Code
B1379
ALFA ROMEO
B — Body
Oil change reset button short to ground
AI status
Completed
Completed
100%
Causes
- Damaged or frayed wiring on the oil change reset switch circuit
- Connector corrosion or bent pins at the switch or body control module (BCM)
- Short to ground due to chafing against bodywork or metal brackets
- Failed oil change reset switch (internal short)
- Faulty BCM/input circuit with internal short or damaged pull‑up resistor
- Aftermarket accessories or recent repairs that disturbed the harness
Symptoms
- Service/oil change reset function will not operate or be ignored
- Stored B1379 (Oil change reset button short to ground) in BCM
- Possible warning or service indicator lamp not resetting
- Intermittent or constant detection of the switch being pressed
What to check
- Read and record freeze‑frame and related codes with a diagnostic scanner
- Visually inspect switch, connector, and harness for damage or corrosion
- Backprobe the switch input at the BCM and at the switch with ignition on
- Measure continuity from the switch input wire to ground (with ignition off)
- Measure resistance across the switch while operating it
- Wiggle test wiring while monitoring the input signal/scan data for changes
Signal parameters
- Expected: Open/Released = pulled‑up to module reference (typically ~5 V logic or near battery via resistor); Pressed = ~0 V to ground
- Measured fault: near 0 V at the switch input with switch released (indicates short to ground)
- Continuity test: near 0 Ω from input wire to chassis ground if shorted; high/infinite if open
- Switch resistance: closed =
Diagnostic algorithm
- Retrieve codes and any related history using a compatible scanner; note whether code is current or historic.
- Visually inspect the reset switch, surrounding trim, and harness for obvious damage, water ingress, or pinched wiring.
- Disconnect connector at the reset switch. With ignition on, backprobe the switch harness pin at the vehicle side: a good circuit should show the pulled‑up voltage (see signal params). If voltage is ~0 V with connector disconnected, the short is downstream toward the BCM.
- If the input is pulled to the correct voltage with switch disconnected, measure across the switch terminals while operating it. Replace the switch if it does not change state or shows internal short.
- If the harness is shorted, disconnect the BCM connector and measure the input pin at the BCM. If the short disappears when BCM disconnected, suspect internal module fault; if short remains, trace wiring harness from switch to BCM searching for chafes, grounding points, or aftermarket connections.
- Repair any damaged wires (splice, replace sections, or replace harness) and clean/repair corroded connectors. Use dielectric grease on connectors after repair.
- Clear codes, perform switch operation and verify the code does not return. Recheck module input voltages and operation with a scan tool.
- If the fault persists and wiring is good, consider replacing the BCM or consulting manufacturer repair information for module bench testing procedures.
Likely causes
- Wiring chafe or pinched section between switch and BCM
- Corroded/loose connector at the switch or module
- Failed/reset switch internally shorted to ground
Fault status
Status
B1379 — Oil change reset button input circuit shorted to ground. The BCM detects constant ground on the service reset switch line, preventing normal reset detection.
Repair difficulty: Medium
Diagnostic time: 0.5-2.0 hours
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