P1600 on Toyota Vitz (SCP10): Engine computer battery back-up circuit

Short answer: P1600 means “Engine computer battery back-up circuit”. The car’s computer has found a fault in the ECM system and turns on the Check engine light (MIL). First check: check EFI fuse and back-up wiring.

Code

P1600

System

ECM

Dashboard light

Check engine light (MIL)

Also sold as

Toyota Yaris, Toyota Echo (XP10)

Applies to

1SZ-FE (by platform)

Confidence

medium (Toyota Echo 1999–2002 factory diagnostics, same XP10 platform; not confirmed on JDM 1SZ-FE)

Source

carmanualsclub.com

Likely causes

1. Open in back-up power circuit
2. Engine computer (ECM)

What to check, in order

1. Check EFI fuse and back-up wiring

Related on this car

• All fault codes for this car
• Warning lights
• Where the parts are (parts map)
• Common problems

Same code on other cars

• P1600 · Toyota Passo (1st gen)
• P1600 on all cars compared

← P1520 P0710 →

Clearing the code does not fix the fault. If it comes back, the problem is still there. For brakes, airbags and steering, see a trained mechanic.