most likely a faulty ignition switch. It could be another electrical issue but I doubt it. Have it's codes checked and look for a security fault. The ignition in this model of car is horrible, just Google around and you'll see. It can be replaced at home but you will have to re-learn the ignition cylinder security, takes about 10-15 minutes for the procedure. The instructions on how to replace and re-learn are on the net, if you take it to a mechanic I wouldn't see them charging longer than a hour to fix it, it could probably be done in less than 30 minutes. I don't recommend using a used ignition switch from a junkyard, it is hit or miss on a good working one. If the security light isn't on or no codes were set I would do more diagnostics before making a purchase.

First --- spark plugs seldom fail to fire & cause misfires,
unless they are badly worn & you also have other issues,
such as ignition coil or module problems or vacuum leaks,
to name two.
Also codes are not needed to diagnose any vehicle problem.
To say they can't diagnose a cylinder misfire or a torque converter lock-up solenoid or codes, means you went to the wrong shop or they misunderstood your intentions to spend any money, to actually perform the necessary testing or diagnostic procedures

Sometimes the anti theft security system that came on these cars start to fail and the car can literally turn of the starter and/or injectors. Next time this happens, check to see if there is a light on the dash that says SECURITY. This would be a dead give away of the problem. This link describes security symptoms, and possible DO IT YOURSELF solutions. http://vatspasslockpasskeysecurityhelp.yolasite.com/

SOUND LIKE THE THEFT SECURITY PROBLEMS. MOST OF THE TIME.THE IGNITION KEYS OR IGNITION SWITCH KEY LOCK CYLINDER WORN WHERE THE BCM AND PCM DONT RECOGNIZE KEY OR SWITCH SIGNAL.SO THE BCM AND PCM WILL GO IN THEFT SECURITY MODE.THE DEALERSHIP WILL HAVE TO FIX.BECAUSE IF THE KEYS , IGNITION SWITCH AND LOCK CYLINDER AND BCM HAS TO REPLACED.THEY WILL HAVE TO BE REPROGRAM USING DIAGNOSTIC EQUIPMENT. NOT A HOME FIX.YOU WILL NEED TO GET FIX SOON AS POSSIBLE.BECAUSE FAULTY SECURITY THEFT CODE WILL SHUT DOWN VECHICLE FUEL SYSTEM WHILE DRIVING OR IT WILL GET TO A POINT WHERE CAR WONT START NO MORE.THIS FIX WILL COST ABOUT $600.00.

http://img178.imageshack.us/img178/3331/obdikx3.jpg

The above link is to a diagram of your ALDL connector, all you need is a paper clip, straighten out the paper clip and insert one end into the diagnostic test pin and one in the system ground pin (terminals A & B).

Then put the key in the ignition and turn it to the on position but DO NOT start the engine. You will then see the check engine light flash. It will initially start by flashing once, then a pause and then flash twice and it will repeat this three times. That flash sequence indicates 12, which just means the system is operating. Its the flash sequences after that that will give you the code if any are stored.

For instance if it flashes twice, then pauses, then flashes four times, thats code 24. So any flash sequence you get after the initial 12 (flash once, pause, flash twice) you need write those down. Below is a list of diagnostic codes to tell you what the codes mean.

Code 12
1 flash, pause, 2 flashes
Diagnostic: This Code will flash whenever the diagnostic terminal is grounded with the ignition switch turned on and the engine is not running.

Code 13
1 flash, pause 3 flashes
Oxygen sensor voltage stays between 0.35 and 0.55 volts for 30 seconds when the TPS signal was above 0.55 volts. The engine had been running for at least 40 seconds with an engine temperature above 110° F.

Code 14
1 flash, pause, 4 flashes
Coolant temperature sensor signal indicates a temperature of over 284° F for 4 seconds after the engine had been running for at least 10 secondsCoolant Sensor Circuit (high temperature) If the engine is experiencing overheating problems, have those fixed before continuing. Check all wiring and connectors associated with the coolant temperature sensor. Replace the Coolant temperature sensor.

Code 15
1 flash, pause, 5 flashes
Coolant Sensor Circuit (low temperature) Coolant temperature sensor signal indicates a temperature colder than -36° F for at least 4 seconds after the engine had been running for 2 seconds. See above, then check wiring connections at the ECM

Code 16
1 flash, pause, 6 flashes
Charging system voltage was either below 9 volts or above 17 volts for 10 seconds. System High Voltage If the voltage is above 17.1 volts for more than 2 seconds, the Service Engine Soon light will illuminate. Have the charging system checked.

Code 17
1 flash, pause, 7 flashes
PCM did not detect any spark reference pulses within 240 fuel control reference pulses (80 crank revolutions) while engine was running below 1200 RPM. Spark Reference Circuit.

Code 21
2 flashes, pause, 1 flash
Throttle Position Sensor, TPS voltage was above 0.8 volts for 5 seconds when engine was running and air flow was less than 15 gm/sec, or the TPS voltage was over 4.8 volts at any time.

Code 22
2 flashes, pause, 2 flashes
Throttle Position Sensor check TPS adjustment. Replace the TPS sensor. TPS voltage was under 0.2 volts for 4 seconds when the ignition was on. Check for a sticking, or mis-adjusted throttle position sensor.

Code 23
2 flashes, pause, 3 flashes
Inlet air temperature sensor signal showed an air temperature of -29° F for 4 seconds. Manifold Air Temperature. Check the MAT sensor, wiring, and connectors for a possible open circuit. replace the MAT sensor.

Code 24
2 flashes, pause, 4 flashes
Vehicle speed sensor signal showed less than 3 MPH for 2 seconds when engine speed was greater than 3000 RPM and transmission has not been in park or neutral for more than 4 seconds. Or vehicle speed goes from above 18 MPH to 0 in less than 2 seconds without applying brake. This code can only appear when the vehicle is in motion, if it appears when the car is not in motion, ignore it. Check ECM connections, any other problems should be diagnosed by a qualified mechanic.

Code 25
2 flashes, pause, 5 flashes
Inlet air temperature sensor signal showed an air temperature of over 218° F for 5 seconds when vehicle speed was greater than 35 MPH. Check the voltage between the MAT sensor and the ECM. voltage should be above 4 volts.

Code 26
2 flashes, pause, 6 flashes
Quad-Driver sense voltage shows a low voltage when battery voltage should be present, or if the sense voltage shows battery voltage when a low voltage should be present for at least 5 seconds when the engine was running. Have the car checked by a dealer.

Code 27
2 flashes, pause, 7 flashes
2nd gear switch was closed or grounded for 10 seconds when vehicle was in 4th gear, or 2nd or 4th gear switch was open when engine was first started. Gear switch Diagnosis Have the car checked by a dealer.

Code 28
2 flashes, pause, 8 flashes
3rd gear switch was closed or grounded for 10 seconds when vehicle was in 4th gear, or 3rd or 4th gear switch was open when engine was first started.

Code 29
2 flashes, pause, 9 flashes
4th gear switch was closed or grounded for 10 seconds when vehicle was in 4th gear, or 4th gear switch was open when engine was first started.

Code 31
3 flashes, pause, 1 flash
PRNDL indicates a gear other than park or neutral for 13 seconds for 3 consecutive startups when ignition was on, engine was off and vehicle speed was 0. Or the PRNDL status indicators (A, B, C, P) showed an incorrect combination of Lo and Hi for more than 10 seconds.
Check all connectors, and for a faulty switch.

Code 32
3 flashes, pause 2 flashes
EGR System Check vacuum hoses and connections for leaks and restrictions. Replace the EGR solenoid or valve.

Code 33
3 flashes, pause, 3 flashes
MAF Sensor Have the mass air flow sensor replaced.

Code 34
3 flashes, pause, 4 flashes
There was no MAF signal for over 4 seconds while engine was running. Check for loose or damaged air duct, misadjusted minimum idle speed and cacuum leaks. Inspect the MAF sensor and the electrical connections.

Code 38
3 flashes, pause, 8 flashes
The Torque Converter Clutch portion of the brake switch was open and caused the TCC to be inoperative, adjust OR replace switch.

Code 39
3 flashes, pause, 9 flashes
Torque Converter Clutch Check ECM connections, check for faulty Torque Conver Clutch solenoid.

Code 41
3 flashes, pause, 1 flash
Cam sensor signal was not received by PCM for the last 5 seconds while engine was running. Check for faulty connections, or a faulty cam sensor. Maybe also indicate a problem with the vehicle's timing chain.

Code 42
4 flashes, pause, 2 flashes
The Electronic Spark Timing (EST) signal did not change when the ECM applied bypass voltage to the ignition module. Check for faulty connections, or a faulty ignition module.

Code 43
4 flashes, pause, 3 flashes
Knock sensor signal was either above 3.5 volts or below 1.5 volts for at least 20 seconds. Check for a faulty knock sensor, or Mem-Cal.

Code 44
4 flashes, pause, 4 flashes
Oxygen sensor voltage was under 0.25 volts for up to 4 1/2 minutes of closed loop operation, lean exhaust. Check the ECM wiring connections. Check for vacuum leaks at the hoses and intake manifold gasket.

Code 45
4 flashes, pause, 5 flashes
Oxygen sensor voltage was over 0.75 volts for 2 minutes in closed loop operation with a throttle angle between 0.6 and 1.9 volts. Rich exhaust. Check the evaporative charcoal canister and its components for the presence of fuel.

Code 46
4 flashes, pause, 6 flashes
Power Steering pressure switch Check for faulty connections, or a faulty switch.

Code 48
4 flashes, pause 8 flashes
Misfire Diagnosis. Check the ignition and fuel systems.

Code 51
5 flashes, pause, 1 flash
Prom or Mem-Cal Make sure the MEM-Cal or prom is properly installed in the ECM. Replace Mem-Cal or prom.

Code 52
5 flashes, pause, 2 flashes
Cal-Pak Check the Cal-Pak to insure properation. replace the Cal-Pak.


Code 54
5 flashes, pause, 4 flashes
EGR #2 solenoid was out of range for 6 of 8 tests. 55 EGR #3 solenoid was out of range for 3 of 5 tests.

Code 55
5 flashes, pause, 5 flashes
ECM Check for faulty connections. Replace the ECM.

Code 56
5 flashes, pause, 6 flashes
Quad-driver voltage was incorrect for 5 seconds on the circuit connected to QDM "B".

Code 57
5 flashes, pause, 7 flashes
Boost control solenoid did not open bypass valve causing engine torque to be too high.

Code 63
6 flashes, pause, 3 flashes
EGR flow was incorrect. EGR solenoid did not work properly. Have vehicle serviced by a dealer.

Code 64
6 flashes, pause, 4 flashes
Same as Code 63 EGR flow was incorrect. EGR solenoid did not work properly.

Code 65
6 flashes, pause, 5 flashes
Same as Code 63.