AutoCodes – Generic – P163C

P163C 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 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 10,313

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

What does this mean?

What are the Possible Causes of the DTC P163C?

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?

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 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.

Need more information about the P163C code?

Need more information on how to fix the P163C code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P163C code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

P163C Buick — Glow Plug Control Module Primary Circuit
P163C Cadillac — Glow Plug Control Module Primary Circuit
P163C Chevrolet — Glow Plug Control Module Primary Circuit
P163C Ford — Secondary Generator Field Terminal Circuit Low
P163C GMC — Glow Plug Control Module Primary Circuit
P163C Lincoln — Secondary Generator Field Terminal Circuit Low
P163C Mercury — Secondary Generator Field Terminal Circuit Low

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 Code

1. What does the OBDII code P163C mean?

P163C indicates that the secondary generator (typically an alternator) has a low voltage or malfunction in its field terminal circuit.

2. What are the common symptoms of code P163C?

Symptoms may include a charging system warning light, battery not charging properly, dimming headlights, or electrical system malfunctions.

3. What causes the P163C code to appear?

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

4. Can a weak battery trigger the P163C code?

Yes, a weak or failing battery can contribute to the code if it affects the alternatorâ€™s performance or creates low voltage conditions.

5. How can I diagnose the P163C code?

Start by inspecting the alternator, field terminal wiring, and connectors for damage or corrosion. Then, test the alternatorâ€™s output and check for blown fuses related to the charging system.

6. What tools are needed to troubleshoot the P163C code?

Youâ€™ll need a multimeter to check voltage, an OBDII scanner to confirm the code, and possibly a wiring diagram for the secondary generator circuit.

7. Is it safe to drive with the P163C code?

Driving with this code is not recommended, as it can lead to battery drain and cause the vehicle to lose power unexpectedly.

8. How do I fix the P163C code?

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

9. Can the P163C code reset itself?

The code may reset temporarily if the issue is intermittent, but the problem will likely persist until the underlying cause is resolved.

10. How much does it cost to fix the P163C code?

Repair costs vary depending on the cause. Replacing an alternator typically costs $300â€“$800, while fixing wiring issues may cost less if minor repairs are needed.