Electronic Control Module Power Relay Sense Circuit Low
Table of contents
P0689 MERCURY Possible Causes
- 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 do I fix code P0689 MERCURY?
Check the “Possible Causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector’s pins.
Cost of diagnosing the P0689 MERCURY code
The cost of diagnosing the P0689 MERCURY code is 1.0 hour of labor. The auto repair labor rates vary by location, your vehicle’s make and model, and even your engine type. Most auto repairs shops charge between $75 and $150 per hour.
Possible Symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
P0689 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.