P0655 — Engine RPM Output Circuit Malfunction
Can drive — fix at your convenience.
What P0655 means
This code means the computer detected a fault in the circuit that outputs the engine's RPM signal to another device, such as a tachometer or an external module. It usually points to damaged wiring, a poor connection, or a fault in the receiving component. Repairs are generally simple wiring or connector fixes and rarely involve the engine itself.
Common symptoms
- Check engine light is on
- Tachometer reads incorrectly or not at all
- A connected accessory or module misbehaves
- No noticeable change in how the engine runs
- Intermittent gauge or signal glitches
Common causes
- Damaged or broken wiring in the RPM output circuit
- Loose or corroded connector
- Faulty tachometer or receiving module
- Short to ground or to power in the signal wire
- Engine control module output fault (less common)
Typical repair cost
$80 – $300
Varies by vehicle and root cause.
Frequently asked questions
Can I keep driving with a P0655 code?
Yes, in nearly all cases. This code affects an output signal, not the engine's ability to run. You can drive normally, but it's still smart to have it checked so any connected gauge or device works properly.
How much does it cost to fix a P0655 code?
Most repairs are inexpensive, usually $80 to $200 for wiring or connector work. If a receiving component like a tachometer needs replacing, it may reach around $300.
Is a P0655 code serious?
No, it's generally a low-severity code. It usually doesn't affect drivability, though it's worth fixing so your gauges and connected systems read correctly.
Will P0655 affect how my engine runs?
Almost never. This circuit only outputs an RPM signal to another device, so the engine itself keeps running normally. The main effect is on whatever component relies on that signal.