P0685 on Nissan
ECM/PCM Power Relay Control Circuit/Open
P0685 on Nissan vehicles indicates ecm/pcm power relay control circuit/open. Au7o has documented this code across 1 Nissan model — most commonly on Altima. 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 Nissan by Model
Nissan Altima(1 issue)
- Engine Control Module Relay / ECM Power Interruption Causing Stall or No-Start2002-2006
A well-documented problem on 2002-2006 Altima involves failure of the engine control module (ECM) relay, which can interrupt power to the ECM while driving or prevent the car from starting. Owners report sudden stalling, intermittent crank-no-start, or an engine that dies and restarts after cooling down. Nissan issued a safety recall because relay heat damage and internal failure could cause an unexpected engine stall.
Looking for P0685 on a different make?
View P0685 across all makes →Frequently Asked Questions
What does P0685 mean on Nissan?▼
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 Nissan specifically, this code is documented across 1 model.
What causes P0685 on Nissan vehicles?▼
Common causes on Nissan: 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 Nissan?▼
Repair costs vary widely depending on the root cause and specific Nissan model.
Which Nissan models have P0685 documented?▼
Au7o has documented P0685 on 1 Nissan model: Altima.