B2380 — Heater Coolant Temp sensor circuit Short to GND

OBD2 code B2380 flags a problem with the engine cooling and temperature control (heater coolant temp sensor circuit short to GND). Short, gentle driving to a shop is usually possible. Common culprits: low coolant level or air in the system, water pump or radiator issues, thermostat stuck open or closed.

body electrical

Is it safe to drive?

Drive with caution Drive with caution and watch the temperature gauge. A thermostat stuck open mainly costs fuel; any sign of overheating means stop immediately — driving an overheating engine destroys head gaskets and worse.

How to diagnose with an OBD scanner

Read the code and freeze frame Connect an OBD2 scanner, confirm B2380 is stored, and save the freeze frame data — it shows engine conditions when the fault was detected.
Check for companion codes and TSBs Related codes often reveal the real root cause. Also check manufacturer technical service bulletins (TSB) for your make and model — many B0xxx issues have factory fixes or software updates. Search by VIN on the manufacturer site or nhtsa.gov.
Inspect wiring and connectors Visually inspect the wiring harness and connectors related to the engine cooling and temperature control for damage, corrosion, chafing or poor contact.
Subsystem check Watch coolant temperature in live data during warmup — it should climb smoothly to operating temperature.
Subsystem check Check coolant level and feel upper/lower radiator hoses to verify thermostat operation.
Verify the repair Clear the code, complete a full drive cycle including the conditions from the freeze frame, and confirm B2380 does not return.

Approximate repair cost

Repair cost depends on which component actually failed. Typical scenarios for B2380 (parts and labor, USD, independent shop rates): Cooling system repair (pump, fan, radiator): $300–$1,200; Replace the thermostat: $150–$400; Replace the coolant temperature sensor: $100–$300. Overall, fixing B2380 usually costs between $100 and $1,200. An accurate diagnosis before buying parts saves money — the most expensive scenario is rarely the first one to check.

Common questions

Will B2380 clear itself?

Sometimes B2380 clears after a few drive cycles if the fault was intermittent — for example a loose connector or a tank of bad fuel. The underlying cause usually remains, so the code tends to return. Clear it once; if it comes back, diagnose rather than erase it repeatedly.

How do I diagnose B2380 myself?

Start with a scan: confirm B2380, save the freeze frame and note any companion codes. Then inspect the wiring and connectors related to the engine cooling and temperature control, and verify the suspect component against live data before buying parts.

How much does it cost to fix B2380?

Cooling system repair (pump, fan, radiator) — $300–$1,200; Replace the thermostat — $150–$400; Replace the coolant temperature sensor — $100–$300. Exact cost depends on the root cause, your vehicle and local labor rates — a proper diagnosis is the cheapest first step.

What are the symptoms of B2380?

Drivers most often notice: overheating warnings in severe cases, poor cabin heat, temperature gauge reads low or never reaches normal, increased fuel consumption.

What does OBD2 code B2380 mean?

When the diagnostic scanner pulls code B2380, the engine control module is reporting a specific electrical fault in the engine cooling and temperature regulation system. Specifically, the module has detected a short circuit to ground in the heater coolant temperature sensor circuit. This falls under the body electrical category in the OBD2 standard, which handles many vehicle comfort and auxiliary systems beyond pure engine management.

The control module continuously watches the signal coming from the coolant temperature sensor. Under normal operation, this sensor changes resistance as engine coolant heats up and cools down, providing the ECU with real-time temperature data. When the module sees voltage readings that indicate a direct short to ground—meaning the circuit is being pulled to battery ground instead of following the expected resistance curve—it logs B2380. The code typically triggers after the fault is present for a set number of drive cycles, preventing false alarms from momentary glitches. Freeze frame data captured alongside the code records engine RPM, load, temperature, and vehicle speed at the exact moment the fault was detected, giving you a snapshot of conditions when things went wrong.

The ECU sets this code to protect the engine and alert the driver. Without accurate coolant temperature data, the engine may run richer than needed, heating systems may not activate properly, and cooling fan operation can become erratic. Addressing B2380 restores proper temperature sensing so the vehicle can manage engine heat effectively.

Common Symptoms of B2380

Drivers with this code active often notice several related problems that stem from incorrect temperature readings.

The Check Engine Light or warning indicator illuminates on the dashboard
Cabin heating performance suffers significantly, especially in cold weather
The temperature gauge stays low or fails to climb to normal operating range
Overheating warnings may appear in more severe cases
Cooling fans run continuously even when the engine is cold
Fuel economy drops due to improper fuel mixture adjustments
The engine may run rougher than normal or stall intermittently

What Causes B2380?

The root cause of B2380 can originate from several points in the cooling system or its electrical connections.

Wiring faults in the heater coolant temperature sensor circuit, including chafing, pinched wires, or insulation damage
Corroded or loose electrical connectors at the sensor or ECU
A failed coolant temperature sensor with internal shorting
Low coolant level or air trapped in the system affecting sensor readings
A faulty thermostat stuck in the open position
Water pump or radiator issues causing abnormal temperature changes
Failed cooling fan motor or fan relay causing secondary electrical problems

How to Diagnose B2380

Proper diagnosis prevents unnecessary part replacement and ensures you fix the actual problem.

Connect an OBD2 scanner and verify B2380 is stored. Save all freeze frame data—this shows exactly what conditions existed when the fault triggered.
Check for additional diagnostic trouble codes. Related codes often point to the underlying issue. Review manufacturer technical service bulletins for your specific make and model; many B0xxx codes have documented factory fixes or software updates available through the manufacturer website or NHTSA database.
Perform a thorough visual inspection of the wiring harness and connectors associated with the engine cooling and temperature control system. Look for damaged insulation, corrosion, broken wires, or connectors that are not fully seated.
Monitor coolant temperature in live data mode while the engine warms up. The reading should climb smoothly to normal operating temperature, typically 195-220°F depending on your vehicle.
Inspect coolant level in the overflow tank or radiator, and verify the upper and lower radiator hoses for proper heatup to confirm thermostat operation.
Clear the code, then complete a full drive cycle that reproduces the conditions shown in the freeze frame data. Verify B2380 does not return before considering the repair complete.

Repair Options for B2380

Addressing the most common and affordable causes first saves money and reduces repair time.

Replace the coolant temperature sensor: $100–$300
Replace the thermostat: $150–$400
Cooling system repair including water pump, fan, or radiator: $300–$1,200

How Much Does It Cost to Fix B2380?

Repair costs depend entirely on which component is actually responsible for the short circuit. Typical scenarios at independent shop rates include sensor replacement at $100–$300, thermostat replacement at $150–$400, and more extensive cooling system work ranging from $300–$1,200. Overall, fixing B2380 typically falls between $100 and $1,200 depending on the underlying cause. An accurate diagnosis before purchasing parts is essential—the most expensive repair scenario is rarely the actual problem.

Can You Drive with B2380?

This code warrants caution. Monitor your temperature gauge closely if the vehicle seems to run normally. A stuck-open thermostat primarily affects fuel economy, but any sign of overheating means stop immediately. Continuing to drive an overheating engine risks catastrophic head gasket failure, warped cylinder heads, and engine seizure. If temperatures climb into the red zone, pull over and allow the engine to cool before investigating further.