P0516 – Battery Temperature Sensor Circuit Low

System: Powertrain | Standard: ISO/SAE Controlled | Fault type: Circuit Low

Definition source: SAE J2012/J2012DA (industry standard)

P0516 indicates the powertrain control system has detected a low electrical input condition in the battery temperature sensor circuit. In other words, the module is seeing the signal from the battery temperature sensing circuit pulled lower than expected for the current operating conditions, which typically points to a circuit-level problem rather than a confirmed temperature issue. Depending on vehicle design, the sensor may be a dedicated battery temperature sensor, integrated into a battery monitoring unit, or part of a battery current/voltage/temperature assembly. Monitor strategy, enabling conditions, and how the vehicle responds can vary by vehicle, so always verify circuit descriptions, connector views, and test specifications using the correct service information before replacing parts.

What Does P0516 Mean?

P0516 is defined as Battery Temperature Sensor Circuit Low. This means the control module has identified that the battery temperature sensor circuit signal is below the expected electrical range for a calibrated period of time under the conditions when the monitor is active. The key takeaway is that the fault type is circuit low: the diagnostic is centered on an electrical low-input condition (such as a signal shorted to ground, an open in a power/feed or reference path, or excessive resistance causing a voltage drop), not a guaranteed battery overheating or overcooling condition. Exact circuit architecture and how the module reports related data can vary by vehicle.

Quick Reference

• Subsystem: Battery temperature sensor signal circuit (battery temperature sensing input to the powertrain control system).
• Common triggers: Signal short-to-ground, open power/feed or reference to the sensor, high resistance in the signal path, connector terminal issues, or sensor internal failure pulling the signal low.
• Likely root-cause buckets: Wiring/connector faults; sensor or battery monitoring unit fault; power/ground or reference supply issue; less commonly control module input fault.
• Severity: Usually moderate; may affect charging strategy and battery management, potentially leading to charging warnings or battery/starting concerns.
• First checks: Scan for companion codes, inspect sensor/circuit connectors and harness routing, verify power/ground/reference integrity, and compare scan data to a known-good baseline if available.
• Common mistakes: Replacing the battery or sensor without verifying the low-input condition, ignoring shared reference/ground issues, or skipping connector pin-fit and voltage-drop testing.

Theory of Operation

The battery temperature sensor circuit typically uses a temperature-dependent element whose electrical characteristic changes with temperature, and the control module interprets that change as battery temperature. Depending on design, the module may supply a reference feed and monitor a return signal, or a battery monitoring unit may condition the signal and report it to the powertrain system. The input is used to adjust charging behavior and battery protection strategies so the system can avoid overcharging or undercharging across temperature changes.

P0516 sets when the module detects the battery temperature signal is electrically low beyond what it expects during the monitor’s operating window. Common electrical reasons include the signal being pulled toward ground, a missing feed/reference to the sensor, or excessive resistance causing an abnormal drop. The module may also use rationality checks to ensure the signal remains plausible and stable when conditions change.

Symptoms

• Warning light: Check engine light illuminated.
• Charging behavior: Charging system may be managed conservatively, with reduced or inconsistent charging output.
• Battery message: Battery/charging-related warning message or indicator may appear (varies by vehicle).
• Starting: Intermittent weak crank or no-start after sitting, especially if charging control is affected.
• Electrical accessories: Accessory power may be limited or behave inconsistently if the vehicle reduces load to protect battery state.
• Scan data: Battery temperature PID may read an implausible fixed low value or change erratically (depending on how the data is reported).

Common Causes

• Short-to-ground in the battery temperature sensor signal circuit (including chafed insulation contacting metal)
• Open power/feed to the battery temperature sensor (or to the sensor’s internal pull-up circuit, where applicable), pulling the signal low
• High resistance in the sensor power or ground path causing an excessive voltage drop under load
• Connector issues at the sensor or control module: corrosion, moisture intrusion, spread terminals, poor pin fit, or partial disengagement
• Damaged wiring in areas of flex or heat exposure (near battery tray, harness bends, clips, or brackets)
• Battery temperature sensor internal failure resulting in a low (pulled-down) signal
• Reference/return circuit fault shared with other sensors (varies by vehicle), leading to a low reading on this circuit
• Control module input circuit fault (less common), after wiring/sensor integrity is verified

Diagnosis Steps

Tools that help: a scan tool capable of reading freeze-frame data and live data, a digital multimeter, and basic back-probing or breakout leads. Have wiring diagrams and connector views from the correct service information (pin IDs and circuit routing vary by vehicle). A test light may help for loaded power/ground checks, but avoid forcing current through sensitive circuits.

1. Confirm DTCs and capture data. Record P0516, any related electrical codes, freeze-frame, and readiness/monitor status. Clear codes only after saving data so you can verify what changes.
2. Check the basics at the battery area. Inspect battery condition, battery hold-down, tray, and nearby harness routing for pinch points, rubbing, or acid/corrosion contamination that could damage wiring and connectors.
3. Perform a focused visual inspection of the sensor circuit. Locate the battery temperature sensor (location varies by vehicle) and inspect its connector for corrosion, moisture, bent pins, poor pin fit, or broken locking tabs. Repair obvious connector or terminal issues before deeper electrical testing.
4. Use live data to validate the fault behavior. With key on (and when safe to do so), monitor the battery temperature sensor parameter. If it is stuck at an implausibly low value or drops low intermittently, note whether the change correlates with vibration, fan operation, or harness movement.
5. Wiggle test while logging. With live data recording, gently wiggle the sensor connector, nearby harness segments, and the harness path back toward the control module. If the reading suddenly drops low or the DTC resets, isolate the exact section that reacts and inspect it closely for broken conductors or terminal tension issues.
6. Check for a short-to-ground on the signal circuit. Key off, disconnect the sensor (and disconnect the module end if service information recommends). Measure resistance between the signal wire and chassis ground. A low resistance path suggests a short-to-ground or insulation damage; locate by inspecting and separating harness sections until the short disappears.
7. Verify sensor power/feed and ground integrity under load. Key on, back-probe at the sensor connector and confirm the correct feed and ground paths are present per service information. Then perform voltage-drop testing on the ground and power paths while the circuit is loaded (use the vehicle’s normal loading method where applicable). Excessive drop indicates high resistance in wiring, terminals, or splices.
8. Check the signal circuit for opens/high resistance. With connectors unplugged and key off, perform continuity checks end-to-end on the signal conductor, and then perform a loaded continuity test (where appropriate) to reveal hidden high resistance. Inspect any inline splices, junctions, or connector transitions shown in the wiring diagram.
9. Differentiate sensor vs harness fault. If wiring/connector tests pass, follow service information to substitute a known-good input condition without forcing current (method varies by vehicle). If the input remains low when it should respond, suspect sensor internal failure or a module input issue; if it responds normally, re-check for intermittent wiring/terminal faults.
10. Module-side checks (only after circuit integrity is proven). Verify the module has stable power and ground and that no shared reference/return circuit issues are present (varies by vehicle). If all external circuits and the sensor are verified good yet the input remains low, the module input circuit may be faulty.
11. Repair verification. After repairs, clear codes, run the vehicle through the appropriate enable conditions (per service information), and recheck pending/stored DTCs. Review live data to confirm the battery temperature signal is stable and no longer drops low during a repeat wiggle test.

Professional tip: If P0516 is intermittent, prioritize terminal tension and voltage-drop testing over simple continuity checks. A circuit can show continuity with almost no current flow yet still pull the sensor signal low when the module’s input biasing and harness resistance interact. Logging live data during a controlled wiggle test is often the fastest way to pinpoint the exact harness section or connector that triggers the low-input event.

Possible Fixes & Repair Costs

Repair cost for P0516 varies widely because the fault is an electrical “circuit low” condition and the true cause can be anything from a simple connector issue to wiring repair or sensor replacement. Labor and parts needs depend on confirmed test results.

• Clean, reseat, and secure the battery temperature sensor connector; correct any loose pin fit found during inspection
• Repair or replace damaged wiring in the battery temperature sensor signal and return circuits (chafing, corrosion, broken conductors)
• Correct a short-to-ground on the sensor signal circuit or an unintended ground path caused by moisture/corrosion
• Restore proper power/feed or reference supply to the sensor circuit if testing confirms a low condition caused by an open or high resistance in the feed
• Perform voltage-drop-based repairs on affected power/ground paths (terminals, splices, grounds) if excessive drop is verified
• Replace the battery temperature sensor only after verifying wiring integrity and correct circuit operation
• If all external circuit checks pass, diagnose the control module input circuit per service information and repair as applicable

Can I Still Drive With P0516?

You can often drive with P0516, but you should treat it as a warning that the battery temperature sensor circuit signal is reading low and charging strategy may be affected. If you notice a no-start, repeated dead-battery condition, charging warning indicators, reduced electrical performance, or any safety-related warnings, avoid driving and have the system diagnosed promptly.

What Happens If You Ignore P0516?

Ignoring P0516 can lead to ongoing charging-control inaccuracies, which may contribute to battery discharge, shortened battery life, or repeated starting issues. In some cases, the vehicle may limit charging output or set additional electrical system faults, increasing the chance of drivability complaints related to low system voltage.

Related Sensor Battery Codes

Compare nearby sensor battery trouble codes with similar definitions, fault patterns, and diagnostic paths.

• P0E0E – Hybrid/EV Battery Energy Control Module Internal Temperature Sensor Circuit Low
• P0537 – A/C Evaporator Temperature Sensor Circuit Low
• P0517 – Battery Temperature Sensor Circuit High
• P0515 – Battery Temperature Sensor Circuit
• P0514 – Battery Temperature Sensor Circuit Range/Performance
• P0934 – Hydraulic Pressure Sensor Circuit Low

Key Takeaways

• P0516 indicates a verified “battery temperature sensor circuit low” electrical condition, not a confirmed battery or sensor failure by itself
• Most root causes are wiring/connector faults such as shorts to ground, corrosion, or high resistance that pulls the signal low
• Confirm the fault with inspections, wiggle testing, and voltage-drop checks before replacing parts
• Charging behavior can be affected; address the code promptly if you have starting or battery-charging symptoms
• Follow service information for circuit routing, pinouts, and test specifications because designs vary by vehicle

Vehicles Commonly Affected by P0516

• Vehicles that use a dedicated battery temperature sensor mounted near the battery case or tray
• Vehicles with battery temperature sensing integrated into a battery monitoring module or current sensor assembly
• Vehicles with charging systems that adjust alternator output based on inferred battery temperature
• Vehicles operated in environments that accelerate corrosion at battery terminals and nearby connectors
• Vehicles with battery relocations or aftermarket battery installations that stress or reroute sensor wiring
• Vehicles with high underhood heat exposure that can harden insulation and increase harness brittleness
• Vehicles with prior front-end or battery-tray repairs where harness routing or pin fit may have been disturbed
• Vehicles that see frequent short-trip use, increasing sensitivity to charging strategy and electrical load management

FAQ

Is P0516 telling me the battery is too cold?

No. P0516 specifically indicates the battery temperature sensor circuit signal is low from an electrical standpoint (for example, short-to-ground or a feed issue). Temperature may not be abnormal; confirm with scan data and circuit testing.

Can a bad connection cause a “circuit low” code?

Yes. Corrosion, moisture intrusion, loose terminals, or high resistance at a splice/ground can pull a sensor signal low or distort it enough for the module to detect a circuit-low condition. Inspection plus wiggle and voltage-drop testing are key.

Should I replace the battery temperature sensor first?

Not before testing. Because P0516 is a circuit-low fault type, wiring/connector problems are common. Replace the sensor only after verifying the correct feed/reference, return path integrity, and that the signal circuit is not shorted to ground.

Will P0516 affect charging?

It can. Many charging strategies use battery temperature input to adjust charging behavior. If the input is falsely low, the charging system may not behave as intended, which can contribute to low-voltage symptoms or battery health concerns over time.

Will clearing the code fix the problem?

Clearing the code only resets the stored fault. If the underlying circuit-low condition remains, the code will typically return after the monitor runs again. Use clearing only after repairs or as part of a controlled diagnostic confirmation.

For best results, confirm P0516 with a scan tool, inspect the sensor and harness near the battery, and verify wiring integrity with targeted electrical tests before replacing any components.