AutoCodes – Mercury – P0690 Mercury

P0690 Mercury Code - Electronic Control Module Power Relay Sense Circuit High

Quick Answer

The Powertrain Control Module (PCM) monitors the voltage on the Ignition Switch Position Run (ISP-R) and the Fuel Injector Power Monitor (INJPWRM) circuits. Common causes include Weak battery, Low voltage while cranking, Faulty Powertrain Control Module (PCM) relay. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: P0690 Mercury indicates Electronic Control Module Power Relay Sense Circuit High.
Common causes: Common causes include Weak battery, Low voltage while cranking, Faulty Powertrain Control Module (PCM) relay.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

Save to My Repairs My Repairs

AI answers can be wrong. Verify repairs with testing. Open full chat

Code Popularity 1,520

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on May 05, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
Add Comment

💬 Need more help? Ask Coddy for instant answers — it's free!

Code P0690 Mercury Description

The Powertrain Control Module (PCM) monitors the voltage on the Ignition Switch Position Run (ISP-R) and the Fuel Injector Power Monitor (INJPWRM) circuits. This DTC sets when the voltage on the ISP-R and the INJPWRM circuit voltages do not correspond for a calibrated period of time.

OBDII Code P0690 Mercury - Electronic Control Module Power Relay Sense Circuit High - AutoCodes.com — P0690 Mercury Code - Electronic Control Module Power Relay Sense Circuit High

What does this mean?

What are the Possible Causes of the DTC P0690 Mercury?

Weak battery
Low voltage while cranking
Faulty Powertrain Control Module (PCM) relay
Blown PCM fuse
Faulty PCM
PCM harness is open or shorted
PCM circuit poor electrical connection

How to Fix the DTC P0690 Mercury?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0690 Mercury code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

Need more information about the P0690 Mercury code?

Need more information on how to fix the P0690 Mercury code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P0690 Mercury code diagnosed by a professional: Find a repair shop in your area

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P0690 Mercury Code

1. What does the OBDII code P0690 mean for a Mercury vehicle?

P0690 indicates that the Electronic Control Module (ECM) has detected a high voltage issue in the power relay sense circuit.

2. What are the common symptoms of code P0690 in a Mercury?

Symptoms may include failure to start, intermittent stalling, dashboard warning lights, reduced fuel efficiency, or no power to the ECM or related components.

3. What causes the P0690 code to be triggered?

Possible causes include a faulty ECM power relay, damaged wiring or connectors, a blown fuse, or, in rare cases, a failing ECM.

4. Can I drive my Mercury with a P0690 code?

Driving with a P0690 code is not recommended as it may cause further damage to the ECM or leave you stranded due to a sudden loss of power.

5. How is the P0690 code diagnosed in a Mercury?

A technician will perform a visual inspection of the relay, wiring, and connectors, check the voltage at the ECM power relay circuit, and possibly test the ECM itself.

6. How do I fix the P0690 code on my Mercury?

Repairs can include replacing a faulty ECM power relay, repairing or replacing damaged wiring, checking and replacing blown fuses, or, if necessary, replacing the ECM.

7. What tools are needed to repair a P0690 code?

Basic tools such as a multimeter, fuse tester, and OBDII scanner, along with access to the vehicleâ€™s wiring diagram, are typically required.

8. How much does it cost to fix a P0690 code on a Mercury?

Repair costs vary but may range from $50 to $200 for relay or wiring repairs, while ECM replacement can cost $500 to $1,500 or more depending on the model.

9. Can I fix the P0690 code myself?

If you have experience with electrical systems and the necessary tools, you may be able to fix minor issues like replacing a relay or fuse. For more complex issues, professional help is recommended.

10. Will clearing the P0690 code with an OBDII scanner solve the problem?

Clearing the code may temporarily remove the warning, but it wonâ€™t fix the underlying issue. The problem must be properly diagnosed and repaired to prevent the code from returning.