Letters: Dealer installs ‘co-pilot’ to aid diagnosis

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Q: My husband reads your column all the time and is hopeful that you may give us some insight on a problem with our son’s 2011 Dodge Challenger.

In the past couple of months my son’s 2011 Dodge Challenger has been stalling when he takes off from a stop after driving for at least a half hour to work or back home from work. The engine usually stalls after he is stopped and he removes his foot from the brake pedal. After the engine stalls, it will start up right away and then my son is able to continue with his commute.

It has been back to the dealership but since the “service engine soon” light hasn’t come on, they haven’t been able to diagnose the problem. The dealer installed a “co-pilot” device on the car in an attempt to record data from the computer when the engine stalls. My son has been instructed to push the button on the “co-pilot” right when the engine stalls.

So far, the engine has stalled twice with this device installed. Hopefully it will register the problem. Do you have any insight as to what this problem may be, or have you heard of this problem from other Challenger owners?

Penny, email

A: That “co-pilot” device should provide the technician with some insight as to what might be causing the stalling. This device is designed to record data from various computers before, during, and after an event. Pushing the button places a marker on the recording so the technician will be able to see what happened to various data indicators before, during, and after the engine stalls.

As for what might be the cause, since the engine starts up right away, we can rule out usual suspects like the crankshaft position sensor, fuel pump, or problems with the wiring. I think it could be an issue with the programming in the PCM (Powertrain Control Module). There might be an update (known as a “flash”) available or Chrysler could be working on one. I haven’t heard from other Challenger owners on this dilemma, but that doesn’t always mean your son’s Challenger is the only one afflicted with this problem.

Hopefully when your son takes his Challenger back to the dealer they’ll be able to get to the source of the problem once they download the file from the “co-pilot” and analyze the data.

Q: I have a 2004 GMC Canyon pick-up truck with the five-cylinder engine. It has 70k miles on it and recently it has started to give me trouble when filling the fuel tank. The nozzle keeps shutting off before the tank is full. It takes a long time to fill the tank. Can you tell me what could be causing this problem?

John, email

A: The vent line from the fuel tank could be restricted or plugged, or there could be a problem with the vent solenoid. This solenoid is normally open so fresh air is allowed to flow into the Evaporative Emission system’s charcoal canister. The charcoal canister stores fuel vapors until they are drawn out by the engine during certain operating conditions. The PCM (Powertrain Control Module) energizes the vent solenoid to close it during testing of the Evaporative Emissions system. A vent solenoid that’s stuck closed could be the cause of your concern. But before replacing this solenoid, have a technician make sure that the vent line is clear and unrestricted.

Questions for Ira Siegel? Call the Auto Advisor Hotline at (708) 633-6839 or e-mail ira.siegel.is@gmail.com. Siegel is an automotive instructor and an automotive service excellence-certified master auto technician.