Auto Shift Manual Mode Circuit High
The P0958 code indicates that the Powertrain Control Module (PCM) has detected a high voltage condition in the auto shift manual mode circuit. This circuit is responsible for allowing the driver to manually select gears in an automatic transmission. A high voltage reading suggests a short to power, a faulty sensor, or a wiring issue, which can prevent the transmission from shifting properly.
1. Symptoms You Will Notice
- Check Engine Light illuminated
- Transmission stuck in automatic mode or unable to shift manually
- Erratic shifting or transmission hesitation
- Reduced fuel economy
2. Most Common Causes
- Short to power in the manual mode circuit wiring
- Faulty manual mode switch or sensor
- Corroded or damaged connector
- Faulty PCM (rare)
3. Step-by-Step Diagnosis
Step 1: Use an OBD2 scanner to confirm the code and check for other related codes.
Step 2: Visually inspect the wiring and connectors for damage, corrosion, or shorts.
Step 3: Test the manual mode switch/sensor with a multimeter for proper resistance and voltage.
Step 4: Check for a short to power by measuring voltage at the circuit with the ignition on.
Step 5: If all else fails, test the PCM or consult a professional for further diagnosis.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive with this code as it can cause unpredictable shifting, potentially leading to transmission damage or unsafe driving conditions.
How much does it cost to fix?▼
The cost to fix P0958 typically ranges from $50 to $150 for parts and labor, depending on the cause and vehicle model.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.