AutoCodes – Saturn – P0686 Saturn

P0686 Saturn Code - Engine Control Module Power Relay Control Circuit Low

Quick Answer

The powertrain relay is a normally open relay. Common causes include Weak battery, Low voltage while cranking, Faulty Engine Control Module (ECM) power 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: P0686 Saturn indicates Engine Control Module Power Relay Control Circuit Low.
Common causes: Common causes include Weak battery, Low voltage while cranking, Faulty Engine Control Module (ECM) power 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.

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Code Popularity 1,380

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 Jul 18, 2022

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P0686 Saturn Description

The powertrain relay is a normally open relay. The relay armature is held in the open position by spring tension. Battery positive voltage is supplied directly to the relay coil and the armature contact at all times. The Engine Control Module (ECM) supplies the ground path to the relay coil control circuit via an internal integrated circuit called an Output Driver Module (ODM). The ODM output control is configured to operate as a low side driver for the powertrain relay. The ODM for the powertrain relay also incorporates a fault detection circuit, which is continuously monitored by the ECM. When the ECM commands the powertrain relay ON, ignition 1 voltage is supplied to the ECM, and to several additional circuits.

OBDII Code P0686 Saturn - Engine Control Module Power Relay Control Circuit Low - AutoCodes.com — P0686 Saturn Code - Engine Control Module Power Relay Control Circuit Low

What does this mean?

What are the Possible Causes of the DTC P0686 Saturn?

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

How to Fix the DTC P0686 Saturn?

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 P0686 Saturn 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 P0686 Saturn code?

Need more information on how to fix the P0686 Saturn code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P0686 Saturn 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 P0686 Saturn Code

1. What are the common symptoms of OBDII code P0686 in a Saturn?

The common symptoms of code P0686 in a Saturn may include engine stalling, rough idling, poor acceleration, and difficulty starting the vehicle.

2. What causes the Engine Control Module Power Relay Control Circuit Low code (P0686) in a Saturn?

The P0686 code in a Saturn is typically caused by a faulty engine control module (ECM) power relay, a damaged relay control circuit, or issues with the ECM power supply.

3. How can I diagnose the P0686 code in my Saturn?

Diagnosing the P0686 code in a Saturn involves checking the ECM power relay, inspecting the relay control circuit for damage, and testing the power supply to the ECM using a multimeter.

4. Can a DIY enthusiast repair the P0686 code in a Saturn?

Repairing the P0686 code in a Saturn may require advanced automotive knowledge and tools. It is recommended to consult a professional mechanic for accurate diagnosis and repair.

5. Will driving with the P0686 code in a Saturn cause further damage?

Continuing to drive with the P0686 code in a Saturn can potentially cause damage to the engine control module and other related components. It is advisable to address the issue promptly.

6. How much does it typically cost to repair the P0686 code in a Saturn?

The cost of repairing the P0686 code in a Saturn can vary depending on the extent of the damage and the labor rates of the service provider. It is best to obtain quotes from different mechanics.

7. Can resetting the OBDII system clear the P0686 code in a Saturn?

Resetting the OBDII system may temporarily clear the P0686 code in a Saturn, but if the underlying issue is not addressed, the code is likely to reappear. It is essential to diagnose and fix the root cause.

8. Are there any preventive measures to avoid the P0686 code in a Saturn?

Regular vehicle maintenance, including checking the electrical system and relays, can help prevent issues like the P0686 code in a Saturn. Promptly addressing any warning signs is also crucial.

9. How long does it take to repair the P0686 code in a Saturn?

The repair time for the P0686 code in a Saturn can vary depending on the complexity of the issue and the availability of parts. It is advisable to consult with a mechanic for a more accurate estimate.

10. Can a low battery voltage trigger the P0686 code in a Saturn?

Low battery voltage can potentially trigger the P0686 code in a Saturn due to inadequate power supply to the engine control module. Ensuring the battery is in good condition is essential to prevent such issues.