P0597 — Thermostat Heater Control Circuit/Open

What Does P0597 Mean?

P0597 is a diagnostic trouble code indicating: Thermostat Heater Control Circuit/Open. This code relates to the vehicle speed and idle control system. It has been reported in NHTSA complaints across 1 different vehicle models.

Symptoms of P0597

⚠️ Check engine light illuminated

Common Causes

🔍 Sensor or control module malfunction

Real Owner Reports

From NHTSA complaint database — actual owner descriptions.

"DRIVING THE RADIO CUTS IN AND OUT MEANWHILE SERVICE STABILITRAC WARNING COMES ON. DOES THIS AROUND 6-12 TIMES IN A 30 MINUTE DRIVE TO AND FROM WORK. ON A FEW INSTANCES THE VEHICLE LOST ALL POWER WHILE DRIVING. THIS OCCURES ON A DAILY BASIS. THIS HAPPENS WHILE DRIVING AND AT A STAND STILL. ALSO "
— Chevrolet Cruze owner, 10/18/2015

Source: NHTSA Complaints Database

Most Reported Vehicles for P0597

Based on NHTSA owner complaint data.

#	Vehicle	Reports
1	CHEVROLET CRUZE

Frequently Asked Questions

Why does my car idle rough?

Idle control codes often point to vacuum leaks, dirty throttle body, or faulty idle air control valve. A cleaning may fix it ($50-100 DIY).

Can a dirty throttle body cause this?

Yes. Carbon buildup on the throttle body is a common cause. Cleaning it is an easy and cheap first step ($10 in throttle body cleaner).

What To Do Next

Possible Fixes

🔧 Have the code scanned with a professional-grade scanner to read freeze frame data
🔧 Test the relevant sensor(s) with a multimeter before replacing
🔧 If DIY repair isn't feasible, get a diagnostic from a trusted mechanic ($50-150)

1
Find your vehicle above
Click your make and model for real owner reports and common causes specific to your vehicle.
2
Check for recalls
Go to nhtsa.gov/recalls and enter your VIN. Free repairs if covered.
3
Get a professional diagnosis
A code alone doesn't identify the exact failed part. A diagnostic ($50–$150) pinpoints the root cause.

P0597: Thermostat Heater Control Circuit/Open