P0689: ECM/PCM Power Relay Sense Circuit Low
What Does P0689 Mean?
P0689 is a diagnostic trouble code indicating: ECM/PCM Power Relay Sense Circuit Low. This code relates to the computer and output circuits system. It has been reported in NHTSA complaints across 3 different vehicle models.
Common Causes
- 🔍 Worn or fouled spark plugs
- 🔍 Wiring or connector problem
P0689 Reports by Year
Real Owner Reports
From NHTSA complaint database — actual owner descriptions.
"The contact owns a 2018 Chevrolet Malibu. The contact stated that there was a failure near the fuse box. Additionally, there was a grinding sound coming from the vehicle while the brake pedal was depressed. There were no warning lights illuminated. The contact stated that the engine warning light wa"
— Chevrolet Malibu owner, 02/20/2026
"The dealer ( P & C Auto of Vance SC) used a code reader to clear out safety codes before the car was purchased. After having a diagnostic test done, a mechanic was able to show the codes and when they were cleared. He recommended returning the car back as it was not safe to operate. I would like to "
— Chevrolet Traverse owner, 10/06/2023
"Vehicle stalls intermittently. Due to an earlier recall of the same model but not including the one I own. There is electrical shorting inside the fuse box in the ignition circuitry that causes this problem. This is a huge problem as there is no preemptive warning. Whether you're driving 5 mph or 55"
— Gmc Acadia owner, 05/12/2024
Source: NHTSA Complaints Database
Most Reported Vehicles for P0689
Based on NHTSA owner complaint data.
| # | Vehicle | Reports |
|---|---|---|
| 1 | CHEVROLET MALIBU | |
| 2 | CHEVROLET TRAVERSE | |
| 3 | GMC ACADIA |
Frequently Asked Questions
Does this mean my car's computer is bad?
How much does an ECM replacement cost?
What To Do Next
Possible Fixes
- 🔧 Have the code scanned with a professional-grade scanner to read freeze frame data
- 🔧 Inspect wiring harness and connectors for damage, corrosion, or loose connections
- 🔧 If DIY repair isn't feasible, get a diagnostic from a trusted mechanic ($50-150)
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1
Find your vehicle above
Click your make and model for real owner reports and common causes specific to your vehicle.
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2
Check for recalls
Go to nhtsa.gov/recalls and enter your VIN. Free repairs if covered.
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3
Get a professional diagnosis
A code alone doesn't identify the exact failed part. A diagnostic ($50–$150) pinpoints the root cause.