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Home/Cars/GMC/Sierra/T1XX (2019-Present)/what does a P0155 code mean for GMC Sierra T1XX (2019-Present)

what does a P0155 code mean for GMC Sierra T1XX (2019-Present)

GMC Sierra T1XX (2019-Present)

Error Codes
Severity: mediumDifficulty: mediumError Code: P01551-2 hours
3 min read
484 words

Problem Statement

Learn how to diagnose and fix P0155 oxygen sensor circuit malfunction in GMC Sierra T1XX. Step-by-step guide with diagnostic procedures and repair instructions.

Error Code
P0155
Affected Component
Exhaust System
Estimated Time
1-2 hours

Safety Warnings

  • ⚠Disconnect battery before working on electrical systems.
  • ⚠Allow the exhaust system to cool before handling any components.

Symptoms

  • •Check engine light illuminated
  • •Poor fuel economy
  • •Rough idle
  • •Engine stalling
  • •Increased emissions
  • •Decreased engine performance

Diagnostic Steps

  1. 1Scan for error codes using an OBD-II scanner to confirm P0155 and check for any related codes.
  2. 2Inspect the wiring and connectors for Bank 2, Sensor 1 for signs of damage, corrosion, or loose connections.
  3. 3Measure the voltage and resistance of the oxygen sensor heater circuit with a multimeter.
  4. 4Check the fuse associated with the oxygen sensor heater circuit.
  5. 5Inspect the oxygen sensor for physical damage or contamination.
  6. 6Test the functionality of the oxygen sensor using an oscilloscope if available, to check the output signal.

Solution

Solution

1. Preparation

  • Gather all necessary tools and parts.
  • Disconnect the battery to prevent electrical shock.
  • Raise the vehicle securely on jack stands if necessary for access.

2. Remove the Oxygen Sensor

  • Use an oxygen sensor socket to unscrew Bank 2, Sensor 1 from the exhaust manifold.
  • Carefully disconnect the electrical connector from the sensor.

3. Inspect and Clean

  • Inspect the sensor threads and the surrounding area for carbon buildup; clean if necessary.
  • Check the connector for any signs of corrosion or damage; clean or replace as needed.

4. Install the New Oxygen Sensor

  • Apply anti-seize compound to the threads of the new oxygen sensor (if recommended by the manufacturer).
  • Screw the new sensor into Bank 2, ensuring it is tightened to the manufacturer's specified torque (typically around 30-40 lb-ft).
  • Reconnect the electrical connector securely.

5. Reconnect Battery and Test

  • Reconnect the battery and clear the trouble codes using an OBD-II scanner.
  • Start the engine and allow it to reach operating temperature.

Verification

After completing the repair, verify that the issue has been resolved:

  • ✓Test the affected component to ensure it functions correctly
  • ✓Check for any error codes or warning lights
  • ✓Monitor the vehicle for a few days to ensure the issue does not recur

Prevention Tips

To prevent this issue from occurring again:

  • •Follow the manufacturer's recommended maintenance schedule
  • •Address warning signs early before they develop into major issues
  • •Use quality parts and fluids recommended for your vehicle
  • •Keep detailed records of all repairs and maintenance

Tools & Equipment Required

  • •OBD-II scanner
  • •Oxygen sensor socket
  • •Multimeter
  • •Torque wrench
  • •Jack and jack stands

Parts Required

  • •New oxygen sensor for Bank 2, Sensor 1
  • •Anti-seize compound

Additional Information

Error Code
P0155
Affected Component
Exhaust System
Estimated Time
1-2 hours
Difficulty
medium
Severity
medium
Tools Required
5 items
Parts Required
2 items

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