Back to 2020 Subaru Outback
Help
2020 SUBARU OUTBACK
2.5L H4•AWD•CVT•gas
6 active safety recalls on this vehicle — view recalls
Founding sponsor spot is openYour name on every procedure for this vehicle, permanently.Sponsor — $99 →
Repairs0Labor483Torque3298Fluid9DTC1127Battery1Maintenance0Recalls6
P1560low severityPowertrain

Back-Up Voltage Circuit Malfunction

on 2020 Subaru Outback 2.5L H4 · AWD

What this code means

The PCM has detected a malfunction in the back-up voltage circuit. This circuit provides battery voltage to the PCM memory to preserve adaptive learning values and stored data when the ignition is off.

Symptoms

  • Check Engine Light
  • Loss of PCM adaptive memory on each key-off
  • Slightly rough idle after restart
  • Fuel trim relearning each drive cycle

Common causes

  • Blown back-up power fuse
  • Corroded battery cable or terminal
  • Wiring open in back-up voltage circuit
  • Faulty back-up power relay
  • Battery in poor condition

Diagnostic steps

  1. Check back-up voltage fuse
  2. Measure back-up circuit voltage at PCM connector with key off
  3. Inspect battery terminals for corrosion
  4. Test back-up power relay
  5. Check wiring continuity

Repair notes

Replace the blown fuse or repair wiring in the PCM back-up voltage circuit.

🔌 Don't have a code reader?
Any of these will read and clear this code — pick by how deep you want to go.
Budget handheld~$40
ANCEL AD410 →
No-phone-needed handheld — reads, clears, live data, freeze frame.
✓ ANCEL official store
Serious DIY~$100
BlueDriver Pro →
Enhanced codes (ABS, airbag, TPMS) plus repair reports.
SHOP FAVORITE
Shop-grade tablet~$300
Autel MaxiCOM MK808S →
Bidirectional tests, service resets, all systems.
✓ Autel official store
Pro diagnostics$1,500+
Autel MaxiSys MS906 Pro →
Full-system pro platform — topology mapping, ECU coding, the works.
✓ Autel official store
As an Amazon Associate and Autel/ANCEL partner, OLP earns from qualifying purchases — how we link. This never changes the specs we publish.

Other Powertrain codes on this vehicle

🔌 Need this data in your app? It's all in the free API →
🔧 Database maintained under the daily editorial review of Chris Hackleman · Master Technician · 20+ years and Jeff Moore · Master Mechanic · 20+ years. Spot an error? Use the Help link above — a human reads every report.
Stuck on this repair? Take it to The Diag Desk — ask a master tech about this exact car → real human answer within 24h, never AI
Share:XRedditFBWhatsAppThreadsEmail
⚠ STILL BEHIND THE PAYWALL
The 2020 Subaru Outback repair data is incomplete because no one has sponsored it yet. For $99, we generate the full step-by-step procedures, then fact-check them with a second AI pass and your expert review. Your name on every procedure, permanently.
The same data would cost $169/mo from Mitchell1 or $30/year from ALLDATAdiy — and you'd be renting access, not freeing it. Sponsor once, free forever.
Sponsor the Subaru Outback — $99 →
Building an app?
Free API access to all this data — 10 requests/day, no card required.
Get an API key →
Run a shop?
Manage repairs, estimates, and customers with ShopBase — $249/mo, all features included.
Try ShopBase →