P1104 OBD-II Trouble Code: Mass Airflow Sensor Ground Malfunction

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

Red-stars EXCELLENT RATING ON

Cost of diagnosing the P1104 code

P1104 is a diagnostic trouble code (DTC) for "Mass Airflow Sensor Ground 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. Once we are able to diagnose the problem, you will be provided with an upfront quote for the recommended fix and receive $20.00 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$20.00
Toyota$20.00
BMW$20.00
SCHEDULE P1104 DIAGNOSTIC Get a fair and transparent estimate upfront

P1104 code definition

A vehicle Powertrain Control Module (PCM) can store a P1104 trouble code when the system encounters an erratic voltage signal from the Mass Air Flow (MAF) circuit. In addition to a P1104 trouble code, other codes that are commonly stored in conjunction with the code include a P1100, P1101, P1102, and P1103 code.

What the P1104 code means

A P1104 trouble code means that the MAF sensor is sending an erratic voltage to the PCM. This erratic behavior results in the storage of a P1104 trouble and the illumination of the check engine light.

What causes the P1104 code?

The causes of a P1104 trouble code can range from a bad MAF sensor, a short within the MAF sensor wiring harness, or simply a loose connection at the MAF sensor. Some other causes of this problem include a dirty or clogged air filter that reduces flow of air to the MAF sensor, the vane of the MAF contaminated with debris, a leak in the vehicle's vacuum system either before or after the MAF sensor, and a faulty PCM.

What are the symptoms of the P1104 code?

Some common symptoms of a P1104 trouble code includes erratic operation by the engine, a high idle, backfiring by the engine, and reduced engine power when accelerating. The conditions that lead to the storage of this code can also cause internal engine damage if left untreated.

How does a mechanic diagnose the P1104 code?

When diagnosing a P1104 trouble code, a mechanic needs an OBD-II code scanner, a digital volt/ohm meter, and an evaporative smoke tester. The mechanic must also take the following steps:

  • Examine the wiring, connectors, and components of the MAF sensor wiring harness, paying particular attention to any damaged or faulty wiring, connectors, or components. In addition, the mechanic should look for any loose wiring or connectors.
  • Inspect the air filter to see if it needs replacing. While the air filter is removed, the mechanic should inspect and clean the MAF sensor.
  • The mechanic should also clean the MAF sensor vane of any debris or moisture.
  • Next, the mechanic should clear the code and test the system to see if it returns.
  • If the code returns, download any stored codes and the freeze frame data from the PCM to help in further vehicle diagnosis.
  • Perform a smoke test using an evaporative smoke tester, looking for leaks around the MAF sensor.
  • Clear the code once again and retest the system to see if it returns.
  • If the code returns, the mechanic should use a digital volt/ohm meter to test the voltage and ground signal of the MAF sensor.
  • On a failure to find a ground signal or voltage from the MAF sensor, the mechanic should disconnect the PCM and other related modules and test the continuity of the sensor with the battery ground.
  • If the MAF sensor tests as good, test the continuity between the PCM and MAF sensor.
  • Clear the code after making the necessary repairs and retest the system to see if it returns again.

Common mistakes when diagnosing the P1104 code

Mechanics treating a P1104 trouble code commonly make the mistake of replacing the MAF sensor without checking the wiring for fault, damage, or looseness beforehand, which turns out to be the problem. The result is that the repair does not fix the problem and the code returns upon clearing. In addition, mechanics should replace a dirty air filter and clean the MAF sensor before attempting part replacement.

How serious is the P1104 code?

While the problems associated with a P1104 trouble code usually do not prevent the vehicle from operating, the resulting reduction in vehicle performance can lead to difficulty when operating the vehicle. In addition, the possible damage to internal engine components means you should have this trouble code diagnosed and fixed as soon as possible.

What repairs can fix the P1104 code?

To successfully repair a P1104 trouble code, the mechanic should perform the following:

  • Replace any faulty or damaged, wiring, connectors, or components in the MAF sensor wiring harness. The mechanic should also make sure all connections are tight before proceeding.
  • Replace the air filter if it is dirty.
  • Clean the MAF sensor with a CRC 05110 spray cleaner. The mechanic needs to allow the sensor to dry completely before replacing. In addition, the mechanic should take care when removing the sensor, so as to not damage the wiring.
  • Repair any leaks detected by the smoke test in the vacuum system.
  • Replace the MAF sensor if it ultimately proves to be bad.
  • Replace the PCM if the problem lies there. The mechanic also needs to program any new PCM they install.

Need help with a P1104 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
OBD-II
P1104

No more waiting rooms! Our mechanics will come to you to diagnose and fix the P1104 code.

SCHEDULE P1104 DIAGNOSTIC
Get a $20 credit for the follow-up repair

Recent Check Engine Light is on Inspection reviews

Excellent Rating

(6,144)

Rating Summary
5,685
221
51
35
152
5,685
221
51
35
152

Chris

11 years of experience
13 reviews
Chris
11 years of experience
Ford F-150 - Check Engine Light is on - North Salt Lake, Utah
We were having problems with our check engine light, and Chris was exceptionally thorough until he found the problem and could help resolve the situation. We appreciate having someone who cares enough to get the job done right, not just done. We will definitely use Chris' services in the future. Thanks Chris.

Leng

21 years of experience
2 reviews
Leng
21 years of experience
Mazda MPV - Check Engine Light is on - Seattle, Washington
Leng arrived on time and explained the issue that my van is having. I will make a follow up appointment for the fix. Friendly, easy to talk to, and professional - thank you very much!

Okela

13 years of experience
11 reviews
Okela
13 years of experience
Land Rover LR4 - Check Engine Light is on - Brooklyn, New York
Okela was incredible! He is super thorough and took time to walk us through the issues with our LR4. Couldn’t recommend more! Thank you Okela!!

Robert

37 years of experience
188 reviews
Robert
37 years of experience
Land Rover LR2 - Check Engine Light is on - Atlanta, Georgia
Robert arrived on time. Did a diagnostic check quickly. He was friendly, and gave great service. He knows how to work on a Land Rover.


More related articles

P2234 OBD-II Trouble Code: O2 Sensor Signal Circuit Shorted to Heater Circuit Bank 2 Sensor 1
P2234 P2234 code definition O2 Sensor Signal Circuit Shorted to Heater Circuit Bank 2 Sensor 1 What the P2234 code means Code P2234 is an OBD-II generic code for the Engine Control Module (ECM) detecting the O2 sensor signal wire...
P0770 OBD-II Trouble Code: Shift Solenoid E Malfunction
P0770 means there is a malfunction of shift solenoid E on the transmission valve body, likely due to a faulty shift solenoid or issue with the fluid.
P0096 OBD-II Trouble Code: Intake Air Temperature Sensor 2 Circuit Range/Performance
P0096 P0096 code definition Intake Air Temperature Sensor 2 Circuit Range/Performance What the P0096 code means P0096 is the OBD-II generic code indicating that the engine control module (ECM) has determined that the intake air temperature sensor 2 (IAT2)...

Related questions

check engine light is on

A fault code p0304 is typically caused by a faulty plug or a failed ignition coil. If it has been quite a while since there has been a tune up done, I would start there. Many times a misfire can...

OD2 scanner read trouble code P0101

Your computer may not be able to correctly interpret the data from the mass airflow sensor on your engine causing the P0101 code to keep returning. The manufacturer has a Technical Service Bulletin that came out January 30th of 2015....

Check engine light is illuminated and the car is not starting

Hey there, thanks for writing in. In the future, please include the code number. There are several codes that this system can set. If you have a crank sensor code, this will cause your car to not start. The...

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