Restore Peak Performance to Your GM Vehicle
If you’re dealing with frustrating engine problems in your 2003 Chevy Express 2500 Van—like a persistent check engine light, poor fuel economy, or a dreaded no-start condition—a failing Powertrain Control Module (PCM) is often the culprit. As the central computer for your engine and transmission, its health is non-negotiable. This replacement PCM, part number 89017733, is the reliable, straightforward solution to get your vehicle running smoothly again. We take the guesswork and extra cost out of the repair by programming the module specifically to your vehicle’s VIN with the latest GM factory software updates before it even ships.
Case Study: A Tricky Diagnosis
I remember a 2003 Silverado 2500 with the 8.1L V8 that came into my shop on a tow truck. The owner said it would run fine for a week, then suddenly die at a stoplight and refuse to restart for an hour. There were no consistent trouble codes, just a random collection of communication loss errors (U-codes) and an occasional P0601 (Internal Control Module Memory Check Sum Error). After verifying the power and ground circuits to the PCM were solid, we knew the issue was internal to the module itself. Heat soak was causing an internal failure. Swapping in a pre-programmed PCM like this one solved the problem permanently. The owner was back on the road the same day without a single issue since.
Is Your GM Truck or Van Showing These Signs?
A failing PCM can cause a wide range of confusing symptoms. Over my 20+ years in the bay, these are the most common indicators I’ve seen that point directly to a faulty engine computer. If your vehicle is experiencing any of the following, it’s time to consider a replacement.
- ✔ Persistent Check Engine Light (CEL)
- ✔ Stalling, rough idling, or misfiring
- ✔ Vehicle won’t start or is difficult to start
- ✔ Poor or erratic automatic transmission shifting
- ✔ Decreased fuel efficiency
- ✔ Failure to pass emissions testing
- ✔ Diagnostic Trouble Codes (DTCs) such as P0601, P0606, or U0100
A Straightforward Guide to Installation
Replacing the 2003 Express 2500 Van PCM is a job most DIYers can handle with basic tools. Our pre-programming service eliminates the need for expensive scan tools or a trip to the dealership. Follow these general steps for a successful installation.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery and wait at least 10 minutes to ensure the system is fully discharged.
- Locate the PCM: On most GM vans and trucks of this era, the PCM is located in the engine compartment. On Express/Savana vans, it’s typically on the driver’s side rear of the engine compartment. On pickups and SUVs, it’s often under the battery tray on the driver’s side.
- Disconnect the Harnesses: Carefully release the locking tabs on the electrical connectors and pull them straight out from the module. Avoid pulling on the wires themselves. There may be two or more large connectors.
- Remove the Old Module: Unbolt the PCM from its mounting bracket. Keep the hardware, as you may need to reuse it.
- Install the New PCM: Mount your new, pre-programmed PCM onto the bracket and securely re-fasten the bolts.
- Reconnect Everything: Firmly plug the electrical harnesses back into the new module until they click into place. Reconnect your vehicle’s negative battery terminal.
- Final Step: In some cases, a security relearn procedure may be necessary, which typically involves turning the key to the ‘ON’ position for 10-15 minutes. Your vehicle’s service manual will have the specific steps if required.
Verified Vehicle Compatibility
This module is a direct-fit replacement for a wide range of GM vehicles. Please verify your vehicle is on this list and that the service number on your original part matches one of the numbers provided. This 2003 Express 2500 Van PCM is engineered to restore factory function.
- ASTRO 03: Electronic Control Module; (LH front by battery)
- AVALANCHE 2500 03: Electronic Control Module; (LH front under battery)
- BLAZER S10/JIMMY S15 03: Electronic Control Module; (RH front engine compartment)
- CTS 04: Electronic Control Module; (RH engine compartment), Base, ID 12581565
- CORVETTE 04: Electronic Control Module; (RH engine compartment), ID 12581565
- EXPRESS/SAVANA 1500 VAN 03: Electronic Control Module; (LH rear engine compartment)
- EXPRESS/SAVANA 2500 VAN 03: Electronic Control Module; (LH rear engine compartment)
- EXPRESS/SAVANA 3500 VAN 03: Electronic Control Module; (LH rear engine compartment)
- S10/S15/SONOMA 03: Electronic Control Module; (RH front engine compartment), 4.3L
- SAFARI (GMC) 03: Electronic Control Module; (LH front by battery)
- SIERRA/SILVERADO 1500 PICKUP 03: Electronic Control Module; (LH front under battery), w/4.3L
- SIERRA/SILVERADO 2500 PICKUP 03: Electronic Control Module; (LH front under battery), gasoline, 8.1L
- SIERRA/SILVERADO 3500 PICKUP 03: Electronic Control Module; (LH front under battery), gasoline, 8.1L
- SUBURBAN 2500 03: Electronic Control Module; (LH front under battery), 8.1L
- YUKON XL 2500 03: Electronic Control Module; (LH front under battery), 8.1L
This part is a direct replacement for service numbers: 12581565, 8125815650, 12570557, 12570558, 12576106, 12576869, 12578127, 88864822, 89017733.