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

- Code Popularity: 32,172 Views
- Repair Importance Level: 3/3
- Repair Difficulty Level: 3/3
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What are the Possible Causes of the DTC P0685 Acura?

NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
  • Faulty Powertrain Control Module (PCM) Power Relay (PGM-FI Main Relay 1)
  • Powertrain Control Module Power Relay harness is open or shorted
  • Powertrain Control Module Power Relay circuit poor electrical connection
  • Blown Powertrain Control Module fuse
  • Faulty Powertrain Control Module
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How to Fix the DTC P0685 Acura?

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

Code Tech Notes

Check all the Powertrain Control Module (PCM) fuses, if the fuses are OK, then replacing the PCM Power Relay (also label as PGM-FI Main Relay 1) should take care of the problem.

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What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0685 Acura code, it typically requires 1.0 hour of labor. The specific diagnosis time and labor rates at auto repair shops can differ based on factors such as the location, make and model of the vehicle, and even the engine type. It is common for most auto repair shops to charge between $75 and $150 per hour.

What are Code Possible Symptoms?

  • Engine Light ON (or Service Engine Soon Warning Light)

Code P0685 Acura Description

After the ignition switch is turned to LOCK (0) or the engine start/stop button is pressed to select the OFF mode, the Powertrain Control Module (PCM) does not shut down immediately. After finishing a predetermined process according to the
request of each device and system, the power supply is automatically disconnected (self-shutdown function). The PCM power is disconnected by controlling PGM-FI Main Relay 1. During a normal PCM shutdown, the shutdown process is executed by the CPU, PGM-FI Main Relay 1 is turned off, and the voltage to the PCM is turned off to shut down the PCM. When the voltage to the PCM is turned off and the PCM shuts down without the normal shutdown procedure, the PCM detects a malfunction in the PGM-FI main relay 1 control circuit and stores a Diagnostic Trouble Code (DTC).
OBDII Code P0685 Acura - Engine Control Module Power Relay Control Circuit Open - AutoCodes.com
P0685 Acura Code - Engine Control Module Power Relay Control Circuit Open

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