Auto Shift Manual Control Circuit Range/Performance
The P0951 code indicates that the Powertrain Control Module (PCM) has detected a malfunction in the auto shift manual control circuit, which is responsible for allowing the driver to manually select gears in an automatic transmission. This circuit typically involves a switch or sensor that communicates the driver's gear selection to the PCM. The 'Range/Performance' aspect means the signal from the circuit is outside the expected range or the circuit is not performing correctly, often due to electrical issues or component failure.
1. Symptoms You Will Notice
- Check Engine Light illuminated
- Inability to manually shift gears
- Transmission stuck in a single gear
- Erratic shifting behavior
2. Most Common Causes
- Faulty manual shift control switch (paddle shifters or selector lever)
- Open circuit or short to ground/battery in the switch wiring
- Loose, corroded, or damaged connectors or terminals in the circuit
- Internal TCM/PCM failure (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 loose connections.
Step 3: Test the auto shift manual control switch with a multimeter for proper resistance and continuity.
Step 4: Check for any technical service bulletins (TSBs) related to the vehicle model.
Step 5: If all else fails, test the PCM for proper operation or reprogram if necessary.
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 typically ranges from $50 to $150 for diagnosis and repair, depending on the root cause and labor rates.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.