P0685: How to Diagnose & Fix — ECM/PCM Power Relay Control Circuit/Open
7 vehicles · 5 makes · $100-$1,500 repair
How to diagnose and fix P0685: most-reported vehicles
Ranked by owner reports. Each card gives the symptoms, how to confirm the cause, the fix, parts and sources for that vehicle.
Jeep Wrangler · 2012–2018
The TIPM is the integrated fuse/relay power-distribution module controlling most electrical systems. On many 2007-2018 Chrysler/Jeep vehicles, including the JK Wrangler, the internal fuel-pump relay (and later the other relays) degrades. The first symptom is usually a fuel-pump-relay problem causing hard starts, no-start, or stalling; failures can also present as random gremlins — fuel pump running with the key off, wipers or door locks cycling on their own, or intermittent electrical loads. While Chrysler recalled the 2011-2013 Grand Cherokee/Durango with an external relay, the Wrangler was generally not recalled, leaving owners to repair the module themselves. Dealer TIPM replacement runs ~$1,000-$1,200; repair/rebuild services and external-relay bypass kits are cheaper alternatives.
Common Symptoms
- Hard start, no-start, or stalling (fuel pump not priming)
- Fuel pump running with the ignition off
- Random electrical behavior — wipers, door locks, or lights cycling on their own
- Intermittent dead-vehicle conditions
How to Fix
Confirm the fuel-pump relay as the failure point (fuel pump not priming, no-start). Options: rebuild/repair the existing TIPM (specialist services), install an external fuel-pump relay bypass kit, or replace the TIPM (dealer ~$1,000-$1,200; module ~$400 plus programming). An external relay bypass is the common low-cost fix for the fuel-pump-relay failure mode.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- MAKS TIPM-7 fuel-pump-relay bypassOEMMAKS TIPM-7-FUEL-PUMP-RELAY-BYPASS
Bypass a test-confirmed failed internal fuel-pump relay while retaining ASD safety behavior Fitment/availability: 2012-2018 Wrangler JK with TIPM-7; manufacturer lists all Wrangler variants through 2018.
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Sources for this issue (3)
Dodge Journey · 2009–2013
The under-hood TIPM (a fuse/relay/computer combo) is a known failure point on early Journeys, causing a wide array of erratic electrical behavior. Owners report random horn honking, no-start or hard-start conditions, windows and door locks operating on their own, premature battery drain, and the engine stalling while driving. In severe cases the unit has overheated and caused under-hood fires.
Common Symptoms
- Random horn honking
- No-start / hard-start
- Windows or door locks operating by themselves
- Premature/repeated dead battery
- Engine stalling while driving
- Dashboard lights flickering
How to Fix
Diagnose via dealer or shop; the typical fix is replacing the TIPM module (commonly the integrated fuel-pump relay). Some shops repair just the failed relay circuit at lower cost, but full module replacement is the lasting fix. Average replacement runs around $1,160.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- 04692305 TIPM rebuild/replacement service
Exact-label early-module option after external circuit diagnosis Fitment: Only when the installed TIPM number/options match Live direct US service/product page when checked
- 68143317 TIPM rebuild/replacement service
Exact-label 2.4L branch after diagnosis Fitment: Match installed label, engine and options Live direct US service/product page when checked
As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.
Sources for this issue (1)
Nissan Altima · 2002–2006
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.
Common Symptoms
- engine stalls while driving
- intermittent no-start
- cranks but will not start
- engine restarts after sitting
- loss of power with warning lights illuminated
How to Fix
Confirm recall completion status by VIN first. Diagnosis typically includes checking for ECM power loss, relay operation, and signs of heat damage or intermittent contact in the IPDM/relay circuit. The fix is replacement of the ECM relay with the updated part per recall procedure; if symptoms persist, inspect related fuse box terminals and wiring for overheating or poor pin tension.
Nissan Frontier · 2005–2006
Nissan Xterra · 2005–2006
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P0685 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P0685 mean?
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.
What are the most common causes of P0685?
The most common causes of P0685 are: Faulty ECM/PCM power relay, Open in the relay control circuit, Corroded/damaged connectors, Blown fuse, Internal PCM driver fault. The specific cause varies by vehicle.
How much does it cost to fix P0685?
Repair costs for P0685 range from $100 to $1,500, depending on the vehicle and root cause.
Which vehicles are affected by P0685?
Au7o has documented P0685 across 7 vehicle models from 5 manufacturers: Dodge, Jeep, Mitsubishi, Nissan, RAM.
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.