Fitment notes: Side post terminals typical for GM vehicles of this era
As an Amazon Associate, OLP earns from qualifying purchases — how we link. This never changes the specs we publish.
Every control module on the 1984-1994 Chevrolet S10 Blazer — where it lives, replacement time, and what it takes to program a replacement. Modules marked dealer / factory tool won't work after a part swap alone — budget for programming.
Electronic Brake Control Module / ABS Control Module (EBCM)1.5 hr R&Rrelearn only +0.2 hrwith ABS (optional, standard on some late models)▸ programming details
📍 left frame rail near master cylinder, or integrated with BPMV (Brake Pressure Modulator Valve) under hood driver side
🔧 Tech 1 or drive cycle
⚠️ Kelsey-Hayes 4WAL (4-Wheel Anti-Lock) system common; requires bleeding and sensor relearn after replacement. Module often integrated with hydraulic modulator assembly.
⚠️ 1984-1991 use replaceable PROM chips for calibration; 1992-1994 can use Tech 1 for diagnostics but PROM replacement still required for recalibration. 1984-1985 use 160-baud ALDL; 1986+ use 8,192-baud ALDL with 12-pin connector.
Transfer Case Control Module (TCCM)1.2 hr R&Rno coding
📍 Behind dash near steering column or on transfer case (electronic shift models only, 1991-1994)
⚠️ Only on models with electronic push-button 4WD shift-on-the-fly; manual shift transfer cases have no module
⚠️ Most S10 Blazers use analog clusters with no module; digital clusters with electronic modules rare and typically found on higher trim levels. Analog clusters require no coding.
Electronic Climate Control Module (ECCP)1.0 hr R&Rno coding
📍 Behind center dash HVAC control panel (electronic climate control models only)
⚠️ Only on models with electronic automatic climate control; most S10 Blazers have manual HVAC with no module
📍 passenger side interior, behind kick panel or under seat
🔧 PROM chip replacement or Tech 1 (1992+)
⚠️ Only present on electronically-controlled 4L60-E automatic; earlier 700R4 and TH350/400 transmissions use hydraulic control only. TCM may be integrated with ECM on some 1992-1993 models.
Sensing Diagnostic Module / Diagnostic Energy Reserve Module (SDM/DERM)0.8 hr R&Rno codingwith airbag (1992-1994, optional then standard)
📍 center console area under dash, or behind center trim panel
⚠️ Driver airbag introduced 1992 model year; passenger airbag added 1994. Battery must be disconnected 10+ minutes before service. No programming required but crash data stored.
Vehicle Anti-Theft System / Pass-Key Module (VATS)0.5 hr R&Rrelearn only +0.3 hrwith VATS (optional, late 1990s introduction)▸ programming details
📍 integrated with ignition lock cylinder and ECM; separate decoder module behind dash on some models
🔧 Tech 1 or 10-minute relearn procedure
⚠️ VATS (Vehicle Anti-Theft System) uses resistor pellet in key; if present, requires resistance matching and relearn. Not common on S10 Blazer until very late in generation; more typical on 1995+ models.
Radio / Entertainment System (Radio)0.5 hr R&Rrelearn only +0.1 hr▸ programming details
📍 center dash, DIN or double-DIN slot
🔧 Theftlock code entry via radio buttons
⚠️ Delco radios with Theftlock feature (1990+) require code entry after battery disconnect or replacement. Code typically on card with owner's manual or retrievable from dealer with VIN.
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 1985 Chevrolet S10 Blazer 2.5L I4 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.