AutoCodes – Mercury – P163C Mercury

P163C Mercury Code - Secondary Generator Field Terminal Circuit Low

Quick Answer

With the engine running, the charging system warning indicator is off. Common causes include Faulty Generator (Alternator), Generator harness is open or shorted, Generator 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: P163C Mercury indicates Secondary Generator Field Terminal Circuit Low.
Common causes: Common causes include Faulty Generator (Alternator), Generator harness is open or shorted, Generator 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 818

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 Jan 05, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P163C Mercury Description

With the engine running, the charging system warning indicator is off. The circuit from the battery B+ to the generator regulator is 13-15 volts. This voltage feedback is used by the regulator to maintain the battery voltage at the desired set-point. The S (stator) circuit (internal to the generator) is used to monitor generator operation. This circuit and other regulator internal conditions are checked by the regulator to allow the PCM to turn off the charging system warning indicator by sending a message over the Controller Area Network (CAN) bus to the Instrument Cluster (IC). The positive battery output (B+) circuit is the generator output supplied to the battery and electrical system. For dual generator systems, these circuits are duplicated. Both generator regulators send a signal to the Powertrain Control Module (PCM) to allow the PCM to turn off the charging system warning indicator. In dual generator systems, the PCM keeps the secondary generator in a standby state where it does not generate current unless the primary generator is generating full power and more current is needed to support the vehicle loads. This may make it appear that the secondary generator is not working when vehicle loads are not large. It is important to note that a normal operational state of the charging system is for the secondary generator to not produce current.

OBDII Code P163C Mercury - Secondary Generator Field Terminal Circuit Low - AutoCodes.com — P163C Mercury Code - Secondary Generator Field Terminal Circuit Low

What does this mean?

What are the Possible Causes of the DTC P163C Mercury?

Faulty Generator (Alternator)
Generator harness is open or shorted
Generator circuit poor electrical connection
Faulty Powertrain Control Module (PCM)

How to Fix the DTC P163C 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 P163C 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 P163C Mercury Code

1. What does OBDII code P163C mean for a Mercury vehicle?

P163C indicates a "Secondary Generator Field Terminal Circuit Low," meaning thereâ€™s an issue with the electrical circuit controlling the secondary generator or alternator.

2. What are the common symptoms of code P163C in a Mercury?

Symptoms may include a check engine light, battery warning light, poor charging performance, dim headlights, or difficulty starting the vehicle.

3. What causes the P163C code to appear in Mercury vehicles?

Common causes include a faulty alternator, damaged wiring or connectors in the generator field circuit, or a malfunctioning powertrain control module (PCM).

4. Can a bad battery trigger the P163C code?

While a bad battery itself is unlikely to directly cause P163C, it can contribute to charging system issues that may lead to this code.

5. How do you diagnose the P163C code on a Mercury?

Diagnosis typically involves inspecting the generator field circuit wiring and connectors, testing the alternator, and checking the PCM for proper operation.

6. Can you drive a Mercury with the P163C code active?

Driving with this code is not recommended, as it may result in a drained battery, loss of power, or vehicle stalling.

7. What repairs are needed to fix the P163C code?

Repairs may include replacing the alternator, repairing or replacing damaged wiring, or reprogramming or replacing the PCM if necessary.

8. How much does it cost to fix the P163C code on a Mercury?

The repair costs can vary widely, ranging from $100 for simple wiring repairs to $500â€“$1,000 if the alternator or PCM needs replacement.

9. Can disconnecting the battery clear the P163C code?

Disconnecting the battery may temporarily clear the code, but it wonâ€™t fix the underlying problem, and the code will likely return.

10. How can you prevent the P163C code from occurring again?

Regularly inspect and maintain the charging system, check wiring and connections for wear, and replace components like the alternator or battery as needed.