OBD
OBDIICSU

P1660

Severity: Low

Output Circuit Check Signal High

Last updated: July 2026

System
Powertrain
Subsystem
Computer Output Circuit
Code Type
Manufacturer-specific

What does P1660 mean?

P1660 is a manufacturer-specific powertrain diagnostic trouble code. It is defined as "Output Circuit Check Signal High". It falls under the computer output circuit area of the vehicle’s powertrain system, and its exact meaning can vary between manufacturers.

When is P1660 set?

The onboard diagnostic system sets P1660 when it detects a condition matching "output circuit check signal high" in the computer output circuit circuit or system. When the fault is confirmed, the module stores the code and, in most cases, turns on a warning light.

This code is generally minor and often relates to a signal, range or performance condition. It should still be inspected, especially if it returns after clearing.

Common symptoms

Possible causes

What to check first

  1. Scan for all stored and pending codes and note the freeze-frame data
  2. Inspect the wiring and connectors for the affected circuit
  3. Check for related leaks, loose components or obvious damage
  4. Test the relevant sensor and its reference/ground with a meter
  5. Clear the code and retest to see whether it returns

Frequently asked questions

What does the P1660 code mean?

P1660 means "Output Circuit Check Signal High". It is a manufacturer-specific powertrain trouble code in the computer output circuit area.

Is it safe to drive with a P1660 code?

This code is usually minor, and short-distance driving is often possible, but you should still have it checked — especially if the warning light stays on or the code returns.

How do I fix a P1660 code?

There is no single fix. Start by confirming the code with a scan tool, then work through the likely causes and checks above — inspecting wiring, connectors and the relevant components before replacing any parts. On your specific make, confirm the diagnosis before repairs.

Can I clear the P1660 code myself?

You can clear the code with an OBD-II scan tool, but if the underlying fault is still present it will usually return. Clearing without repair is only useful to confirm whether the fault is active.

Related codes

Important

This information is provided for general reference only. It is not repair advice and may not apply to every make or model. Manufacturer-specific codes can differ. Always confirm a diagnosis with a scan tool and, where needed, a qualified technician before replacing parts.