AutoCodes – Mercury – P1857 Mercury

P1857 Mercury Code - Transfer Case Contact Plate 'C' Short Circuit To Ground

Quick Answer

The Mode Select Switch (MSS) communicates the operator's choice to the Transfer Case Control Module (TCCM). Common causes include Faulty Transfer Case Control Module (TCCM), Transfer Case Control Module harness is open or shorted, Transfer Case Control Module circuit poor electrical connection. 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: P1857 Mercury indicates Transfer Case Contact Plate 'C' Short Circuit To Ground.
Common causes: Common causes include Faulty Transfer Case Control Module (TCCM), Transfer Case Control Module harness is open or shorted, Transfer Case Control Module circuit poor electrical connection.
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 1,230

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 15, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P1857 Mercury Description

The Mode Select Switch (MSS) communicates the operator's choice to the Transfer Case Control Module (TCCM). As the TCCM commands the gearmotor encoder assembly to 4H mode, the transfer case shift fork moves to engage 4H mode which also engages the dual-cone synchronizers to bring the front driveline to the same speed as the rear driveline. The TCCM also activates the hublock vacuum solenoid, providing a vacuum and engaging the Constant Vacuum Hublock (CVH) at each front wheel. If the vehicle is not responding to the operator's intentions, systematically check the necessary inputs and outputs of the TCCM, components of the transfer case, CVH components, and axle shafts. Check all circuits for opens and shorts to power or ground.

OBDII Code P1857 Mercury - Transfer Case Contact Plate 'C' Short Circuit To Ground - AutoCodes.com — P1857 Mercury Code - Transfer Case Contact Plate 'C' Short Circuit To Ground

What does this mean?

What are the Possible Causes of the DTC P1857 Mercury?

Faulty Transfer Case Control Module (TCCM)
Transfer Case Control Module harness is open or shorted
Transfer Case Control Module circuit poor electrical connection
Faulty Transfer case
Faulty Front axle assembly

How to Fix the DTC P1857 Mercury?

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 P1857 Mercury 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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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 P1857 Mercury Code

1. What are the common symptoms of OBDII code P1857 in a Mercury vehicle?

The common symptoms of OBDII code P1857 in a Mercury vehicle may include issues with the four-wheel-drive system, difficulty shifting gears, and warning lights illuminated on the dashboard.

2. What does the OBDII code P1857 Mercury Transfer Case Contact Plate 'C' Short Circuit To Ground mean?

The code P1857 indicates a short circuit to ground on contact plate 'C' within the transfer case of a Mercury vehicle.

3. What are the possible causes of OBDII code P1857 in a Mercury vehicle?

Possible causes of OBDII code P1857 in a Mercury vehicle include damaged wiring, a faulty contact plate, issues with the transfer case motor, or a poor electrical connection.

4. How can I diagnose OBDII code P1857 in my Mercury vehicle?

Diagnosing OBDII code P1857 involves inspecting the wiring and connections related to the transfer case contact plate 'C', testing the transfer case motor, and using a scan tool to retrieve and clear the fault code.

5. Is it safe to continue driving my Mercury with OBDII code P1857 present?

It is not recommended to drive your Mercury with OBDII code P1857 present, as it can lead to potential issues with the transfer case operation and affect the vehicle's drivability.

6. Can I repair OBDII code P1857 in my Mercury vehicle myself?

Depending on your level of expertise, you may be able to repair OBDII code P1857 in your Mercury vehicle yourself by addressing the wiring, contact plate, or transfer case motor. However, it is recommended to seek professional assistance for accurate diagnosis and repair.

7. How much does it typically cost to fix OBDII code P1857 in a Mercury vehicle?

The cost of fixing OBDII code P1857 in a Mercury vehicle can vary depending on the specific cause of the issue, parts needed for repair, and labor charges. It is advisable to obtain quotes from reputable mechanics or service centers.

8. Is OBDII code P1857 a common problem in Mercury vehicles?

OBDII code P1857 related to the Transfer Case Contact Plate 'C' Short Circuit To Ground is not extremely common in Mercury vehicles, but it can occur due to various factors such as wear and tear, electrical faults, or component failures.

9. Will resetting the fault code make OBDII code P1857 go away permanently?

Resetting the fault code associated with OBDII code P1857 may temporarily clear the warning light, but if the underlying issue causing the fault code is not addressed, it is likely to reappear. It is important to diagnose and fix the root cause of the problem.

10. How urgent is it to address OBDII code P1857 in a Mercury vehicle?

It is recommended to address OBDII code P1857 in a Mercury vehicle promptly to prevent potential damage to the transfer case components and ensure the safe operation of the vehicle. Delaying repairs can lead to more extensive and costly issues in the long run.