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 responding to manual shift commands.
01. Most Common Causes
- Short to power in the manual mode circuit wiring
- Faulty manual mode switch or sensor
- Corroded or damaged connector in the circuit
- Failed PCM (rare)
02. Symptoms You Will Notice
- Transmission stuck in automatic mode
- No response when using manual shift paddles or lever
- Check Engine Light illuminated
- Transmission may enter limp mode
03. Step-by-Step Diagnosis
Step 1: Use a scan tool to retrieve all codes and freeze frame data.
Step 2: Visually inspect the manual mode switch and wiring for damage, corrosion, or shorts.
Step 3: Test the manual mode switch resistance and compare to specifications.
Step 4: Check for voltage at the switch connector with key on; should be within spec.
Step 5: If wiring and switch are okay, test the PCM for proper operation.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive with this code as it may cause unpredictable transmission behavior or limp mode, which can be dangerous.
How much does it cost to fix?▼
The cost typically ranges from $50 to $150 for diagnosis and repair, but can be higher if the PCM needs replacement.