Troublesome Airbag Light
Q: The battery went dead on my 1996 Ford Explorer without any warning. Since then, the airbag light won't go out. I unhooked the battery for an hour then hooked it back up to recycle it, but it still comes back on. Any ideas?
A: During normal operation, the airbag indicator will light up when the ignition is switched from "Off" to "Run", and then go out after about six seconds. If a fault exists, the indicator won't come on at all, will remain lit continuously, or will begin flashing after 30 seconds to indicate trouble codes stored in the system's memory. Accurately scanning and diagnosing the system requires the appropriate service information and the correct scan tool, in this case, a New Generation Star tester or equivalent. It may be coincidental that the indicator light came on after losing battery voltage. But it shouldn't be a "reboot" situation-there's a fault in the system that requires repair. I'd suggest getting it to a trained technician at a Ford service department. And keep in mind the dangers of accidental airbag deployment before attempting any repairs on your own.
My Ram Won't Shift
Q: I have a 1998 Dodge Dakota 2WD with an automatic transmission that won't upshift. It stays in first gear. Even under wide-open throttle the rpm will climb all the way to redline without shifting. I only have first gear and Reverse. Also, when I put the truck into Reverse from Park, there's a buzzing/whirring noise that lasts about two seconds and then goes away. But there are never grinding noises. The truck has roughly 55,000 miles and has been serviced twice so far using exclusively Mopar ATF+4 transmission fluid. I suspect the governor pressure sensor and/or solenoid might be the problem.
A: The governor valve allows the powertrain control module, after analyzing relevant data, to regulate the transmission's hydraulic pressures and efficiently control shifting. Proper diagnosis is going to require a road test, a scan tool, and a hydraulic pressure gauge. Top-three possible causes for a good first gear and Reverse, but no 1-2 or 2-3 upshift, are a governor-circuit electrical fault, a valve-body malfunction, or a damaged or burned kickdown servo or band. Your hunch on a governor pressure problem is indeed plausible, but I wouldn't invest any money prior to verification by a technician. Odds are in your favor, but the problem could be a more extensive internal breakdown that may require overhaul or replacement. Figuring it out should be straightforward for a transmission technician.
Searching for Servos
Q: In a previous column you answered a question regarding a cruise-control kit for a 2004 Jeep Wrangler. It stipulated you had to have a certain "servo connector" for it to work. Could you please tell me how to find out whether or not my Jeep has this connector?
A: Regardless of the engine, 2.4-liter four-cylinder or 4.0-liter inline-six, the cruise-control servo is mounted under the hood and on top of the left fenderwell. The cruise-control servo is basically a vacuum diaphragm that opens and closes the throttle by means of a cable. Search near the fenderwell and in front of the master cylinder for a black four-wire connector. It should have black, tan, light-green, and dark-blue wires coming out the back, all with red stripes except for the black one. Keep in mind that unused connectors can be well hidden. You also can call a local Jeep service department, with your vehicle identification number handy, and ask them to look up the build date of your particular Wrangler. If it falls between 3/20/03 and 3/12/04, the wiring harness needed for installation of the Mopar speed-control system was not installed at the factory. There also may be a Jeep technician you can speak with at the service department, experienced in the system's installation, who might be of further help.