P0690 Fault Code

ECM/PCM Power Relay Sense Circuit High

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

The P0690 fault code indicates a problem with the ECM/PCM (Engine Control Module/Powertrain Control Module) power relay sense circuit. This circuit is essential for supplying power to the ECM/PCM to ensure it operates properly. When this code is triggered, it often means that the voltage supply is higher than expected, which could be due to a wiring fault, a faulty relay, or issues in the ECM itself.

What are the symptoms of the P0690 code?

Vehicle symptoms associated with P0690 may include:

• Engine stalling or not starting at all.
• Malfunctioning of other electrical components in the vehicle.
• Battery draining quickly due to excessive power draw.
• Potential check engine light illumination on the dashboard.

What causes the P0690 code?

Common causes of the P0690 fault code include:

• High voltage in the power supply circuit due to a short circuit.
• A malfunctioning ECM/PCM power relay.
• Damaged wiring or connectors in the circuit.
• Internal failure of the ECM/PCM.
• Poor ground connections affecting voltage levels.

How to fix P0690?

To resolve the P0690 error code, follow these steps:

1. Inspect the power relay and wiring for any visible damage or corrosion.
2. Test the ECM/PCM power relay to ensure it is functioning properly; replace if necessary.
3. Use a multimeter to measure the voltage in the sense circuit to identify any irregularities.
4. Inspect ground connections and repair any faults found.
5. If no issues are found in the wiring or relay, further diagnostic testing of the ECM/PCM may be required.