P0904 OBD-II Trouble Code: Gate Select Position Circuit [senses left / right position]

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

SCHEDULE P0904 DIAGNOSTIC Get a fair and transparent estimate upfront
Red-stars EXCELLENT RATING ON

Cost of diagnosing the P0904 code

P0904 is a diagnostic trouble code (DTC) for "Gate Select Position Circuit [senses left / right position]". 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 P0904 DIAGNOSTIC Get a fair and transparent estimate upfront

P0904 code definition

The P0904 code indicates that the electronic control module, or ECM, has detected a problem with the gate select position censor circuit. This code may also be accompanied by the P0905, P0906, P0907, or P0908 codes.

What the P0904 code means

In most vehicles manufactured today, the TCM and ECM use various sensors to monitor and control the performance of the transmission. One of those sensors is the gate select position sensor, which tells the TCM and ECM what gear position the driver has put the vehicle in. These sensors are also used to monitor brake slippage and to detect clutch application in a manual vehicle. If the ECM is not receiving the correct signal from this sensor, it will register the P0904 code.

What causes the P0904 code?

Most often, bad electrical connections within the circuit are to blame. This may include corroded or damaged wire harnesses, or loose connections. However, a misaligned sensor can also cause this issue. As a last resort, a faulty sensor may be suspected as the cause of the P0904 code.

What are the symptoms of the P0904 code?

Before the P0904 code is detected, the cruise control will usually stop working. In most cases, the Check Engine light will activate within two to three drive cycles after the PCM has detected the issue.

How does a mechanic diagnose the P0904 code?

After an OBD-II scanner detects the P0904 code, a technician should begin by checking the alignment of the sensor. After a transmission repair, it is common for sensors to be misaligned. They may need to be rotated to a neutral baseline in order for the gate select position to be properly detected.

After this repair is performed, the mechanic should clear the code and retest the system. If the code reappears, they should then check all electrical components, looking for any loose, corroded, damaged, or otherwise faulty wiring or connectors. These should be replaced and then the system should be cleared and checked again.

If neither of these repairs gives the correct diagnosis, then the sensor is probably faulty.

Common mistakes when diagnosing the P0904 code

When diagnosing the underlying cause of the P0904 code, the most common mistake is forgetting to disconnect the PCM and the cruise control module when testing circuit resistance. It is also important to clear the code and do a road test after each potential solution is attempted. If the most common repairs do not stop the Check Engine light from reappearing, it can be a sign of an intermittent issue that requires an in-depth inspection and servicing.

How serious is the P0904 code?

If the P0904 code is being detected, a vehicle should be repaired immediately. Without the ability to properly detect the gear, the vehicle can become unsafe to drive, or may become inoperable.

What repairs can fix the P0904 code?

Repairs to address the P0904 code include:

  • Realign any sensors that were not in the correct position.
  • Replace or repair any electrical components that were not operating correctly.
  • Replace a faulty sensor.

Need help with a P0904 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 1-800-701-6220.

P0904
trouble codes
Check Engine Light

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

SCHEDULE P0904 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

4.8/5

Number of Reviews

4,829

Rating Summary
4,442
187
48
28
124
4,442
187
48
28
124

Walter

44 years of experience
64 reviews
Walter
44 years of experience
Jeep Grand Cherokee - Check Engine Light is on - Tulsa, Oklahoma
Went above and beyond my expectations, as i was very nervous about this type of service! But to my surprise, I am absolutely satisfied with the service ! Would recommend 100X to all i know! Thanks for the care and information and time you put in to my qoute and truck@

Keith

16 years of experience
279 reviews
Keith
16 years of experience
BMW 535i xDrive - Check Engine Light is on - Kissimmee, Florida
Very personable, knowledgeable person, who provided information on my car that I was not aware of. The overall experience was great and I would definitely refer this company to my family and friends.

Luis

13 years of experience
20 reviews
Luis
13 years of experience
Audi A3 - Check Engine Light is on - Van Nuys, California
Luis was awesome. Very knowledgeable and a down to earth person. Would highly recommend and plan on using him in the future for any repair that I need!

Joel

19 years of experience
742 reviews
Joel
19 years of experience
Acura RL - Check Engine Light is on - Jacksonville, Florida
very knowledgeable and precise. able to fix electrical issues in my car. Right on time for the appointment.

More related articles

Related questions

2009 chevy cobalt check engine light an low fuel and power sterring

You have several issues but to prioritize, you should have the check engine light issue(s) investigated and resolved first. Following that, if there is a power steering malfunction, that would be addressed and finally if you have a faulty gauge...

Locked brakes - 2004 Cadillac CTS

Hi there. From the description you have provided, your vehicle's left front and right rear caliper locking would have been a combination/proportioning valve before ABS (anti-lock brake system). The EBCM (electronic brake control module) controls the valves in the hydraulic...

Egr solenoid

Hi there. Once these parts are replaced you need to do the test procedure with the same plug otherwise the light will remain on. If you did the reset then the circuit will need to be tested. It can also...

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