Is Your 1997 GM Truck or Van Running Rough?
If you’re behind the wheel of a classic 1997 GM workhorse like an Express van, a Suburban, or a C/K pickup, you know they’re built to last. But when the central computerโthe Powertrain Control Module (PCM)โstarts to fail, it can cause some of the most frustrating and difficult-to-diagnose problems I’ve seen in my 20+ years in the shop. The symptoms can seem completely unrelated, leading you down expensive rabbit holes of replacing perfectly good sensors and parts.
A failing PCM in these specific 1997 models often presents as a vehicle that’s just plain unpredictable. One day it runs fine, the next it won’t start, or it shifts gears so hard it feels like you’ve been rear-ended. This isn’t just an annoyance; it’s a reliability issue that can leave you stranded.
A Technician’s Real-World Experience
“A customer’s 1997 Tahoe came in last month with a classic no-start condition. The owner had already replaced the fuel pump and the fuel pump relay, but it still wouldn’t fire. The check engine light wasn’t even coming on with the key. After checking the basics, we hooked up our scope to the fuel pump relay control circuit. We found the PCM wasn’t providing the ground signal to energize the relay. The root cause wasn’t the fuel system at all; the PCM’s internal driver circuit had failedโa common issue on these older modules after decades of heat cycles. A replacement PCM, correctly programmed, had it running in under an hour.”
Common Symptoms of a Failing 1997 GM PCM
Over the years, I’ve diagnosed hundreds of these specific PCMs. The failures almost always trace back to a handful of tell-tale signs. See if any of these sound familiar:
- โ No-Start or Intermittent Starting: The engine cranks but won’t fire up. This can be due to the PCM failing to control the fuel pump or ignition system.
- โ Harsh or Erratic Shifting: The transmission slams into gear, hesitates, or seems to be in the wrong gear for the speed.
- โ Check Engine Light (CEL) On or Off: You might have a constant CEL with various codes, or more concerningly, the light might not illuminate at all during the key-on bulb check.
- โ Poor Fuel Economy & Performance: A struggling PCM can’t properly manage the engine’s fuel and timing, leading to a noticeable drop in power and an increase in fuel consumption.
- โ Stalling for No Reason: The engine may stall at idle, at a stoplight, or even while driving.
- โ No Communication: A scan tool cannot connect to the PCM, making diagnosis impossible.
The Direct Solution: A VIN-Programmed PCM
The solution isn’t just any replacement module off a shelf. For these 1997 GM vehicles, the PCM must be correctly programmed with your vehicle’s specific Vehicle Identification Number (VIN) and the latest GM software calibrations. Without this step, the vehicle simply will not run correctly, if at all. This is where our service saves you significant time, money, and hassle.
We take all the guesswork out of the process. When you order this PCM, we will:
- โ Require Your VIN: After your purchase, simply provide us with your 17-digit VIN.
- โ Perform Professional Programming: Our technicians will flash the module with the correct, updated software directly from GM for your exact vehicle.
- โ Ship a Ready-to-Install Part: The PCM you receive is prepared for your vehicle. This eliminates the need for an expensive trip to a dealership or specialized shop for programming.
Installation & Important Notes
This PCM is typically located in the engine compartment on the driver’s side (LH), often near the battery or on the inner fender. Installation is straightforward for a DIYer with basic tools.
Note: After installing the new PCM, some vehicles may require a simple security relearn procedure (often called Passlock or Passkey) or a Crankshaft Variation (CASE) relearn. These procedures can usually be done without special tools and instructions are widely available online or in service manuals.
Guaranteed Fitment for Your 1997 GM Vehicle
This module, part number 16229684 (also compatible with 8162296840), is the correct Electronic Control Module for a wide range of gasoline-powered 1997 GM trucks, vans, and SUVs. Please verify your vehicle is on the list below:
Trucks:
- โ Chevrolet 1500 / 2500 / 3500 Pickup
- โ GMC 1500 / 2500 / 3500 Pickup
- โ Chevrolet S10 / GMC S15/Sonoma (4.3L V6)
- โ Isuzu Hombre (4.3L V6)
Vans:
- โ Chevrolet Express 1500 / 2500 / 3500 Van
- โ GMC Savana 1500 / 2500 / 3500 Van
- โ Chevrolet Astro Van
- โ GMC Safari Van
SUVs:
- โ Chevrolet Suburban 1500 / 2500
- โ Chevrolet Tahoe
- โ GMC Yukon
- โ Chevrolet Blazer S10 / GMC Jimmy S15 (4.3L V6)
- โ Oldsmobile Bravada (4.3L V6)