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.
SYS.OK|MANUAL.DB● LIVE
HOMESERVICE MANUALSOLDSMOBILE1998ACHIEVA 3.1 M, 4T40E/MN4REPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT CARSECTION 5 (BODY CONTROL MODULES)DIAGNOSTIC TESTSDTC B3127: DRIVER DOOR UNLOCK OUTPUT SHORT TO GROUND OR OPENTESTING
1998 Oldsmobile Achieva 3.1 M, 4T40E/MN4
DTC B3127: Driver Door Unlock Output Short To Ground Or Open: Testing
1998 Oldsmobile Achieva 3.1 M, 4T40E/MN4SECTION Testing
WARNING: This page is about a different car, the 1999 Pontiac Grand Am and 1999 Oldsmobile Alero. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
If circuit is shorted to ground, fuse will blow. Check fuse before performing diagnostics.
- Perform BCM DIAGNOSTIC SYSTEM CHECK under SYSTEM TESTS. Go to next step.
- Check operation of power door locks. Repair as necessary. See appropriate wiring diagram in POWER DOOR LOCKS & REMOTE KEYLESS ENTRY SYSTEMS article. Go to next step.
- If driver's door lock operates properly, go to step 11 . If driver's door lock does not operate properly, go to next step.
- Replace driver's door unlock relay with known-good relay. Driver's door unlock relay is located on in the LH instrument panel junction block. If driver's door lock now operates properly, go to next step. If door lock does not operate properly, go to step 6 .
- Replace driver's door unlock relay. After repairs, go to step 11 .
- Disconnect LH instrument panel junction block connector C1. Connect test light between LH instrument panel junction block connector C1 terminal C10 (Yellow wire) and ground while pressing door lock switch to UNLOCK position. See WIRING DIAGRAMS . If test light comes on, go to next step. If test light does not come on, go to step 8 .
- Replace LH instrument panel junction block. After repairs, go to step 11 .
- Disconnect BCM connector C3. Using DVOM, measure resistance of Yellow wire between BCM connector C3 terminal A2 and ground. See Figure . If zero resistance (infinite) is indicated, go to step 10 . If any resistance is indicated, go to next step.
- Repair short to ground in Yellow wire between BCM and door unlock relay. After repairs, go to step 11 .
- Replace BCM. See BODY CONTROL MODULE under REMOVAL & INSTALLATION. After repairs, go to BCM DIAGNOSTIC SYSTEM CHECK under SYSTEM TESTS.
- Using scan tool, clear DTCs. Go to BCM DIAGNOSTIC SYSTEM CHECK under SYSTEM TESTS.
RENDER: 1.0x
NO RELATED
Recommended Tools & Savings
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra cost to you.
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.