The governor pressure sensor in a 46RE transmission plays a crucial role in controlling shift timing and quality. Testing this sensor is essential for diagnosing transmission issues. Here's a comprehensive guide on how to test the governor pressure sensor in a 46RE transmission.

Preparation

Before testing the governor pressure sensor, gather the following tools:

  • Digital multimeter
  • Scan tool with transmission data capabilities
  • Pressure gauge (0-100 PSI range)
  • Basic hand tools for accessing the transmission

Ensure the vehicle is on a level surface and the transmission fluid is at the correct level and temperature.

Visual Inspection

Start with a visual inspection of the sensor and its wiring:

  • Check for any visible damage to the sensor
  • Inspect the wiring harness for frays, cuts, or corrosion
  • Ensure the connector is securely attached

Electrical Testing

Voltage Test

1. Locate the 4-pin connector for the governor pressure sensor

2. Turn the ignition key to the "ON" position without starting the engine

3. Using a digital multimeter, measure the voltage between the following pins:

- Pin 2 (5V supply) and Pin 3 (ground): Should read approximately 5 volts

- Pin 4 (signal) and Pin 3 (ground): Should read about 0.5 volts at idle

Resistance Test

1. Disconnect the sensor connector

2. Measure resistance between Pin 2 and Pin 3 of the sensor

3. The resistance should be between 2.5k to 3.5k ohms

Dynamic Testing

Scan Tool Method

1. Connect a scan tool capable of reading transmission data

2. Start the engine and monitor the following parameters:

- Actual governor pressure

- Desired governor pressure

- Governor pressure sensor voltage

3. Drive the vehicle and observe the readings:

- At idle: Pressure should be near 0 PSI, voltage around 0.5V

- As speed increases: Pressure and voltage should increase proportionally

- At 60 MPH: Pressure should be about 60 PSI, voltage around 3V

Manual Pressure Test

1. Locate the governor pressure port on the transmission

2. Connect a 0-100 PSI pressure gauge

3. Drive the vehicle and compare actual pressure readings to scan tool data

Interpreting Results

  • If voltage remains constant regardless of speed, the sensor is likely faulty
  • If pressure readings don't match expected values, check for mechanical issues
  • Erratic readings may indicate wiring problems or a failing sensor

Troubleshooting

If tests indicate a problem, consider the following steps:

  • Clean the sensor and connector
  • Check for proper ground connection
  • Inspect the wiring harness for damage
  • Replace the sensor if electrical tests fail

Remember, accurate diagnosis often requires a combination of electrical testing and mechanical inspection. If you're unsure, consult a professional transmission specialist.

FAQs About Testing Governor Pressure Sensor 46RE

    • Can a bad governor pressure sensor cause no shifts?
      Yes, a faulty sensor can prevent the transmission from shifting properly or cause it to stay in first gear.
    • How often should the governor pressure sensor be tested?
      It's recommended to test the sensor during regular transmission service or when experiencing shifting issues.
    • Is it possible to clean a governor pressure sensor?
      While cleaning may temporarily improve function, it's generally better to replace a faulty sensor for long-term reliability.