Code
B1671
LAND ROVER
B — Body
Battery module voltage out of range
Views:
UK: 10
EN: 23
RU: 11
AI status
Completed
Completed
100%
Causes
- Weak, discharged or overcharged 12V battery
- Faulty battery monitoring sensor or battery module
- Poor or corroded battery/ground connections
- Open/short or high-resistance wiring between battery and control module
- Faulty charging system (alternator/regulator) causing under- or over-voltage
- Body control module (BCM) or battery monitoring module fault or software issue
Symptoms
- DTC B1671 illuminated and/or battery warning lamp on dash
- Intermittent electrical faults or parasitic drains
- Possible difficulty starting the vehicle or slow cranking
- Accessory or body systems resetting or behaving erratically
- Jump-start or charging system warnings
What to check
- Read and record freeze frame and live data from vehicle scan tool (battery voltage, battery module data, status flags)
- Measure battery terminal voltage with a quality multimeter (engine off and engine running)
- Inspect battery terminals, harness connectors and ground straps for corrosion, tightness and damage
- Check charging system output (alternator voltage and regulator function) under load
- Perform visual inspection of battery monitoring module and associated wiring for water damage or chafing
- Check for other stored codes (U- or P-codes) that indicate communication or charging faults
Signal parameters
- Expected battery voltage (engine off): ~12.2–12.8 V (charged battery)
- Expected battery voltage (engine running): ~13.5–14.8 V (alternator regulating)
- DTC threshold: battery module/BCM detects voltage outside calibrated upper/lower limits (manufacturer specific)
- Sampling: voltage typically sampled continuously or at ignition events; compare instantaneous and averaged values
- Communication: battery module transmits voltage data over CAN/vehicle network to BCM
Diagnostic algorithm
- Connect a calibrated scan tool and read all stored/active DTCs and relevant freeze frame data. Note voltage values and timestamps.
- Visually inspect battery, terminals, ground straps and battery-monitoring module connectors. Clean and tighten terminals as required.
- With engine off, measure battery terminal voltage at the battery posts using a DVM. Compare to expected charge (12.2–12.8 V).
- Start engine and measure charging voltage at battery posts. Confirm alternator output is within ~13.5–14.8 V. Investigate alternator if out of range.
- Backprobing: monitor live voltage values reported by the battery module and compare to direct battery measurements. Look for disagreement or intermittent spikes.
- Wiggle test harness and connectors while observing live data for intermittent faults. Check for corrosion, water ingress, damaged pins.
- If wiring and connections are good but reported voltages are incorrect, test/replace the battery monitoring sensor/module or its connector as per service manual.
- Check for BCM or network communication errors (U-codes). If present, follow module communication diagnostics before replacing hardware.
- Apply battery load test or replace battery if capacity is low or internal resistance high. Re-test after battery service.
- Clear codes, perform relevant relearn/calibration procedures if module or battery was replaced, then road/test to confirm the fault does not return.
- If the problem persists, consult manufacturer technical service bulletins and consider software reflash of BCM/battery module before component replacement.
Likely causes
- Low battery state of charge or failing battery causing voltage below threshold
- Loose or corroded battery terminals or poor ground causing inaccurate readings
- Battery sensor/module failure or internal fault in the battery pack monitor
- Alternator/regulator producing excessive voltage (overcharging)
- Faulty wiring between battery and battery monitoring/BCM (short to ground or open circuit)
Fault status
Status
Battery module voltage is outside the allowed range. Check battery condition, charging system, wiring and battery monitoring module.
Repair difficulty: Medium
Diagnostic time: 1-3 hours
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Code
B1671
Other
B — Body
Battery Module Voltage Out Of Range
Views:
UK: 17
EN: 35
RU: 20
AI status
Completed
Completed
100%
Causes
- Weak, discharged or overcharged 12V battery
- Faulty battery monitoring sensor or battery module
- Poor or corroded battery/ground connections
- Open/short or high-resistance wiring between battery and control module
- Faulty charging system (alternator/regulator) causing under- or over-voltage
- Body control module (BCM) or battery monitoring module fault or software issue
Symptoms
- DTC B1671 illuminated and/or battery warning lamp on dash
- Intermittent electrical faults or parasitic drains
- Possible difficulty starting the vehicle or slow cranking
- Accessory or body systems resetting or behaving erratically
- Jump-start or charging system warnings
What to check
- Read and record freeze frame and live data from vehicle scan tool (battery voltage, battery module data, status flags)
- Measure battery terminal voltage with a quality multimeter (engine off and engine running)
- Inspect battery terminals, harness connectors and ground straps for corrosion, tightness and damage
- Check charging system output (alternator voltage and regulator function) under load
- Perform visual inspection of battery monitoring module and associated wiring for water damage or chafing
- Check for other stored codes (U- or P-codes) that indicate communication or charging faults
Signal parameters
- Expected battery voltage (engine off): ~12.2–12.8 V (charged battery)
- Expected battery voltage (engine running): ~13.5–14.8 V (alternator regulating)
- DTC threshold: battery module/BCM detects voltage outside calibrated upper/lower limits (manufacturer specific)
- Sampling: voltage typically sampled continuously or at ignition events; compare instantaneous and averaged values
- Communication: battery module transmits voltage data over CAN/vehicle network to BCM
Diagnostic algorithm
- Connect a calibrated scan tool and read all stored/active DTCs and relevant freeze frame data. Note voltage values and timestamps.
- Visually inspect battery, terminals, ground straps and battery-monitoring module connectors. Clean and tighten terminals as required.
- With engine off, measure battery terminal voltage at the battery posts using a DVM. Compare to expected charge (12.2–12.8 V).
- Start engine and measure charging voltage at battery posts. Confirm alternator output is within ~13.5–14.8 V. Investigate alternator if out of range.
- Backprobing: monitor live voltage values reported by the battery module and compare to direct battery measurements. Look for disagreement or intermittent spikes.
- Wiggle test harness and connectors while observing live data for intermittent faults. Check for corrosion, water ingress, damaged pins.
- If wiring and connections are good but reported voltages are incorrect, test/replace the battery monitoring sensor/module or its connector as per service manual.
- Check for BCM or network communication errors (U-codes). If present, follow module communication diagnostics before replacing hardware.
- Apply battery load test or replace battery if capacity is low or internal resistance high. Re-test after battery service.
- Clear codes, perform relevant relearn/calibration procedures if module or battery was replaced, then road/test to confirm the fault does not return.
- If the problem persists, consult manufacturer technical service bulletins and consider software reflash of BCM/battery module before component replacement.
Likely causes
- Low battery state of charge or failing battery causing voltage below threshold
- Loose or corroded battery terminals or poor ground causing inaccurate readings
- Battery sensor/module failure or internal fault in the battery pack monitor
- Alternator/regulator producing excessive voltage (overcharging)
- Faulty wiring between battery and battery monitoring/BCM (short to ground or open circuit)
Fault status
Status
Battery module voltage is outside the allowed range. Check battery condition, charging system, wiring and battery monitoring module.
Repair difficulty: Medium
Diagnostic time: 1-3 hours
Similar codes
Your experience will help others
+100 karma for a short comment :)
Was this AI description helpful?
Your feedback helps improve AI descriptions.
👍 Like
0
👎 Dislike
0
Send to email