Shift Solenoid "B" Control Circuit Range/Performance
Diagnostic trouble code P0975 indicates that the Powertrain Control Module (PCM) or Transmission Control Module (TCM) has detected an out-of-range or unexpected performance condition in the control circuit for Shift Solenoid 'B'. The module sets this code when the voltage or current feedback from the solenoid circuit does not match the expected parameters for the commanded gear state.
This code should be addressed promptly to avoid drivability issues. Ignoring it can lead to poor transmission performance, getting stuck in a specific gear, or potential internal transmission damage over time.
Common symptoms
- Illuminated Check Engine Light
- Harsh, delayed, or erratic transmission shifting
- Transmission slipping between gears
- Vehicle stuck in a specific gear (limp mode)
- Decreased fuel economy
Likely causes
- Low or dirty transmission fluid
- Faulty Shift Solenoid 'B'
- Damaged, corroded, or loose wiring and connectors in the solenoid circuit
- Clogged transmission fluid filter or internal hydraulic blockage
- Faulty Transmission Control Module (TCM) or Powertrain Control Module (PCM)
What to check before replacing parts
Check the transmission fluid level and condition.
Look for: Fluid that is significantly low, burnt, or heavily contaminated with debris indicates a fluid issue that could cause solenoid performance problems.
Inspect the wiring harness and connectors for Shift Solenoid 'B'.
Look for: Look for frayed wires, melted insulation, corrosion on pins, or loose connections that could cause an open or short in the circuit.
Measure the resistance of Shift Solenoid 'B' using a digital multimeter.
Look for: Compare the resistance reading to the manufacturer's specification. An infinite reading (open) or a reading significantly out of spec indicates a faulty solenoid.
Check the power and ground circuits to the solenoid.
Look for: Verify that the solenoid is receiving the correct battery voltage and has a solid ground when commanded on by a scan tool.
Perform a transmission line pressure test.
Look for: Pressures that are out of specification can indicate internal hydraulic leaks, a failing pump, or valve body issues affecting solenoid operation.
This page explains the generic P0975 definition and is general reference information, not a diagnosis for your specific vehicle. Actual causes, severity, and repairs vary by make, model, engine, and mileage — always confirm with a scan tool and a qualified technician before replacing parts.
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