AutoCodes – RAM – P1603 RAM

P1603 RAM Code - PCM Internal Dual-Port Communication Failure

Quick Answer

With the ignition off, on, and run/start the Powertrain Control Module (PCM) monitors the communication with the Ignition Switch Output circuit. Common causes include Powertrain Control Module (PCM) fused ignition switch circuit, Faulty PCM, PCM 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: P1603 RAM indicates PCM Internal Dual-Port Communication Failure.
Common causes: Common causes include Powertrain Control Module (PCM) fused ignition switch circuit, Faulty PCM, PCM 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 1,725

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 Sep 30, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P1603 RAM Description

With the ignition off, on, and run/start the Powertrain Control Module (PCM) monitors the communication with the Ignition Switch Output circuit. The Diagnostic Trouble Code (DTC) will set when the PCM detects an intermittent open circuit between the PCM connector and the Fused Ignition Switch Output circuit.

OBDII Code P1603 RAM - PCM Internal Dual-Port Communication Failure - AutoCodes.com — P1603 RAM Code - PCM Internal Dual-Port Communication Failure

What does this mean?

What are the Possible Causes of the DTC P1603 RAM?

Powertrain Control Module (PCM) fused ignition switch circuit
Faulty PCM
PCM harness is open or shorted
PCM circuit poor electrical connection

How to Fix the DTC P1603 RAM?

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 P1603 RAM 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 more information on how to fix the P1603 RAM code? Get Access to Factory Service Manuals

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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 P1603 RAM Code

1. What are the common symptoms of OBDII code P1603 (RAM titled PCM Internal Dual-Port Communication Failure)?

The common symptoms of P1603 can include engine stalling, rough idling, trouble starting the vehicle, and the illumination of the check engine light.

2. What are the possible causes of OBDII code P1603?

The code P1603 is typically caused by issues related to the internal communication between the Powertrain Control Module (PCM) and its dual-port memory.

3. How serious is OBDII code P1603?

While the code itself may not pose an immediate threat to the vehicle's safety, ignoring it can lead to performance issues and potential damage to the engine over time.

4. How can I diagnose OBDII code P1603?

Diagnosing P1603 typically involves using a diagnostic scanner to retrieve the code, checking for any related codes, and inspecting the PCM and its connections for any signs of damage or corrosion.

5. What are the repair options for OBDII code P1603?

Repairing P1603 may involve reprogramming the PCM, replacing damaged wiring or connectors, or, in some cases, replacing the PCM itself.

6. Can I drive my vehicle with OBDII code P1603?

It is not recommended to drive the vehicle with an unresolved P1603 code, as it can lead to potential drivability issues and further damage to the engine.

7. How much does it cost to repair OBDII code P1603?

The cost of repairing P1603 can vary depending on the underlying cause, the extent of the damage, and whether any parts need to be replaced. It's advisable to consult a professional mechanic for a more accurate estimate.

8. Can a DIY enthusiast fix OBDII code P1603?

While some aspects of diagnosing and repairing P1603 may be within the realm of a DIY enthusiast, it is recommended to seek the expertise of a qualified mechanic to ensure the issue is properly addressed.

9. Are there any preventative measures to avoid OBDII code P1603?

Regular maintenance, such as keeping the vehicle's electrical system in good condition and promptly addressing any warning lights, can help reduce the chances of encountering code P1603.

10. Is OBDII code P1603 a common issue in certain vehicle makes or models?

P1603 can occur in various vehicle makes and models, but it may be more prevalent in vehicles with PCM communication or internal memory issues.