Restore Your Van’s Performance and Reliability
Is your 2003 Chevrolet Express 1500 Van acting up? Experiencing frustrating issues like intermittent stalling, rough idling, poor fuel economy, or a persistent Check Engine Light? These are classic signs that the heart of your vehicle’s electronics—the Powertrain Control Module (PCM)—is failing. Don’t let a faulty computer keep your reliable workhorse off the road. This is the direct, dependable solution you need to get your van running like new again, without the exorbitant costs and scheduling headaches of a dealership visit.
We take the guesswork and complexity out of the repair. This module, compatible with part number 89017733, arrives at your door fully programmed with the latest official GM software updates. All we need is your vehicle’s VIN at checkout. This critical step ensures that the PCM is a perfect match for your van’s specific configuration, making the installation process as simple as plug-and-play. This isn’t just a part; it’s a complete, ready-to-install fix that restores communication between your engine and transmission for optimal performance.
A Technician’s Notebook: The Intermittent No-Start Mystery
I remember a 2003 Savana van—nearly identical to the Express—that came into my bay with a maddening problem. The owner, a plumber, said it would randomly refuse to start. No crank, no click, nothing. Then, an hour later, it would fire right up. He had already replaced the battery and starter. After checking all the primary circuits, my scan tool revealed a stored DTC P0601 (Internal Control Module Memory Check Sum Error). This code is a definitive sign of internal PCM failure. The module’s processor was failing intermittently, cutting communication and preventing the starter relay from engaging. We installed a VIN-programmed PCM, and the van has started reliably ever since. This is a common failure I’ve seen on these work vans, and a correctly programmed module is the only proper fix.
Is Your GM Vehicle Showing These Symptoms?
- ✔ Unexplained Check Engine Light illumination
- ✔ Engine stalling or shutting off while driving
- ✔ Failure to start or intermittent starting problems
- ✔ Harsh or erratic automatic transmission shifting
- ✔ Noticeable decrease in fuel efficiency
- ✔ Communication error codes, such as P0601, P0606, or U0100
- ✔ Failure to pass an emissions test
A Straightforward Guide to Installation
Installing your new 2003 Express 1500 PCM is a manageable job for a DIYer with basic tools. Follow these steps carefully for a successful replacement.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery and secure it away from the post to prevent any accidental electrical contact.
- Locate the PCM: On the 2003 Express Van, the PCM is located in the engine compartment on the driver’s side (LH), typically towards the rear of the compartment.
- Disconnect the Connectors: Carefully unclip and disconnect the wiring harness connectors from the old module. These connectors have locking tabs that may need to be released with a small flathead screwdriver. Be gentle to avoid damaging the pins or clips.
- Remove the Old Module: Unbolt the old PCM from its mounting bracket. Keep the mounting hardware, as you will need it to install the new unit.
- Install the New PCM: Mount your new, pre-programmed PCM onto the bracket and secure it with the original hardware.
- Reconnect Everything: Firmly plug the wiring harness connectors into the new module. You should hear or feel a click as they lock into place. Reconnect the negative battery terminal.
- Final Steps: Your vehicle may need to complete a security relearn procedure, which typically involves turning the key to the ‘On’ position for 10-15 minutes. In most cases, the vehicle is now ready to start.
Verified Vehicle Compatibility
This module is a direct-fit replacement for a wide range of GM vehicles. Please verify your model and engine options below. This part is a replacement for service numbers: 12581565, 12570557, 12576106, 89017733, and more.
- 2003 Chevrolet Express 1500/2500/3500 Van (LH rear engine compartment)
- 2003 GMC Savana 1500/2500/3500 Van (LH rear engine compartment)
- 2003 Chevrolet Silverado 2500/3500 Pickup (8.1L Gas, LH front under battery)
- 2003 GMC Sierra 2500/3500 Pickup (8.1L Gas, LH front under battery)
- 2003 Chevrolet Avalanche 2500 (LH front under battery)
- 2003 Chevrolet Suburban 2500 (8.1L, LH front under battery)
- 2003 GMC Yukon XL 2500 (8.1L, LH front under battery)
- 2003 Chevrolet S10 / GMC Sonoma (4.3L, RH front engine compartment)
- 2003 Chevrolet Blazer / GMC Jimmy (RH front engine compartment)
- 2003 Chevrolet Astro / GMC Safari (LH front by battery)
- 2004 Cadillac CTS (Base, ID 12581565, RH engine compartment)
- 2004 Chevrolet Corvette (ID 12581565, RH engine compartment)
Frequently Asked Questions
Do I need to do anything after installing this PCM?
Do I need to do anything after installing this PCM?
No! Because we program the module to your specific VIN before shipping, it is ready for installation right out of the box. In some cases, a simple security relearn procedure (turning the key on for 10-15 minutes) is all that’s needed. No trip to the dealer is required.
Is this the same as an ECM or Engine Computer?
Yes. The terms Powertrain Control Module (PCM), Engine Control Module (ECM), and Engine Computer are often used interchangeably. For this 2003 Express 1500 PCM, it controls both engine and transmission functions.
How do I provide my VIN?
After you complete your purchase, you will need to send us your 17-digit Vehicle Identification Number (VIN). We will provide clear instructions on how to do this. We cannot program and ship your module without it.
Will this fix my transmission shifting problems?
If the shifting problems are caused by a faulty module, then yes. The PCM controls shift points and line pressure in the transmission. A failing PCM is a very common cause of harsh or erratic shifting in these GM vans.