P0597 on Chevrolet
Thermostat Heater Control Circuit Open
P0597 on Chevrolet vehicles indicates thermostat heater control circuit open. Au7o has documented this code across 2 Chevrolet models — most commonly on Camaro, Sonic. P0597 is a cooling-system code indicating an open electrical circuit in the control for the heated (electronically controlled) engine thermostat. Many modern engines use a thermostat with a built-in heater element that the computer can energize to open the thermostat sooner for better temperature management and emissions. When the PCM commands that heater but detects no electrical continuity (an open circuit), it sets this code. It generally means the thermostat heater isn't being controlled, which can affect coolant temperature regulation, fuel economy, and emissions. Typical repair costs on Chevrolet range from $150 to $1,800, depending on the specific model and root cause.
Common Causes of P0597
- •Failed thermostat heater element or integrated control thermostat
- •Open or broken wiring to the thermostat heater circuit
- •Corroded, loose, or disconnected thermostat connector
- •Blown fuse or open in the heater power feed
- •Poor ground or control-circuit fault from the PCM
- •Damaged PCM driver for the heater (rare)
P0597 on Chevrolet by Model
Chevrolet Camaro(1 issue)
- Cooling System Problems and Engine Overheating2016-2023
Camaro owners report persistent overheating issues, particularly at idle, caused by cooling fan failures, faulty fan relays, clogged radiators, failing water pumps, and thermostat problems. Temperatures reaching 240-250°F have been reported.
Chevrolet Sonic(1 issue)
- Plastic Thermostat Housing / Coolant Outlet Cracking and Leaking2012-2020
The Sonic uses a molded plastic thermostat housing (coolant outlet) on both the 1.8L LUW/LWE and 1.4L turbo engines. Repeated thermal cycling embrittles the plastic, and the housing cracks at the seams, at the hose-neck stubs, or the integrated O-ring seal takes a set. Coolant weeps down onto the transmission bell housing and the block, so owners often mistake it for a transmission or oil leak. Because the thermostat is integral to the housing, a stuck-open thermostat frequently accompanies the leak, producing slow warm-up and poor heater output. Sonic Owners Forum members list the coolant outlet alongside the surge tank and plastic coolant elbows as a cluster of thermal-fatigue failures that show up on higher-mileage cars. This is a separate component from the water pump, which has its own well-known failure.
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View P0597 across all makes →Frequently Asked Questions
What does P0597 mean on Chevrolet?▼
P0597 stands for "Thermostat Heater Control Circuit Open." P0597 is a cooling-system code indicating an open electrical circuit in the control for the heated (electronically controlled) engine thermostat. Many modern engines use a thermostat with a built-in heater element that the computer can energize to open the thermostat sooner for better temperature management and emissions. When the PCM commands that heater but detects no electrical continuity (an open circuit), it sets this code. It generally means the thermostat heater isn't being controlled, which can affect coolant temperature regulation, fuel economy, and emissions. On Chevrolet specifically, this code is documented across 2 models.
What causes P0597 on Chevrolet vehicles?▼
Common causes on Chevrolet: Failed thermostat heater element or integrated control thermostat, Open or broken wiring to the thermostat heater circuit, Corroded, loose, or disconnected thermostat connector, Blown fuse or open in the heater power feed, Poor ground or control-circuit fault from the PCM. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0597 on a Chevrolet?▼
Repair costs on Chevrolet range from $150 to $1,800, depending on the specific model and root cause.
Which Chevrolet models have P0597 documented?▼
Au7o has documented P0597 on 2 Chevrolet models: Camaro, Sonic.