AutoCodes – Generic – P17D4

P17D4 Code - Transfer Case Neutral Range Detected in High or Low Range

Quick Answer

The Engine Control Module (ECM) uses the following two ways to determine if the transfer case is in 4WD Low, 4WD High, or Neutral. Common causes include Reprogram Engine Control Module (ECM), Faulty Engine Control Module, Engine Control Module harness is open or shorted. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: P17D4 indicates Transfer Case Neutral Range Detected in High or Low Range.
Common causes: Common causes include Reprogram Engine Control Module (ECM), Faulty Engine Control Module, Engine Control Module harness is open or shorted.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

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Code Popularity 2,589

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Aug 29, 2022

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P17D4 Description

The Engine Control Module (ECM) uses the following two ways to determine if the transfer case is in 4WD Low, 4WD High, or Neutral.
1. The first way is to compare the transmission output speed sensor to the transfer case output speed sensor in order to calculate the transfer case range.
2. The second way is to use a LAN message sent by the transfer case shift control module to the ECM.
The ECM uses this message to determine motor torque required and transmission shifting.
The internal fault detection is handled inside the control module. No external circuit diagnosis is involved.
If the first way and second way of determining transfer case range do not match while in 4WD Low, 4WD High or Neutral, then the Diagnostic Trouble Code (DTC) is set.

OBDII Code P17D4 - Transfer Case Neutral Range Detected in High or Low Range - AutoCodes.com — P17D4 Code - Transfer Case Neutral Range Detected in High or Low Range

What does this mean?

What are the Possible Causes of the DTC P17D4?

Reprogram Engine Control Module (ECM)
Faulty Engine Control Module
Engine Control Module harness is open or shorted
Engine Control Module circuit poor electrical connection
Transmission internal mechanical problems

How to Fix the DTC P17D4?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P17D4 code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

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Need Help with the Code?

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Information for Specific Makes

P17D4 Buick — Transfer Case Neutral Range Detected in High or Low Range
P17D4 Cadillac — Transfer Case Neutral Range Detected in High or Low Range
P17D4 Chevrolet — Transfer Case Neutral Range Detected in High or Low Range
P17D4 GMC — Transfer Case Neutral Range Detected in High or Low Range

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P17D4 Code

What does the OBDII code P17D4 mean?

The P17D4 code indicates that the vehicle's transfer case has detected a neutral range while in either high or low range, which is not normal for typical operation.

What symptoms might indicate a P17D4 code?

Common symptoms include the inability to engage or disengage the transfer case properly, unusual noises from the transfer case, and warning lights on the dashboard.

What are the common causes of the P17D4 code?

Common causes include a malfunctioning transfer case control module, faulty transmission range sensor, issues with the transfer case shift motor, or low transmission fluid levels.

How can I diagnose the P17D4 code?

Start by using an OBDII scanner to verify the code and check for any other related codes. Inspect the transfer case components, wiring, and connections, and test the transmission range sensor.

What repairs might be necessary for a P17D4 code?

Repairs can include replacing a faulty transmission range sensor, repairing or replacing the transfer case shift motor, or addressing wiring issues. In some cases, reprogramming the transfer case control module may be needed.

Can I drive my vehicle with a P17D4 code?

It is not advisable to drive your vehicle with a P17D4 code, as it may lead to further damage to the transfer case or transmission if not addressed.

How can I prevent a P17D4 code from occurring?

Regular maintenance, including checking transmission fluid levels and servicing the transfer case, can help prevent issues that lead to the P17D4 code.

Is the P17D4 code specific to certain vehicle makes or models?

While the P17D4 code can occur in various vehicles, it is often found in four-wheel drive or all-wheel drive vehicles that have electronic transfer case controls.

What should I do if I clear the P17D4 code and it comes back?

If the code returns after clearing, it indicates a persistent issue that needs to be diagnosed and repaired. It is best to consult a qualified mechanic for further inspection.