AutoCodes – Saturn – P0685 Saturn

P0685 Saturn Code - Engine Control Module Power Relay Control Circuit Open

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: P0685 Saturn indicates Engine Control Module Power Relay Control Circuit Open.
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 7,955

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
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code P0685 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 P0685 Saturn - Engine Control Module Power Relay Control Circuit Open - AutoCodes.com — P0685 Saturn Code - Engine Control Module Power Relay Control Circuit Open

What does this mean?

What are the Possible Causes of the DTC P0685 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 P0685 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 does this mean?

Code Tech Notes

Check all the Engine Control Module (ECM) fuses, if the fuses are OK, then replacing the ECM relay should take care of the problem.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0685 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 P0685 Saturn code?

Need more information on how to fix the P0685 Saturn code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P0685 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 P0685 Saturn Code

1. What are the common symptoms associated with OBDII code P0685 in a Saturn?

The common symptoms of OBDII code P0685 in a Saturn include engine stalling, difficulty starting the engine, and illuminated Check Engine Light.

2. What does the OBDII code P0685 in a Saturn indicate?

OBDII code P0685 in a Saturn indicates a problem with the Engine Control Module Power Relay Control Circuit being open.

3. What are the possible causes of OBDII code P0685 in a Saturn?

Possible causes of OBDII code P0685 in a Saturn include a faulty engine control module power relay, damaged wiring or connectors in the relay circuit, or a malfunctioning engine control module.

4. How can I diagnose the OBDII code P0685 in my Saturn?

Diagnosing OBDII code P0685 in a Saturn involves checking the engine control module power relay for proper operation, inspecting the wiring and connectors for any damage, and testing the engine control module for functionality.

5. Can I drive my Saturn with OBDII code P0685?

It is not recommended to drive your Saturn with OBDII code P0685, as it can lead to engine stalling and other potential issues that may affect driving safety.

6. How can I repair OBDII code P0685 in my Saturn?

Repairing OBDII code P0685 in a Saturn typically involves replacing the faulty engine control module power relay, repairing any damaged wiring or connectors, or replacing the engine control module if necessary.

7. Is it possible to reset OBDII code P0685 in a Saturn without fixing the underlying issue?

Resetting OBDII code P0685 without addressing the underlying issue will only temporarily turn off the Check Engine Light. The code will likely reappear once the problem persists.

8. Are there any preventative measures to avoid OBDII code P0685 in a Saturn?

To prevent OBDII code P0685 in a Saturn, it is advisable to perform regular maintenance checks, such as inspecting the engine control module power relay and the related wiring for any signs of wear or damage.

9. How serious is OBDII code P0685 in a Saturn?

OBDII code P0685 in a Saturn is considered a serious issue as it can lead to engine performance problems, stalling, and potential safety hazards while driving.

10. Can a DIY enthusiast fix OBDII code P0685 in a Saturn?

A DIY enthusiast with experience in automotive repairs may be able to fix OBDII code P0685 in a Saturn by following proper diagnostic procedures and using the necessary tools. However, if unsure, it is recommended to seek professional assistance.