Engine Control Module (ECM)0.8 hr R&Rrelearn only +0.3 hr▸ programming details
📍 passenger side firewall, mounted on inner fender well near brake master cylinder
🔧 Tech 1 with TIS cartridge or PROM/MEMCAL chip swap
⚠️ TBI engines use MEMCAL chip replacement for programming; ALDL diagnostics only; idle relearn required after installation
Sensing and Diagnostic Module (SDM)0.6 hr R&Rno codingwith supplemental restraint system (1992-1993)
📍 under center console, mounted to floor tunnel
⚠️ Battery disconnect and 10-minute wait mandatory before service; driver airbag only
Radio (RAD)0.5 hr R&Rrelearn only +0.1 hr▸ programming details
📍 Center of instrument panel
🔧 TheftLock code entry
⚠️ TheftLock anti-theft requires code entry after battery disconnect (1990+)
Aftermarket tool coverage varies by software version and vehicle build — treat "aftermarket tool" rows as "usually possible" and verify against your tool maker's coverage list before promising a customer. Spot a wrong location or hour? Tell us — corrections ship fast here.
Size-standard part numbers — verify your connector type before buying. Rear blades are model-specific; check the package's vehicle list.
Fuel economy figures are EPA data via fueleconomy.gov (median across matching trims). Performance figures are compiled estimates for the 1986 GMC Sonoma 2.8L V6 and can vary by trim.
🔧 Database maintained under the daily editorial review of Chris Hackleman · Master Technician · 20+ years and Jeff Moore · Master Lexus & Toyota Mechanic · 20+ years.