Cruise Control Servo Control Circuit Low
The P0595 code indicates that the Powertrain Control Module (PCM) has detected a low voltage condition in the cruise control servo control circuit. This circuit is responsible for sending commands to the servo actuator that adjusts throttle position to maintain set speed. A low voltage reading suggests a short to ground, open circuit, or faulty component, which can prevent the cruise control system from engaging or functioning properly.
1. Most Common Causes
- Faulty cruise control servo motor
- Short to ground in the servo control circuit
- Open circuit or damaged wiring/connectors
- Failed PCM (rare)
2. Symptoms You Will Notice
- Cruise control inoperative
- Cruise control light on dash flashing or staying on
- Engine Check Light illuminated
- Possible intermittent cruise control operation
3. Step-by-Step Diagnosis
Step 1: Use a scan tool to confirm P0595 and check for other related codes.
Step 2: Visually inspect the cruise control servo wiring and connectors for damage, corrosion, or loose connections.
Step 3: Test the servo control circuit voltage with a multimeter; compare to manufacturer specifications.
Step 4: Check the servo motor resistance and operation; replace if out of spec.
Step 5: If wiring and servo are good, test PCM output signals; consider PCM replacement as last resort.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
Yes, it is generally safe to drive, but cruise control will not work. The vehicle's normal braking and throttle functions remain unaffected.
How much does it cost to fix?▼
Typical repair costs range from $50 to $150 for parts and labor, depending on whether it's a wiring repair or servo replacement.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.