Actuator Supply Voltage Circuit High
The P0659 code indicates that the Powertrain Control Module (PCM) has detected a voltage level in the actuator supply voltage circuit that is higher than the specified range. This circuit provides power to various actuators such as idle air control, variable valve timing, and transmission solenoids. A high voltage condition can be caused by a faulty alternator overcharging the system, a short to voltage in the wiring, or a malfunctioning PCM. This can lead to erratic actuator operation and potential damage to electronic components.
1. Most Common Causes
- Short to battery positive (B+) in the actuator 'A' power supply circuit wiring
- Damaged, corroded, or moisture-contaminated connector or harness at the power supply circuit pins
- Faulty actuator with internal short circuit or abnormally low resistance
- Internal failure of the control module (PCM/ECM/TCM) in the power supply driver circuit
- Short circuit between the actuator power supply wire and another circuit with elevated voltage
2. Symptoms You Will Notice
- Check Engine Light illuminated
- Erratic transmission shifting or harsh engagement
- Idle speed fluctuations or stalling
- Reduced fuel economy
3. Step-by-Step Diagnosis
Step 1: Use a scan tool to retrieve all codes and freeze frame data.
Step 2: Inspect the battery and charging system voltage; ensure it is within 12.6-14.5 volts with engine running.
Step 3: Visually inspect the wiring and connectors related to the actuator supply circuit for damage, corrosion, or shorts.
Step 4: Test the actuator supply voltage at the PCM connector using a multimeter; compare to manufacturer specifications.
Step 5: If voltage is high, isolate the circuit by disconnecting actuators one by one to locate the short.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive with this code as high voltage can damage sensitive electronic components and cause unpredictable vehicle behavior. Have it diagnosed promptly.
How much does it cost to fix?▼
Repair costs typically range from $100 to $300, depending on the cause. A faulty alternator replacement may cost $200-$400, while wiring repairs are usually less expensive.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.