On the last Monday of January our driveway was a sheet of glass. The ice storm had come through overnight, every branch on the maple out front was coated, and the Silverado was wearing a quarter inch of ice like a shrink wrap. I spent fifteen minutes chipping my way into the driver's door, started the truck, let it warm up, and turned the knob to 4 High.
The little light on the dash blinked. And blinked. And kept blinking. The truck stayed in two-wheel drive.
On a 2014 Silverado, when you pick 4 High, two things happen. The transfer case behind the transmission sends power to the front driveshaft, and a small electric actuator on the front axle connects the front axle shaft so the front wheels actually get pushed. When everything has engaged, the light goes solid. When the light keeps blinking, the truck is telling you it asked for 4WD and didn't get confirmation.
I did what the owner's manual suggests. I rolled forward a few feet and back to let the gears line up, tried shifting it while moving slowly in a straight line, and turned the truck off and on. Still blinking. So I drove to work in two-wheel drive with a bag of sand in the bed over the rear axle, slow, with long gaps in front of me on US-36. A pickup with an empty bed and no weight over the rear wheels is not a great ice vehicle in two-wheel drive. I knew that already. I knew it better by the time I got to the terminal.
Why it waited until February
I called our shop that afternoon. They were buried. Every car in town with a dead battery after the cold snap the week before, plus fender benders from the ice. The service writer asked if the truck was otherwise driving normal. It was. He said if I could live without 4WD for a few weeks, they'd get me in on Friday, February 20, and that's what I did.
That was a judgment call, and I'll be honest about why I was comfortable with it. The ice melted off the main roads in about two days. My commute is 11 miles of mostly highway that gets plowed and treated. I can work from home on a bad weather day if I absolutely have to, since dispatch can be done from the kitchen table in a pinch. If my job had been out on gravel roads, I'd have pushed harder to get it in sooner.
In the meantime, I didn't keep trying to force it. If the system is half engaged, grinding on it can make things worse. I left the knob in 2 High and kept the sandbag in the bed.
The diagnosis and the bill
The shop scanned the truck and found codes for the front axle actuator circuit. They tested the wiring and connector first, which is the cheap thing to rule out, and the wiring was fine. They also checked that the transfer case was shifting, and it was. That left the actuator, which they said is a known weak point on trucks this age, especially after road salt and a hard freeze.
- Diagnosis, 0.5 hour at $132: $66
- Front axle actuator: $168
- Labor to replace, 1.0 hour at $132: $132
- Shop supplies: $8
- Sales tax on parts: $12
Total: $386. The shop's labor rate went up from $125 to $132 at the start of the year, which I noticed on the invoice and wrote down, because noticing that kind of thing is apparently who I am now.
The diagnostic half hour is the line people grumble about. I don't. Somebody had to rule out the wiring, the connector and the transfer case before hanging a part on it. If they had just thrown an actuator at it and it turned out to be a corroded plug, I'd be paying for a part I didn't need. Thirty minutes of somebody who knows what they're looking at is cheap insurance against that.
What I'd tell myself next November
Test the 4WD before the bad weather shows up. That's the lesson. I check tires, wipers, the battery and the antifreeze every October, but I'd never thought to just put the truck in 4 High on a dry day and make sure the light went solid. An actuator that's getting weak will often get slower first, and I might have caught it in the fall when the shop wasn't swamped.
So it's on the October checklist now, right between "test the van battery" and "find the ice scraper that Lainey borrowed." The truck has about 142,800 miles on it now, and every system on it is going to start asking for attention sooner or later. I'd rather it ask on a sunny day.
The light went solid on the first try in the shop parking lot. I put it back in 2 High and drove home in the sunshine on dry pavement, which is the kind of victory you get when you're 46 and own a truck.