P0952: Auto Shift Manual Control Circuit Low
The P0952 code indicates that the Powertrain Control Module (PCM) has detected a low voltage condition in the auto shift manual control circuit. This circuit is responsible for communicating the driver's manual shift commands (via paddle shifters or the shift lever) to the transmission control module. A low voltage reading suggests a short to ground, open circuit, or faulty component, which can prevent proper manual shifting operation.
1. Symptoms You Will Notice
- Inability to manually shift gears
- Transmission stuck in automatic mode
- Check Engine Light illuminated
- Reduced fuel economy
- Harsh or erratic shifting
2. Most Common Causes
- Faulty manual shift switch (shift lever or paddle) shorted to ground
- Signal circuit wiring for manual shift shorted to ground
- Corroded, loose, or damaged connectors/terminals in the manual shift circuit
- Internal TCM/PCM failure in the input driver (pull-up resistor)
- CAN bus communication issues if the signal is transmitted via the body control module (BCM)
3. Step-by-Step Diagnosis
Step 1: Use a scan tool to retrieve all stored codes and freeze frame data.
Step 2: Visually inspect the shift lever/paddle shifter wiring and connectors for damage, corrosion, or loose connections.
Step 3: Test the circuit voltage at the TCM/PCM connector using a multimeter; compare with manufacturer specifications.
Step 4: Check for continuity and shorts to ground in the signal wire between the shifter and TCM.
Step 5: If wiring is intact, test the shift lever/paddle shifter assembly per service manual procedures.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is generally safe to drive, but you may lose manual shift capability. If the transmission defaults to a safe mode, you may experience limited performance. Have it diagnosed soon to prevent further issues.
How much does it cost to fix?▼
The cost typically ranges from $50 to $150 for diagnosis and repair, depending on the cause. If a shift lever assembly or TCM replacement is needed, costs can be higher.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.