P0654 OBD-II Trouble Code: Engine RPM Output Circuit Malfunction

Our certified mechanics come to you · Get a fair and transparent estimate upfront

Red-stars EXCELLENT RATING ON

Cost of diagnosing the P0654 code

P0654 is a diagnostic trouble code (DTC) for "Engine RPM Output Circuit Malfunction". This can happen for multiple reasons and a mechanic needs to diagnose the specific cause for this code to be triggered in your situation. Our certified mobile mechanics can come to your home or office to perform the Check Engine Light diagnostic for $114.99 . Once we are able to diagnose the problem, you will be provided with an upfront quote for the recommended fix and receive $20.0 off as a credit towards the repair. All our repairs are backed by our 12-month / 12,000-mile warranty.

Cars Estimate Credit towards follow-up repair Earliest Availability
Ford $114.99 $20.0
Toyota $114.99 $20.0
BMW $124.99 $20.0
SCHEDULE P0654 DIAGNOSTIC Get a fair and transparent estimate upfront

P0654 code definition

The P0654 code is stored when the PCM detects a voltage reading from the engine RPM output circuit that does not align with the acceptable range as determined by the manufacturer’s specifications.

What the P0654 code means

During operation, the engine speed is monitored by the PCM through several components. One of these is the Engine RPM Output Circuit, which creates a signal through a grounding process that involves a driver (an internal switch). Each driver is monitored by the PCM through a fault line, sending voltage readings to the PCM for comparison to the manufacturer’s specifications. If the voltage is too high or too low compared to what it is supposed to be in the current operation conditions, the PCM will store the P0654 code.

What causes the P0654 code?

The most common cause behind the P0654 code is a defect in the system circuitry, such as loose or corroded wiring, or loose or broken electrical connectors.

Other causes may include:

  • A faulty instrument cluster
  • An open or shorted instrument cluster harness
  • A faulty tachometer
  • A bad crankshaft or camshaft sensor
  • A faulty PCM, in rare cases

What are the symptoms of the P0654 code?

Most of the time, the illuminated Check Engine light will be the only symptom that the vehicle owner will observe; however, an inoperative or erratic tachometer, and possibly a no start condition, can also occur.

How does a mechanic diagnose the P0654 code?

In order to diagnose the P0654 code, the mechanic should begin by verifying the code with an OBD-II scanner. Once the code has been verified, they should perform a visual inspection of all electrical components, such as wiring and connectors. Because faulty electrical components are the most likely cause of this code, a thorough examination is required. After ensuring that any loose, corroded, or broken components are repaired, the code should be cleared from the PCM and the system should be retested.

If the code comes back after this repair, then the mechanic has diagnosed a more complex issue within the engine RPM output circuit or related components. A specialized scanner, such as an Autohex, may be required to pinpoint the exact area causing the problem. The mechanic should continue checking each component for voltage readings, comparing those to the manufacturer’s specifications, until they’ve discovered the component or sensor that is not operating correctly.

Common mistakes when diagnosing the P0654 code

Most often, mechanics report that a faulty tachometer is blamed, when the PCM driver was actually at fault.

How serious is the P0654 code?

If the P0654 code is detected, it represents an issue that should be addressed right away. This code means that the engine speed cannot be correctly monitored, which could eventually lead to larger issues or dangerous driving conditions.

What repairs can fix the P0654 code?

In order to fix the P0654 code, a technician may attempt several types of repairs. These include:

  • Repair any defects in the system circuitry, replacing loose, corroded, or broken electrical components as necessary.
  • Replace a faulty instrument cluster.
  • Repair an open or shorted instrument cluster harness.
  • Replace a faulty tachometer.
  • Replace a bad crankshaft or camshaft sensor.
  • Replace a faulty PCM, in rare cases.

Additional comments for consideration regarding the P0654 code

If the issue is found to be a bad crankshaft or camshaft sensor, and the part must be replaced, most manufacturers recommended replacing both simultaneously. These sensors work best when they wear at the same time.

Need help with a P0654 code?

YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.

Check Engine Light
trouble codes
P0654

No more waiting rooms! Our mechanics will come to you to diagnose and fix the P0654 code.

SCHEDULE P0654 DIAGNOSTIC
Get a $20 credit for the follow-up repair

Recent Check Engine Light is on Inspection reviews

Excellent Rating

(7400)

Rating Summary
6879
249
58
41
173
6879
249
58
41
173
 at YourMechanic

David

13 years of experience
393 reviews
David
13 years of experience
Chevrolet Malibu L4-2.4L - Check Engine Light is on Inspection - Marietta, Georgia
He explained everything to me in detail on what I needed to know about my car. Definitely recommend him for getting the job done.
 at YourMechanic

Raymond

37 years of experience
402 reviews
Raymond
37 years of experience
Toyota Camry L4-2.2L - Check Engine Light is on - Las Vegas, Nevada
Raymond did a great job however I was charged for two hours labor and he was only here less than 45 minutes. should I expect this on future appointments with your mechanic ?
 at YourMechanic

Shane

17 years of experience
217 reviews
Shane
17 years of experience
Volkswagen EuroVan V6-2.8L - Check Engine Light is on Inspection - Austin, Texas
Arrived on time. Explained the issues he found and how he will fix it. I have parts on order and will schedule an appointment to have Shane install the parts when they arrive.
 at YourMechanic

Kanstantsin

19 years of experience
51 reviews
Kanstantsin
19 years of experience
Ford F-150 V8-4.6L - Check Engine Light is on Inspection - Littleton, Colorado
Kanstantsin arrived early. Was very courteous and professional. Will highly recommend to anyone. Thank you Kanstantsin.


More related articles

Related questions

Engine fan continues to run, Check Engine light on, and coolant leaks.
The two engine fans are controlled by separate relays that are turned on by a powertrain control unit. The system is controlled through the body control module that signals the powertrain control unit. The body control module gets signals from...
Low Fuel Light on with fuel in tank
The fuel level sensors on some of these vehicles tend to be misread by the computer, causing faults in the system. The fuel sensor would need to be inspected, and the engine computer scanned, to see if the codes received...
What is the major problem in my car
Hello. When you have this many codes (https://www.yourmechanic.com/article/how-to-read-and-understand-check-engine-light-codes-by-jason-unrau) you either have an issue with the voltage system in the vehicle being low due to a bad connection, a battery that is failing (https://www.yourmechanic.com/services/battery-replacement), or a faulty alternator (https://www.yourmechanic.com/services/alternator-replacement). It can...

How can we help?

Our service team is available 7 days a week, Monday - Friday from 6 AM to 5 PM PST, Saturday - Sunday 7 AM - 4 PM PST.

1 (855) 347-2779 · hi@yourmechanic.com