P0685 on Mitsubishi
ECM/PCM Power Relay Control Circuit/Open
P0685 on Mitsubishi vehicles indicates ecm/pcm power relay control circuit/open. Au7o has documented this code across 1 Mitsubishi model — most commonly on Outlander. An open or general fault in the control circuit for the ECM/PCM main power relay. The module cannot properly control the relay that supplies its own switched power.
Common Causes of P0685
- •Faulty ECM/PCM power relay
- •Open in the relay control circuit
- •Corroded/damaged connectors
- •Blown fuse
- •Internal PCM driver fault
P0685 on Mitsubishi by Model
Mitsubishi Outlander(1 issue)
- Defective Engine Control / Power Supply Relay Causes Stall, Power Loss or Overheating (Recall 17V609 / SR-17-005)2015-2017
A relay supplier used an improper maintenance procedure on its welding machine, so internal welds inside several relays used in the Outlander's engine-bay relay box were made incorrectly and can lose proper electrical conduction. Depending on which relay is affected, the result differs: failure of the engine control unit relay kills the engine while driving and the vehicle cannot be restarted; failure of the relay feeding the MIVEC variable valve lift assembly triggers a check engine light and reduced power; failure of the radiator fan relay stops the cooling fan and lets the engine overheat. Because it is a manufacturing defect in a specific production batch rather than a wear item, failures show up suddenly and at low mileage.
Looking for P0685 on a different make?
View P0685 across all makes →Frequently Asked Questions
What does P0685 mean on Mitsubishi?▼
P0685 stands for "ECM/PCM Power Relay Control Circuit/Open." An open or general fault in the control circuit for the ECM/PCM main power relay. The module cannot properly control the relay that supplies its own switched power. On Mitsubishi specifically, this code is documented across 1 model.
What causes P0685 on Mitsubishi vehicles?▼
Common causes on Mitsubishi: Faulty ECM/PCM power relay, Open in the relay control circuit, Corroded/damaged connectors, Blown fuse, Internal PCM driver fault. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0685 on a Mitsubishi?▼
Repair costs vary widely depending on the root cause and specific Mitsubishi model.
Which Mitsubishi models have P0685 documented?▼
Au7o has documented P0685 on 1 Mitsubishi model: Outlander.