P0605 OBD-II Trouble Code: Internal Control Module ROM Error

Our certified mechanics come to you · 12-month, 12,000-mile warranty

SCHEDULE P0605 DIAGNOSTIC Get a fair and transparent estimate upfront
Red-stars EXCELLENT RATING ON

Cost of diagnosing the P0605 code

P0605 is a diagnostic trouble code (DTC) for "Internal Control Module ROM Error". 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 $70.00. Once we are able to diagnose the problem, you will be provided with an upfront quote for the recommended fix and receive $30.00 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$70.00$30.00
Toyota$70.00$30.00
BMW$70.00$30.00
SCHEDULE P0605 DIAGNOSTIC Get a fair and transparent estimate upfront

Internal Control Module ROM Error (Module Identification Defined by SAE J1979)

What the P0605 code means

The Engine Control Module (ECM) is responsible for many major vehicle functions such as ignition timing, anti lock-braking, fuel injection, traction control, electronic power steering (most new makes of vehicles have this) cooling fan operation and emission controls. It is also responsible for smaller tasks such as window operation, radio, and even the horn.

ROM stands for Read Only Memory. The memory consists of parameters the Engine Control Module stores inside of a processor that can not be erased. The Parameters include tests and numeric ranges that the ECM permanently stores for use every time the vehicle is operated in any way. The parameters are several guidelines of how the processor should interpret the codes, and values being sent to it from things including, but not limited to oxygen sensors, mass air flow (MAF) sensors, interior buttons, crank position sensors, and other forms of engine management.

If the information sent to the Engine Control Module does not match the values that are stored in the processor by the manufacturer, a Check Engine Light will occur. There is a possibility that the memory stored in the ECM has been lost or disrupted if a code P0605 occurs.

What causes the P0605 code?

  • Defective or interrupted Engine Control Module ground or power supply
  • Broken Solder point(s) on the circuit board(s) of the ECM from heat or vibrations
  • Loss of memory in the ECM
  • ECM needs to be updated or re-flashed

What are the symptoms of the P0605 code?

  • A Check Engine Light being set
  • Engine misfire
  • Possibly a no start condition
  • Engine stall or hesitation

How does a mechanic diagnose the P0605 code?

  • Checks the related Technical Service Bulletins (TSB’s) and recalls to determine if the Engine Control Module may need an update, flash, or reprogramming

  • Inspects the wires connecting to the ECM

  • Inspects the electrical terminals connecting to the ECM

  • Tests the ECM for proper ground points and power supplies

Common mistakes when diagnosing the P0605 code?

  • Failing to research whether there is a TSB or recall related to updating, flashing, or reprogramming the Engine Control Module

  • Deeming the ECM as bad without verifying that the power supply and grounds to the ECM are good

How serious is the P0605 code?

It is fairly serious and should be addressed immediately. Think of it like this: The Engine Control Module is essentially the mind of a vehicle. Much the same to the operations of a human brain. They both run off of electricity. Similar to how a brain will control functions of a body such as heart rate, breathing rate and motor skills.

The vehicle itself can be compared to the body of oneself. If a brain undergoes any error, there may be a loss in bodily functions. If the ECM has an error, there may be a loss in sufficient control of vehicle functions: the heart rate, (which is, indirectly, ignition timing,) breathing rate, (which is, indirectly, the amount of air a car will suck in through its intake in accordance to the driver demands,) and motor skills. In this case, motor skills can be used as a literal term because a motor is an engine, and the skills are what the ECM uses to control the motor.

What repairs can fix the P0605 code?

  • Repairing a faulty ground or power supply such as corroded components and damaged wiring

  • An Engine Control Module update, reprogramming or reflash (if applicable)

  • Replacing the ECM

Additional comments for consideration regarding the P0605 code

A new Engine Control Module must be programmed to the vehicle. Oftentimes, a reprogramming can only be done with specialty equipment that is commonly only available to the dealership, though some sources other than the dealership may have that equipment. I suggest that you ask the potential installer of the ECM if they have the necessary specialty equipment in order to complete the job.

Need help with a P0605 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.

trouble codes
Check Engine Light
P0605

Fast and easy Check Engine Light is on Inspection service at your home or office.

SCHEDULE P0605 DIAGNOSTIC
Get a fair and transparent estimate upfront

Recent Check Engine Light is on Inspection reviews

Excellent Rating


YourMechanic Check Engine Light is on Inspection Service

Average Rating

4.5/5

Number of Reviews

3,936

Rating Summary
3,597
169
44
25
101
3,597
169
44
25
101

Abdul

8 years of experience
279 reviews
Abdul
8 years of experience
He was on time and got straight to business. He was very nice
1999 BMW 740I - CHECK ENGINE LIGHT IS ON - ATLANTA, GEORGIA

Patrick

30 years of experience
865 reviews
Patrick
30 years of experience
Friendly and on time
2004 TOYOTA RAV4 - CHECK ENGINE LIGHT IS ON - KYLE, TEXAS

James

27 years of experience
331 reviews
James
27 years of experience
James was highly efficient and friendly. Great job.
2003 HONDA ELEMENT - CHECK ENGINE LIGHT IS ON - ORLANDO, FLORIDA

Jerome

21 years of experience
246 reviews
Jerome
21 years of experience
Dude replaced my sensor with no issue, pointed out that i had a gasket leak and booked a next day appointment on the spot. Pretty straightforward guy. Will update review after second appointment
2003 TOYOTA CAMRY - CHECK ENGINE LIGHT IS ON - GWYNN OAK, MARYLAND

More related articles

P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
The Traveler’s Guide to Driving in Malaysia
CraigBurrows / Shutterstock.com Malaysia is a popular destination for many tourists today. The country has amazing sights and attractions that you will want to explore....
Veteran and Military Driver Laws and Benefits in Idaho
The state of Idaho offers a number of benefits and perks for those Americans who have either served in an Armed Forces branch in the...

Related questions

Q: The car starts, but when I hit the gas the check engine light blinks & it feels like I don't get much power, sometimes smell gas.

Hello. A flashing Check Engine Light is an indicator that the computer has detected an issue with the vehicle's engine management system that could potentially cause harm to the emissions system. Continuing to drive with a flashing Check Engine...

Q: My SUV is running hard and has the Diagnostic Trouble Code P0016

Hi and thanks for contacting Your Mechanic. The code P0016 is for the crankshaft position sensor. Check the wiring harness to the sensor that is located on the bottom of the engine by the crankshaft pulley. Check for voltage and...

Q: P0605 & p2105

Hello, thank you for writing in. Lets take a look at these codes separately at first. The P0605 codes stands for a malfunction with the main computer's (PCM-power train control module) ROM (or "Read Only Memory"). The P2105 is then...

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.

1-800-701-6230 · hi@yourmechanic.com