What does it mean?
P1560 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: Back-Up Voltage Circuit Malfunction .
Symptoms
- Check engine light on and stored codes that clear themselves or reappear after every start
- Learned adaptations are lost each time the ignition is switched off
- Rough idle and poor drivability for the first minutes after every start, until the module relearns
- Automatic transmission shifts harshly until the adaptive values rebuild
- Clock, radio presets and trip data reset on their own
- Hard starting or an intermittent no start condition
Likely causes
- Blown memory or module supply fuse in the engine bay or interior fuse box
- Corroded fuse box terminals, or a fuse holder that no longer grips the blade
- Broken or chafed constant battery feed wire between the fuse box and the module connector
- Poor module ground point, loose ground strap or corrosion under a ground eyelet
- Weak battery or a loose battery terminal that drops voltage during cranking
- Aftermarket alarms, audio equipment or trackers spliced into the back-up feed
- Internal fault in the control module memory supply circuit
How to fix it
- Check and confirm the memory fuse first, and inspect the fuse holder for heat damage and looseness
- With the ignition off, measure battery voltage directly at the module back-up supply pin
- Perform voltage drop tests on the supply wire and on the module ground path under load
- Clean and tighten the module ground point and the battery terminals
- Look for aftermarket wiring spliced into the constant feed and remove any poor connections
- Load test the battery and confirm the charging system holds correct voltage
- Replace or reprogram the module only after a stable supply and ground have been verified