P2774 OBD-II Trouble Code: 4WD Low Switch Circuit High

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

Red-stars EXCELLENT RATING ON

Cost of diagnosing the P2774 code

P2774 is a diagnostic trouble code (DTC) for "4WD Low Switch Circuit High". 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 P2774 DIAGNOSTIC Get a fair and transparent estimate upfront

P2774 code definition

Exclusive to AWD or 4WD vehicles, a P2774 code means the vehicle’s PCM has detected a problem in the low switch circuit for 4WD. A hard code has been registered and the malfunction indicator lamp (MIL) has illuminated. If you ever find a P2774 code in a 2WD vehicle, there could be a programming issue or a defective PCM.

What the P2774 code means

The P2774 code is an indicator of a problem in the actuator switch circuit for 4WD. This 4WD switch controls the actuation of the 4WD system, and changes between gear ratios in the transfer case – 2WD high, 2WD low, neutral, 4WD high and 4WD low.

What causes the P2774 code?

A P2774 code can be caused by an actuator failure or a failed 4WD switch. Other problems can include:

  • Faulty sensors
  • Faulty solenoids
  • Faulty switches
  • Defective wiring harness or connectors

What are the symptoms of the P2774 code?

Symptoms of a P2774 code can include:

  • Illuminated MIL
  • Failure to shift from 2wd to 4wd low or high, or back again
  • Engine stalls while stopped and in gear
  • Harsh shifts
  • Complete transfer case failure

How does a mechanic diagnose the P2774 code?

Many vehicles, especially older models, rely on a combination of engine vacuum and electronics to actuate shifts in the transfer case. Most newer vehicles, on the other hand, use full-electronic systems of sensors and solenoids to shift from low to high range or back again. Other systems are designed with solenoids that lock front hubs into place, with manual levers to allow shifting for the transfer case. Still others (on AWD vehicles) can automatically switch from 2WD to AWD according to road conditions.

Regardless, practically all OBD II equipped vehicles are designed with an electronic transfer case module that interacts with other control modules and enacts transfer case and front differential changes. 4WD switches may vary, but for on-demand systems, the switch is the “on/off” variety and is mounted in the interior, within reach of the driver.

  • Inspect all wiring and connectors, and repair/replace any damaged, shorted, disconnected or corroded wiring, connectors or components if found.

  • After any repairs of wiring, connectors and components (including fuses), retest the system. If everything seems to be in working order, connect a scanner or code reader to the vehicle’s diagnostic port, recording all stored codes and data.

  • Clear codes and operate the vehicle to see if codes return. If not, there may be an intermittent condition which may need to be allowed to worsen again to make an accurate diagnosis.

  • Should the code return right away, find a factory wiring schematic with connector details. Check for battery voltage on the 4WD switch’s input side, using your digital volt/ohmmeter. If no voltage can be found on the switch’s input side, disconnect any related control modules and check for continuity between the input circuit at the clutch position sensor and the system fuse.

  • Repair any open or shorted circuits.

  • If voltage is present on the 4WD switch’s input side, use the scanner to enable the 4WD system and check voltage readings on the switch’s output side.

  • If voltage is present on the input side but not the output side, with 4WD engaged, a faulty 4WD switch could be the culprit. Replace the switch if needed, and retest the system afterward. If voltage is present at the clutch position sensor’s output circuit, check for voltage at the actuator for 4WD.

  • If no voltage is present, check between the switch and PCM for resistance and circuit continuity, and compare your readings to manufacturer’s specs.

  • Repair any shorted or open circuits/connectors that are faulty, and refer to the factory wiring schematic to ensure you don’t miss any circuits. If readings all agree with factory specs, suspect the PCM itself but remember that faulty PCMs are rare.

Common mistakes when diagnosing the P2774 code

Too many times, P2774 codes have been misdiagnosed, resulting in a complete (very expensive) rebuild or replacement of the transfer case, when a proper diagnosis and replacement of a component may well have fixed the problem.

How serious is the P2774 code?

The P2774 code can result in a vehicle that’s completely disabled, stranding a driver by the side of the road.

What repairs can fix the P2774 code?

  • Replacement of the 4WD switch or activator
  • Replacement of failed sensors
  • Replacement of solenoids or switches
  • Overhaul of wiring harness and/or connectors

Additional comments for consideration regarding the P2774 code

As with any repair job, a P2774 code calls for a thorough investigation of possible causes and a factory service guide and wiring schematic as a guide. Be certain to disconnect any related control modules before testing the 4WD switch and circuits.

Need help with a P2774 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
p2774

No more waiting rooms! Our mechanics will come to you to diagnose and fix the P2774 code.

SCHEDULE P2774 DIAGNOSTIC
Get a $20 credit for the follow-up repair

Recent Check Engine Light is on Inspection reviews

Excellent Rating

(6,328)

Rating Summary
5,857
225
52
35
159
5,857
225
52
35
159

Gustavo

17 years of experience
296 reviews
Gustavo
17 years of experience
Toyota Corolla - Check Engine Light is on - New Braunfels, Texas
As always, punctual and professional. He explains the problem thoroughly. I feel confident in his work and knowledge.

Greg

22 years of experience
86 reviews
Greg
22 years of experience
Mazda 3 - Check Engine Light is on - Queen Creek, Arizona
Greg was scheduled for 1:00 but he was able to come earlier and let us know right away. He was very thorough and spent his time going thru the entire car.

Gustavo

17 years of experience
296 reviews
Gustavo
17 years of experience
Lincoln Aviator - Check Engine Light is on - San Antonio, Texas
Made call before appt. -courteous-knowledgeable-got part need & did prompt repair after computer check.

Claud

8 years of experience
325 reviews
Claud
8 years of experience
Chevrolet Trax - Check Engine Light is on - Grosse Pointe, Michigan
Very good experience. He arrived on time. Explained what he was going to do. Completed the work and was thorough in what I needed for my next service in plain language vs car jargon. I'm a raving fan of Claud!


More related articles

P0243 OBD-II Trouble Code: Turbocharger Wastegate Solenoid A Malfunction
P0243 code definition Turbocharger Wastegate Solenoid A Malfunction What the P0243 code means P0243 is a generic OBD-II code indicating that the...
P0295 OBD-II Trouble Code: Cylinder 12 Injector Circuit High
P0295 P0295 Code Definition Cylinder 12 Injector Circuit High What the P0295 code means The P0295 trouble code means that the Engine Control Module (ECM) detects resistance in the cylinder 12 fuel injector circuit as falling outside the normal range...
P2506 OBD-II Trouble Code: ECM/PCM Power Input Signal Range/Performance
P2506 P2506 code definition ECM/PCM Power Input Signal Range/Performance What the P2506 code means P2506 is an OBD-II generic code for the Engine Control Module (ECM) detecting if the power input signal is not within range or when its performance...

Related questions

Can I continue to drive my car until I get the ignition coil fixed?

Hello Since the ignition coil is the component responsible for generating the engine spark, any problems with it can quickly lead to engine performance issues. Because of this fact, it's not really a good idea to drive the vehicle any...

P1743

This code is for a transmission overdrive solenoid problem. The overdrive solenoid would need to be tested to see if it has the proper resistance of 10 to 20 ohms. If it is okay then the harness will need to...

Unplugged wires ECM DTC

Hello. It is a common issue for the ABS control module to go bad on these trucks. Either the modules are ridiculously expensive or they just aren't available anymore. That is why the connector was unplugged. That is the "cheap"...

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