Restore Peak Performance to Your GM Truck or SUV
Is your 2003 Trailblazer EXT or another compatible GM vehicle suffering from frustrating, hard-to-diagnose issues? A failing Powertrain Control Module (PCM) is often the culprit behind problems like erratic engine behavior, poor fuel economy, or even a no-start condition that leaves you stranded. This replacement PCM, part number 89017734, is the reliable, straightforward solution you need. We take the guesswork and hassle out of the repair by pre-programming the module to your vehicle’s specific VIN with the latest GM software updates. This ensures optimal performance and compatibility right out of the box.
From the Diagnostic Bay
I remember a 2005 Silverado 2500 that came into my shop with a ghost of a problem. The owner complained of intermittent stalling at red lights and occasional harsh shifting from first to second gear. We couldn’t replicate it consistently, and the only stored code was a generic communication error. After checking all the wiring harnesses and grounds—a common issue on these trucks—we focused on the PCM. We knew that heat cycles and vibrations can, over many years, cause internal fractures on the circuit board. Swapping in a VIN-programmed PCM like this one solved the problem instantly. The updated GM software also smoothed out the transmission logic, a bonus the customer immediately noticed. It’s a perfect example of how the right part, correctly prepared, can save hours of diagnostic headaches.
Common Signs of a Failing PCM
If you’re experiencing any of the following, your PCM could be at the end of its service life. I’ve seen these symptoms countless times in my 20+ years of experience. A faulty PCM can mimic many other component failures, so proper diagnosis is key.
- ✔ Check Engine Light is on with codes like P0601 (Internal Control Module Memory Check Sum Error) or P0606 (PCM Processor Fault).
- ✔ Vehicle refuses to start or has difficulty starting.
- ✔ Poor or erratic engine performance, including misfires or stalling.
- ✔ Decreased fuel efficiency for no apparent reason.
- ✔ Automatic transmission shifting problems (harsh shifts, getting stuck in gear).
- ✔ Communication errors with other vehicle modules (U-codes).
A Straightforward Guide to Installation
Replacing the PCM on most of these GM trucks and SUVs is a job a confident DIYer can handle. Because we program the module beforehand, you won’t need a trip to the dealer for expensive flashing procedures. Just follow these general steps:
- Safety First: Always disconnect the negative terminal from your vehicle’s battery and wait at least 15 minutes for the system to fully discharge.
- Locate the PCM: On most compatible vehicles like the Silverado, Tahoe, or Hummer H2, the PCM is located in the engine bay on the driver’s side, near the battery or air filter box. For the Trailblazer EXT or Envoy XL, it’s typically next to the air box.
- Disconnect the Connectors: Carefully release the locking levers on the electrical harness connectors and pull them straight out from the module. Avoid wiggling them side-to-side, as this can damage the pins.
- Remove the Old Module: Unbolt the PCM from its mounting bracket. Keep the hardware, as you may need it for the new installation.
- Install the New PCM: Mount your new, pre-programmed PCM and securely tighten the bolts. Re-connect the electrical harnesses, ensuring the locking levers click firmly into place.
- Reconnect the Battery: Reattach the negative battery terminal.
- Perform Security Relearn (If Needed): In many cases, you will need to perform a simple security relearn procedure. This typically involves turning the key to the ‘ON’ position for 10-15 minutes, then ‘OFF’, and repeating two more times. This allows the new PCM to sync with your vehicle’s anti-theft system. Consult your vehicle’s service information for the exact procedure.
Will This Fit My Vehicle?
This module is a direct replacement for service number 89017734 and is also compatible with 89017750, 12582605, 12589463, 12602802, and 28042802. Please verify your part number or use the compatibility list below. If you’re unsure, contact us with your VIN!
ESCALADE 04 Electronic Control Module; (LH front under battery), ID 12602802
ESCALADE EXT 04 Electronic Control Module; (LH front under battery), ID 12602802
HUMMER H2 04 Electronic Control Module; (LH front under battery), SUV
SIERRA 3500 PICKUP 03 Electronic Control Module; (LH front under battery), gasoline, 6.0L
TAHOE 04 Electronic Control Module; (LH front under battery), ID 12602802
YUKON XL 2500 04 Electronic Control Module; (LH front under battery), 6.0L, ID 12602802
ENVOY XL 03 Electronic Control Module; 5.3L (next to air box)
SUBURBAN 2500 03 Electronic Control Module; (LH front under battery), 6.0L
YUKON 04 Electronic Control Module; (LH front under battery), ID 12602802
YUKON XL 2500 05-06 Electronic Control Module; (LH front under battery), 6.0L
AVALANCHE 1500 04 Electronic Control Module; (LH front under battery), ID 12602802
SIERRA 1500 PICKUP 07 Electronic Control Module; classic style (creased door skin), (LH front under battery), w/o hybrid option; w/o 4.3L
SIERRA DENALI 05-06 Electronic Control Module; (LH front under battery)
SUBURBAN 2500 04 Electronic Control Module; (LH front under battery), 6.0L, ID 12602802
YUKON XL 1500 03 Electronic Control Module; (LH front under battery)
YUKON XL 1500 04 Electronic Control Module; (LH front under battery), ID 12602802
ESCALADE ESV 03 Electronic Control Module; (LH front under battery), PCM
ESCALADE ESV 04 Electronic Control Module; (LH front under battery), ID 12602802
HUMMER H2 07 Electronic Control Module; (LH front under battery), powertrain control
SIERRA 3500 PICKUP 05-06 Electronic Control Module; (LH front under battery), gasoline, 6.0L
SIERRA DENALI 03 Electronic Control Module; (LH front under battery)
SILVERADO 2500 PICKUP 05-06 Electronic Control Module; (LH front under battery), gasoline, 6.0L
SUBURBAN 1500 03 Electronic Control Module; (LH front under battery)
HUMMER H2 05-06 Electronic Control Module; (LH front under battery)
SIERRA 2500 PICKUP 04 Electronic Control Module; (LH front under battery), gasoline, 6.0L, ID 12602802
YUKON 03 Electronic Control Module; (LH front under battery)
ESCALADE 05-06 Electronic Control Module; (LH front under battery)
ESCALADE ESV 05-06 Electronic Control Module; (LH front under battery)
SIERRA 2500 PICKUP 05-06 Electronic Control Module; (LH front under battery), gasoline, 6.0L
AVALANCHE 1500 03 Electronic Control Module; (LH front under battery)
SILVERADO 2500 PICKUP 03 Electronic Control Module; (LH front under battery), gasoline, 6.0L
SILVERADO 1500 PICKUP 04 Electronic Control Module; (LH front under battery), w/o hybrid option; w/o 4.3L; ID 12602802
TAHOE 03 Electronic Control Module; (LH front under battery)
TAHOE 05-06 Electronic Control Module; (LH front under battery)
YUKON 05-06 Electronic Control Module; (LH front under battery)
SILVERADO 3500 PICKUP 04 Electronic Control Module; (LH front under battery), gasoline, 6.0L, ID 12602802
SILVERADO 2500 PICKUP 07 Electronic Control Module; classic style (creased door skin), (LH front under battery), gasoline, 6.0L
SILVERADO 3500 PICKUP 05-06 Electronic Control Module; (LH front under battery), gasoline, 6.0L
SUBURBAN 1500 04 Electronic Control Module; (LH front under battery), ID 12602802
ISUZU ASCENDER 03 Electronic Control Module; (LH engine), 5.3L
SIERRA 1500 PICKUP 03 Electronic Control Module; (LH front under battery), w/o 4.3L
SIERRA 1500 PICKUP 04 Electronic Control Module; (LH front under battery), w/o hybrid option; w/o 4.3L; ID 12602802
ESCALADE 03 Electronic Control Module; (LH front under battery), PCM
SSR 03 Electronic Control Module; (next to air box)
SIERRA 2500 PICKUP 03 Electronic Control Module; (LH front under battery), gasoline, 6.0L
SIERRA DENALI 07 Electronic Control Module; classic style (creased door skin), (LH front under battery)
SILVERADO 3500 PICKUP 03 Electronic Control Module; (LH front under battery), gasoline, 6.0L
SUBURBAN 1500 05-06 Electronic Control Module; (LH front under battery)
TRAILBLAZER EXT 03 Electronic Control Module; 5.3L (next to air box)
SILVERADO 1500 PICKUP 05-06 Electronic Control Module; (LH front under battery), w/o hybrid option; w/o 4.3L
SILVERADO 1500 PICKUP 07 Electronic Control Module; classic style (creased door skin), (LH front under battery), w/o hybrid option; w/o 4.3L
SILVERADO 3500 PICKUP 07 Electronic Control Module; classic style (creased door skin), (LH front under battery), gasoline, 6.0L
YUKON XL 1500 05-06 Electronic Control Module; (LH front under battery)
ESCALADE EXT 05-06 Electronic Control Module; (LH front under battery)
SIERRA 1500 PICKUP 05-06 Electronic Control Module; (LH front under battery), w/o hybrid option; w/o 4.3L
SUBURBAN 2500 05-06 Electronic Control Module; (LH front under battery), 6.0L
HUMMER H2 03 Electronic Control Module; (LH front under battery)
SIERRA 2500 PICKUP 07 Electronic Control Module; classic style (creased door skin), (LH front under battery), gasoline, 6.0L
SIERRA 3500 PICKUP 07 Electronic Control Module; classic style (creased door skin), (LH front under battery), gasoline, 6.0L
SIERRA DENALI 04 Electronic Control Module; (LH front under battery), ID 12602802
SILVERADO 1500 PICKUP 03 Electronic Control Module; (LH front under battery), w/o 4.3L
ESCALADE EXT 03 Electronic Control Module; (LH front under battery), PCM
SIERRA 3500 PICKUP 04 Electronic Control Module; (LH front under battery), gasoline, 6.0L, ID 12602802
SILVERADO 2500 PICKUP 04 Electronic Control Module; (LH front under battery), gasoline, 6.0L, ID 12602802
YUKON XL 2500 03 Electronic Control Module; (LH front under battery), 6.0L
Frequently Asked Questions
How do I provide my VIN after purchase?
After you complete your purchase, you will receive an email with instructions. Simply reply to that email with your 17-digit Vehicle Identification Number (VIN). We cannot program and ship your module without it.
What is the difference between a PCM and an ECM?
PCM stands for Powertrain Control Module and ECM stands for Engine Control Module. For these GM vehicles, the terms are often used interchangeably. The PCM is the main computer that controls both the engine functions and the transmission functions.
Is any additional programming required after I install it?
No! This module arrives pre-programmed with the latest GM software for your specific VIN. The only additional step you may need is a simple security relearn procedure, which does not require any special tools.
Why is it important that the module is flashed with the newest updates?
Vehicle manufacturers often release software updates to fix bugs, improve transmission shifting, and enhance engine performance. Programming with the latest software ensures your vehicle benefits from these improvements, providing better-than-original operation.
What if I have a different service number on my original module?
This module replaces several service numbers, including 89017750, 12582605, 12589463, 12602802, and 28042802. As long as your original part number is on this list, our module will be a compatible replacement.