1990 Chevrolet Blazer 5.7 K, StandardFACTORY OEM SERVICE PROCEDURE

Electronic Control Module (ECM): ECM: Removal

  1. Disconnect negative battery cable. Unplug connectors from ECM (behind glove box). See Figure. Remove ECM from vehicle. To remove PROM, position ECM so bottom cover is facing upward. Remove PROM access cover.
  2. Note reference notch location in PROM and ECM for reassembly reference. Engage end of PROM carrier with hook end of rocker-type PROM remover. Press on vertical bar end of remover and rock engaged end of PROM carrier up as far as possible.
  3. Engage opposite end of PROM carrier in same manner and rock this end up as far as possible. Repeat process until PROM carrier and PROM are free of PROM socket. PROM carrier and PROM should lift off of PROM socket easily.
NOTE: PROM carrier should ONLY be removed with PROM remover. Use of any other method may damage PROM or PROM socket.
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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.

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