P0597 on Jeep
Thermostat Heater Control Circuit Open
P0597 on Jeep vehicles indicates thermostat heater control circuit open. Au7o has documented this code across 3 Jeep models — most commonly on Commander, Compass, Patriot. 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 Jeep range from $60 to $1,000, 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 Jeep by Model
Jeep Commander(1 issue)
- Engine Overheating / Cooling System Failures2006-2010
The Commander is susceptible to engine overheating caused by failing water pumps, cracked radiator tanks, leaking heater core connections, and thermostat failures. The radiator end tanks (plastic) are prone to cracking at the seam where they meet the aluminum core. Power steering cooler line leaks can also compound cooling issues. The 4.7L V8 is especially vulnerable.
Jeep Compass(1 issue)
- Thermostat Housing Coolant Leak2007-2017
The plastic thermostat housing on the 2.0L and 2.4L World engines is prone to cracking and leaking coolant. The housing warps from heat cycling, causing the O-ring seal to fail. This leads to external coolant leaks, overheating, and potential engine damage if not addressed. The same housing is used across Compass, Patriot, and Dodge Caliber platforms.
Jeep Patriot(2 issues)
- Thermostat Housing Coolant Leak / Cracking2007-2017
The plastic thermostat housing on the 2.0L and 2.4L World engines cracks from heat cycling, causing coolant leaks and potential engine overheating. This is the same design flaw shared with the Jeep Compass and Dodge Caliber that use the same engine family. The plastic becomes brittle over time and cracks at the O-ring seal area.
- Engine Overheating / Water Pump and Radiator Fan Failure2007-2017
Beyond the thermostat housing issue, the Patriot suffers from additional cooling system failures including water pump failure, radiator fan motor burnout, and radiator cap failure. The water pump can develop an internal leak that mixes coolant into the engine oil, causing severe engine damage. The radiator fan may stop working intermittently, leading to overheating in slow traffic or idle.
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View P0597 across all makes →Frequently Asked Questions
What does P0597 mean on Jeep?▼
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 Jeep specifically, this code is documented across 3 models.
What causes P0597 on Jeep vehicles?▼
Common causes on Jeep: 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 Jeep?▼
Repair costs on Jeep range from $60 to $1,000, depending on the specific model and root cause.
Which Jeep models have P0597 documented?▼
Au7o has documented P0597 on 3 Jeep models: Commander, Compass, Patriot.