This car has an intermittent no start condition with the security light flashing. Checked codes and found code B2960 stored. The code is for a valid but incorrect passkey signal. Now there are several different things that can cause this code but the most common is a failing passkey sensor which is part of the ignition tumbler kit. Some of the others are a faulty Ignition Switch, Body Control Computer and poor connections in the wiring harness. Because this problem is usually so intermittent there is not much real testing you can do that will result in a clear answer. I have found the only practical thing to do is to look at passkey voltage with a Tech 2 and gently wiggle the wiring some at the ignition switch and the BCM to see if there is any problem with the harness. Also look at passkey voltage while switching the key off and on. It should be about 5 volts when you initially switch the key on and then drop to a value higher than 0 and lower than 5 volts. Normally I see anywhere from .78 to 3.9 volts. If I see no other problems I always change the ignition tumbler kit and install a new ignition switch as well. If one is failing the other will not be far behind. I have seen plenty of these ignition switches fail without a passkey fault so I replace both as a rule.
With that out of the way this is the what you have to do to change the switch. Drop the tilt steering column to the full tilt down position. Remove both of the dash end caps and remove a screw from each end. Start pulling the trim panel from either end until the clips release. If it does not seem to want to release check for any extra screws that may be retaining the panel. If none are found pull harder but please be careful as panels can break.
After the trim panel is released you will have to disconnect the switches. The hazard switch needs the center tab depressed while you pull the harness connector from the switch.
The Traction control switch needs the center tab lifted slightly while the harness connector is pulled from the switch.
You will also need to remove the lower panels. There and a coulpe of retaining screws and a retaining pin or two. After all retainers are removed pull the cover towards the driver’s seat.
Disconnect the trunk release switch if present and now you will find a metal panel.
Remove the attaching screws and place aside.
Next you will need to remove the two 10mm headed screws that hold the switch assembly to the dash.
Next pull the switch down through the opening in the bottom of the dash.
With the key off release the locking tabs and pull the two main harnesses from the ignition switch. Make sure the key is off, it will save programming time.
Next turn the key on and depress the locking tab for the shifter interlock cable and pull the cable out of the switch.
Next depress the metal locking pin that hold the tumbler and sensor assembly into the ignition switch, rotate the key and pull the assembly out of the ignition switch.
Disconnect the sensor wiring harness by depressing the two side locking tabs and pull from the switch.
Install the new ignition switch and then install the new tumbler and sensor assembly.
I have another post for assembly of the tumbler kit. Please click here to see that post.
After the ignition switch and tumbler assembly are back together turn the key on and reinstall the shifter interlock cable. Then Make Sure The Key Is Off and Then Connect The Two Main Harness Connectors. Again this saves programming or relearn time. Now attempt to start the engine. Do Not be surprised if it does not start. Leave The Key ON and Wait about ten minutes or until the security light stops flashing. You may have to repeat this process up to four times in all before the system will relearn the new sensor value. The closer the new sensor value is to the original the quicker it will relearn. On some rare occasions you will have to use a Tech 2 and reprogramming software to teach the system the new value.
Overnight or even during the day my Impala backup lights turn on when I notice in the morning out the door and turns out that it seems that word on the battery what’s wrong
It sounds like the actual ignition switch (electrical portion) may be failing. I would recommend testing voltages at the ignition switch or relevant fuses. I have seen where pushing in firmly or rocking the lock cylinder & key when the condition is present may overcome it and lead to an easy diagnosis.
Sometimes it starts right away… And those days/times there’s no issues… When it has issues sometimes I hold the key in the start position for a good minute or so and it starts… When that happens the starter starts the car it starts right away but then has electrical type problems… After holding the key there and it starts then it sounds fine but the fuel gauge and temperature gauges take a few seconds to catch up it says security and sometimes the radio takes a few seconds or minutes to catch up. The thing that’s getting me is that some days particularly when it’s cooler out there’s no issues at all
From your description it sound like you may have several problems with your vehicle. Let’s try and go as far on one issue as possible before tackling the others. I need clarification on the no start condition. Does the engine fail to run or does the starter fail to function, while the key is held over for several seconds? How long is the key actually held in the crank position and what is going no during this time?
Thank you so much! We are at a loss… My car is a 2003 Chevy impala 3.4l… So on hot/humid days when I go to start the car it doesn’t start if I happen to get it to start its after holding the key in the start position for a while it starts but says security in the message box and takes a few seconds for the gas gauge temperature gauge and the radio to come on.. Sometimes while driving it it hesitates is kinda jumpy for lack of better terms… Then when I shut it down and take the key out it takes a good few seconds for the car to even turn off after key has been removed! We have checked the battery its 100%.. We changed the ignition module because someone said that was the problem but it isn’t… The door lock/trunk pop fuse keeps blowing with a day or so of changing it..
Thank you for taking time to hear my problems! Hope you can help!