Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
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HOMESERVICE MANUALSBUICK1991CENTURY L4-151 2.5L VIN R TBIREPAIR AND DIAGNOSISPOWERTRAIN MANAGEMENTCOMPUTERS AND CONTROL SYSTEMSENGINE CONTROL MODULESERVICE AND REPAIRENGINE CONTROL MODULE (ECM) REPLACEMENT
1991 Buick Century L4-151 2.5L VIN R TBI
Engine Control Module (ECM) Replacement
1991 Buick Century L4-151 2.5L VIN R TBISECTION Engine Control Module (ECM) Replacement
ECM Location Behind Glove Box.:
ECM And PROM Access Cover:
Prom Removal And Tool:
When replacing a production ECM with a service ECM, transfer the broadcast code and production number from the production unit to the service unit. Also, during replacement, the PROM must be removed from the ECM being replaced and transferred to the new unit.
1. Disconnect battery ground cable.
2. Then disconnect two computer electrical connectors.
3. Remove computer mounting hardware.
4. Remove computer from passenger compartment.
5. Reverse procedure to install.
RENDER: 1.0x
NO RELATED
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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.