What Does B1981 Mean?
This code indicates that the Body Control Module (BCM) has detected a short to battery voltage (constant 12V+) in the memory off switch circuit. The memory off switch is typically used to disconnect power to memory-retained accessories like power seats, mirrors, or radio presets when the vehicle is not in use. The BCM detected voltage present on the switch signal wire when none should exist, indicating the circuit is shorted to a power source rather than being controlled by the switch.
Common Causes
40%
Damaged wiring harness with insulation worn through, causing the memory off switch signal wire to contact a battery voltage wire
30%
Faulty memory off switch with internal short circuit connecting the signal line directly to battery voltage
20%
Corroded or damaged connector terminals at the switch or BCM allowing cross-circuit contamination with adjacent power circuits
10%
Failed Body Control Module with internal short circuit on the memory switch input circuit
Diagnostic Steps
1
Step 1: Disconnect the memory off switch connector and measure voltage at the harness side signal wire terminal with ignition off using a digital multimeter. Expected reading should be 0 volts; if battery voltage (12V+) is present, the short is in the wiring harness between the switch and BCM.
2
Step 2: With switch still disconnected, inspect all visible wiring between the memory switch and BCM for damaged insulation, pinched wires, or evidence of contact with hot battery voltage circuits. Pay special attention to areas where harnesses pass through metal body panels or near sharp edges.
3
Step 3: If no voltage was found at the harness in Step 1, reconnect the switch and measure voltage at the switch output terminal while manually operating the switch. The switch should only show battery voltage in one position; if voltage is present in both positions or continuously, replace the switch.
4
Step 4: Inspect all connectors in the circuit for corrosion, pushed-out pins, or evidence of water intrusion. Clean connectors with electrical contact cleaner and apply dielectric grease before reassembly.
5
Step 5: If all wiring and switch test correctly, monitor the BCM memory switch circuit using live data while wiggling the harness to verify intermittent shorts. If no issues found, suspect BCM internal fault and verify by checking technical service bulletins for known BCM issues.
6
Step 6: After repairs, clear codes, operate the memory switch through all positions multiple times, and verify the code does not return using active test functions if available.
Estimated Repair Cost
$75 - $450
Parts + labor, varies by vehicle and location
This code indicates that the Body Control Module (BCM) has detected a short to battery voltage (constant 12V+) in the memory off switch circuit. The memory off switch is typically used to disconnect power to memory-retained accessories like power seats, mirrors, or radio presets when the vehicle is ...
The most common cause of B1981 (Memory Off Switch Circuit Short to Battery) is: Damaged wiring harness with insulation worn through, causing the memory off switch signal wire to contact a battery voltage wire
Typical repair costs for B1981 range from $75 to $450, depending on the vehicle, location, and whether you do it yourself or go to a shop.
This is safe to drive as it only affects convenience memory functions for accessories. The code does not affect vehicle operation, steering, braking, or critical safety systems, though some memory features may not function correctly until repaired.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to B1981 to identify the root cause.
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Quick Info
Category
Body
System
Body Control/Memory Systems
Difficulty
Type
Manufacturer
Recommended Tools
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