P0698 Fault Code

Sensor Reference Voltage C Circuit Low

• What does that mean?
• Symptoms
• Causes
• Solutions

The P0698 fault code indicates that there is an issue with the Sensor Reference Voltage C Circuit being too low. This code typically relates to the vehicle's onboard computer and its ability to monitor various signals from sensors. A low reference voltage can lead to incorrect sensor readings, impacting engine performance and other vehicle functions.

• The reference voltage is crucial for ensuring that the sensors operate correctly.
• When the voltage is lower than expected, the Engine Control Module (ECM) may struggle to interpret sensor data accurately, resulting in potentially poor vehicle performance.

What are the symptoms of the P0698 code?

Vehicle owners may experience a variety of symptoms when the P0698 code is triggered, such as:

• Engine performance issues, including rough idling or stalling.
• Decreased fuel efficiency due to incorrect readings.
• Activation of the check engine light on the dashboard.
• Inconsistent or faulty readings from related sensors, which may trigger other fault codes.

What causes the P0698 code?

Several factors can contribute to a P0698 fault code, including:

• Damaged wiring or poor connections in the reference voltage circuit.
• Faulty sensors that are drawing too much power or shorting.
• Issues with the Engine Control Module (ECM) itself.
• Corrosion or damage in connectors related to the sensor circuit.

How to fix P0698?

To resolve a P0698 fault code, consider the following steps:

• Inspect the wiring and connectors for damage or corrosion; repair or replace as necessary.
• Test the voltage at the reference circuit to ensure it is within specifications.
• Check the associated sensors and their connectors for faults; replace any defective parts.
• If all else fails, consider testing or replacing the ECM, though this should be a last resort after ruling out other issues.