iwannaHHR

My wife called me as she was leaving work a couple days ago. When she got in the HHR she told me that she turned the switch 3 or 4 times and nothing happened. The radio A/C fan lights and everything is on and working fine but the engine will not turn over. She tried one more time and it started up like nothing was wrong. I took it to the dealership and they called back and told me they think it's the key itself. Since I took the car in I had my key and they want me to bring it back with both keys.

HipHotRod

Not with a GM car but I remember my Marauder had a chip in the keyblank for that PATS system. I had dropped the key and damaged the chip. Perhaps the same is happening to your wife's key?

iwannaHHR

I don't think there is a chip in the HHR key.

shaginwgn

There is a chip in the "key head." That is the reason they want all the keys for it because if you have to reprogram one, you have to reprogram all of them with the tech II scanner

an08HHR

When you see a GM key with a small + in a circle just below the part you grab, it has a chip within the black plastic covering.

HipHotRod

I thought so, its part of the anti theft ( joke ) components. As I mentioned, Ford's had a major problem with them. The chip was "added" to the blank and was easily jarred loose.

ChevyMgr

Or it will say PK3 (passkey III). It works from a transponder in the head of the key (the part you hold). It works as follows.

When an ignition key is inserted into the ignition lock cylinder and the ignition is switched ON, the transponder embedded in the head of the key is energized by the exciter coils surrounding the ignition lock cylinder. The energized transponder transmits a signal that contains its unique value, which is received by the TDM (Theft Deterrent Module). The TDM then compares this value to the learned key code stored in memory. If the value is correct, the TDM sends the challenge to the transponder. Both the transponder and the TDM perform a calculation on the challenge. The TDM then performs one of the following functions:

• If both the transponder value and the calculation to the challenge are correct, the TDM will send the start enable message to the ECM via the serial data circuit.

• If either the transponders unique value or the calculation to the challenge is incorrect, the TDM will send the start disable message to the ECM via the serial data circuit.

• If the TDM is unable to measure the ignition key transponder value for 1 second due to a damaged exciter, the TDM will send the start disable message to the ECM via the serial data circuit.

In other words it won't start.

ChevyMgr

Only the first key requires the tech II, after that up to 9 keys can be programmed. Programming is accomplished by starting the vehicle with the master key, turn it off, pull the key out and then put the new key in and start it. Same procedure is followed to do the remaining keys.

iwannaHHR

I didn't know that. It makes since now, thanks guys.