P0066 OBD-II Trouble Code: Air Assisted Injector Control Circuit or Circuit Low

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

SCHEDULE P0066 DIAGNOSTIC Get a fair and transparent estimate upfront
Red-stars EXCELLENT RATING ON

Cost of diagnosing the P0066 code

P0066 is a diagnostic trouble code (DTC) for "Air Assisted Injector Control Circuit or Circuit Low". 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 P0066 DIAGNOSTIC Get a fair and transparent estimate upfront

check engine light logo

P0066 trouble code definition

Air Assisted Injector Control Circuit or Circuit Low

What the P0066 code means

This code indicates that the powertrain control module (PCM) is detecting a voltage from the air assisted injector control circuit that is below specifications. When this low voltage is detected, the idle air/fuel mixture may not be within specifications and will therefore set off a Check Engine Light.

What causes the P0066 code?

This code can be caused by the air assisted injector control wiring or connectors having a short or being damaged in some way. If the air assisted injector control valve is unplugged or has a bad connection, that can also cause this code. There is also an injector control relay that may have gone bad that could cause this code as well.

What are the symptoms of the P0066 code?

Symptoms of this code would include the Check Engine Light being illuminated, slight stumble or hesitation from the engine when the throttle is released, or the engine may die completely in very extreme cases.

The air assisted injector system works to better atomize the fuel during deceleration of the vehicle. If the voltage to the air assisted injector system is too weak to open and close the air assisted injector control valve, the air/fuel mixture may be too rich temporarily during deceleration. This is what would cause the stumble and hesitation. The Check Engine Light comes on due to the fact that this system is connected to the powertrain control module.

How does a mechanic diagnose the P0066 code?

When diagnosing this issue, a mechanic might start with inspecting the air assisted injector system parts such as the air assisted injector valve, wiring, and vacuum hoses that are associated with this system for any faults such as shorted wiring, torn or frayed vacuum hoses, faulty injector valve, or bad electrical connections. This diagnosis would include using a digital multimeter to check voltage at specific points in the circuit to ensure they are within specification as well as a good visual inspection of all parts. Any faults that are found would be noted and repaired at the customer’s earliest convenience.

Common mistakes when diagnosing the P0066 code

Common diagnostic mistakes that could be made during the repair of this issue could include replacing the fuel injectors or the air assisted injector valve without testing their functionality. Replacing any parts without first verifying that the are faulty would be a diagnostic mistake and is also very common.

How serious is the P0066 code?

This code would not be considered very serious due to the fact that it only affects the engine under certain conditions. It would be advised to resolve the issue as soon as possible, since driving the engine under abnormal conditions for a long period of time can cause internal engine damage. The best description for the seriousness of this code would be a minor problem that can get much worse if it is ignored for a long period of time.

What repairs can fix the P0066 code?

Repairs that can fix the P0066 code would include:

Additional comments regarding the P0066 code

If any of the system wiring is damaged, the most inexpensive way to resolve the issue would be to wrap electrical tape around the damaged portion of the wire as opposed to replacing the entire air assisted injector circuit wiring harness. Also, even if the vacuum lines are not the cause of this code to be set in the powertrain control module, it is a good idea to go ahead and replace them in the process of servicing this system as a preventative maintenance service.

Need help with a P0066 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
P0066

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

SCHEDULE P0066 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

Mack

19 years of experience
92 reviews
Mack
19 years of experience
On time. Very knowledgeable. Great guy! Will not hesitate to use him again and will recommend him to everyone. Knows his stuff!
2012 MITSUBISHI LANCER - CHECK ENGINE LIGHT IS ON - MANSFIELD, TEXAS

James

28 years of experience
364 reviews
James
28 years of experience
Very knowledgable and professional.
1997 MITSUBISHI MONTERO - CHECK ENGINE LIGHT IS ON - BUENA PARK, CALIFORNIA

Chris

19 years of experience
1240 reviews
Chris
19 years of experience
Chris was very knowledgeable and was able to find the problem right away. This guy knows his stuff!
2008 NISSAN ALTIMA - CHECK ENGINE LIGHT IS ON - LAKE FOREST, CALIFORNIA

Robert

30 years of experience
75 reviews
Robert
30 years of experience
Thanks for double checking my quote.
1996 TOYOTA AVALON - CHECK ENGINE LIGHT IS ON - ATLANTA, GEORGIA

More related articles

P2422 OBD-II Trouble Code: Evaporative Emissions Control System (EVAP) Vent Valve Stuck Closed
Diagnostic Trouble Code (DTC): P2422 P2422 code definition Evaporative Emissions Control System (EVAP)...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...
Auto Safety Tips
Driving is more than a way to get from point A to point B. Owning and driving a car can also be a highly enjoyable experience. Whether a person is driving...

Related questions

Q: Check Engine light; upstream O2 sensor

Hi there. If you have a code for the upstream O2 sensor then that is the most likely problem. Knowing the code would help me to be able to tell for sure what is going on. If you replaced the...

Q: C121C torque request signal denied and P0334 Cam shaft sensor

The cam sensor code (actually P0344), is known problem, and there is a Technical Service Bulletin (232460) that addresses this fault and repair. Check with your Dodge dealer to understand what the TSB covers or not. The C121C code has...

Q: Check Engine light on; transmission leak

The coolant temperature sensor is likely what caused your Check Engine light. Sometimes aftermarket manufacturers produce parts of a lesser quality than the OEM. However, this does not mean that all aftermarket manufacturers produce faulty parts. It is harder to...

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