The P1696 trouble code is a generic powertrain code related to various issues depending on the vehicle make and model. It generally indicates a problem with the Powertrain Control Module (PCM) or Engine Control Module (ECM) communication, specifically related to EEPROM (Electrically Erasable Programmable Read-Only Memory) write operations or immobilizer system malfunctions.
| P1696 Code Meaning | P1696 Code Common Causes |
|---|---|
| PCM Failure EEPROM Write Denied | Faulty PCM/ECM |
| Immobilizer Key Mismatched | Damaged or faulty key transponder |
| CAN Bus Communication Error | Wiring issues in the CAN bus system |
| ABS Pressure Circuit Calibration Not Learned | Uncalibrated brake pressure sensor |
| Security System Malfunction | Faulty security sounder or related components |
PCM Failure EEPROM Write Denied
Symptoms
- Check Engine Light (CEL) illuminated
- Engine performance issues
- Difficulty starting the vehicle
- Unexpected stalling
Technical Explanation
The P1696 code often indicates that the PCM is unable to write data to its EEPROM. This critical memory stores important vehicle parameters and calibration data. When the PCM fails to write to the EEPROM, it can lead to various driveability issues and prevent the engine from operating correctly.
Step-by-step Diagnosis
- Connect an OBD-II scanner to the vehicle’s diagnostic port.
- Retrieve all stored trouble codes and freeze frame data.
- Clear the codes and test drive the vehicle to see if the P1696 code returns.
- If the code persists, check the battery voltage and charging system to ensure proper power supply to the PCM.
- Inspect all related wiring harnesses and connectors for damage, corrosion, or loose connections.
- Use a multimeter to test the continuity of the PCM power and ground circuits.
- If all circuits check out, the PCM itself may be faulty and require replacement or reprogramming.
Solution Methods
- Repair or replace any damaged wiring or connectors.
- Ensure the battery is fully charged and the charging system is functioning correctly.
- Update the PCM software if available.
- If all else fails, replace the PCM with a new or remanufactured unit.
Cost Estimates
- DIY Diagnosis: $0-$50 (OBD-II scanner rental)
- Professional Diagnosis: $75-$150
- PCM Reprogramming: $150-$300
- PCM Replacement: $500-$1500 (depending on vehicle make and model)
Warning: PCM replacement and programming should only be performed by qualified professionals with the proper equipment and software.
Immobilizer Key Mismatched
Symptoms
- Engine cranks but won’t start
- Security light flashing on the dashboard
- Key not recognized by the vehicle
Technical Explanation
Many modern vehicles use an immobilizer system to prevent theft. When the P1696 code is related to an immobilizer issue, it means the key’s transponder chip is not being recognized by the vehicle’s security system. This can be due to a faulty transponder in the key, a problem with the immobilizer antenna around the ignition switch, or a malfunction in the immobilizer control module.
Step-by-step Diagnosis
- Verify that you’re using the correct key for the vehicle.
- Check if the key’s battery (if applicable) needs replacement.
- Inspect the key fob for any physical damage, especially if it has been dropped or exposed to water.
- Use a spare key if available to determine if the problem is key-specific.
- Check the immobilizer antenna around the ignition switch for damage or loose connections.
- Scan for additional trouble codes that might indicate an immobilizer system malfunction.
Solution Methods
- Replace the key fob battery.
- Reprogram the key transponder (may require dealer assistance).
- Replace the damaged key or transponder chip.
- Repair or replace the immobilizer antenna if faulty.
- In some cases, the immobilizer control module may need replacement.
Cost Estimates
- Key Fob Battery Replacement: $5-$20
- Key Reprogramming: $50-$200
- New Key Fob: $100-$400
- Immobilizer Antenna Replacement: $150-$300
- Immobilizer Control Module Replacement: $300-$800
Note: Some vehicles require specialized equipment for key programming, which may only be available at dealerships or specialized locksmiths.
CAN Bus Communication Error
Symptoms
- Multiple warning lights on the dashboard
- Erratic behavior of various vehicle systems
- Loss of certain vehicle functions
Technical Explanation
The Controller Area Network (CAN) bus is a communication system that allows various control modules in the vehicle to communicate with each other. When the P1696 code is related to a CAN bus error, it indicates a breakdown in this communication, often between the PCM and other modules such as the Transmission Control Module (TCM) or Body Control Module (BCM).
Step-by-step Diagnosis
- Perform a full system scan to identify all modules reporting errors.
- Check the battery voltage and charging system to ensure stable power supply to all modules.
- Inspect CAN bus wiring for damage, particularly in areas prone to heat or mechanical stress.
- Use a multimeter to check for proper resistance on the CAN bus lines (typically should be around 60 ohms between CAN High and CAN Low).
- Check for aftermarket accessories that may be interfering with CAN bus communication.
- Use an oscilloscope to analyze CAN bus signals if available.
Solution Methods
- Repair or replace damaged CAN bus wiring.
- Remove any interfering aftermarket accessories.
- Replace faulty control modules that may be disrupting CAN bus communication.
- Update software for relevant control modules.
Cost Estimates
- Professional Diagnosis: $100-$200
- CAN Bus Wiring Repair: $200-$500
- Control Module Replacement: $500-$1500 (varies widely depending on the specific module)
Caution: CAN bus diagnostics and repairs require specialized knowledge and equipment. Improper repairs can lead to widespread vehicle malfunctions.
ABS Pressure Circuit Calibration Not Learned
Symptoms
- ABS warning light illuminated
- Reduced brake performance
- Unexpected ABS activation during normal braking
Technical Explanation
In some vehicles, particularly Hyundai models, the P1696 code can indicate that the ABS pressure circuit calibration has not been learned or has been lost. This calibration is crucial for the proper functioning of the Anti-lock Braking System (ABS) and ensures accurate pressure readings during braking events.
Step-by-step Diagnosis
- Scan for additional ABS-related codes.
- Check the brake fluid level and condition.
- Inspect the ABS sensor wiring and connectors for damage or corrosion.
- Verify that all ABS sensors are functioning correctly.
- Check for any recent brake system repairs or modifications that might have triggered the need for recalibration.
- Use a compatible scan tool to attempt ABS pressure sensor calibration.
Solution Methods
- Perform ABS pressure sensor calibration using a compatible scan tool.
- If calibration fails, check for faulty ABS sensors or pump motor.
- Repair or replace any damaged ABS components.
- In some cases, the ABS control module may need replacement if it’s unable to learn the calibration.
Cost Estimates
- ABS Sensor Replacement: $200-$400 per sensor
- ABS Module Calibration: $100-$200
- ABS Control Module Replacement: $700-$1500
Warning: Proper ABS function is critical for vehicle safety. If you’re unsure about diagnosing or repairing ABS issues, consult a professional mechanic.
Security System Malfunction
Symptoms
- Alarm system activating randomly
- Difficulty starting the vehicle
- Multiple electrical system malfunctions
Technical Explanation
In some cases, particularly in certain Jaguar models, the P1696 code can be triggered by a malfunction in the vehicle’s security system. This can often be traced back to a faulty security sounder or related components, which can cause a cascade of electrical issues affecting multiple vehicle systems.
Step-by-step Diagnosis
- Check all fuses related to the security system and other affected components.
- Inspect the wiring harness for the security system, particularly near the security sounder.
- Test the voltage at the security sounder to ensure it’s receiving proper power.
- Check for any signs of water damage or corrosion in the security system components.
- Scan for additional trouble codes that might provide more insight into the specific malfunction.
Solution Methods
- Replace blown fuses and repair any damaged wiring.
- Disconnect and replace the faulty security sounder if identified as the source of the problem.
- Repair or replace any corroded connectors or components.
- In some cases, the entire security system control module may need replacement.
Cost Estimates
- Fuse Replacement: $5-$20
- Security Sounder Replacement: $100-$300
- Wiring Harness Repair: $200-$500
- Security System Control Module Replacement: $500-$1000
Note: Tampering with vehicle security systems can have unintended consequences. Always consult your vehicle’s manual or a professional before making modifications.
In conclusion, the P1696 code can indicate a variety of issues depending on the vehicle make and model. While some causes like blown fuses or key transponder issues can be relatively simple to fix, others may require more complex diagnostics and repairs. Always start with the basics: check your vehicle’s battery, inspect visible wiring, and use an OBD-II scanner to gather more information. If you’re unsure about any step in the diagnostic or repair process, it’s best to consult with a qualified mechanic or dealership technician to ensure the issue is resolved correctly and safely.
Frequently Asked Questions About P1696
- Can I drive my car with the P1696 code?
It depends on the underlying cause. In some cases, the vehicle may run normally, while in others, it may not start or have severe performance issues. It’s best to diagnose and address the problem promptly to avoid potential damage or safety issues. - How do I clear the P1696 code?
You can clear the code using an OBD-II scanner. However, if the underlying issue isn’t fixed, the code will likely return. Always address the root cause before clearing codes. - Is the P1696 code serious?
The severity varies depending on the cause. It can range from a minor inconvenience to a significant problem affecting vehicle operation and safety. Prompt diagnosis and repair are recommended. - Can a weak battery cause the P1696 code?
Yes, in some cases. A weak battery can cause voltage fluctuations that may interfere with PCM operations or CAN bus communications, potentially triggering the P1696 code. - How much does it typically cost to fix a P1696 code?
Costs can vary widely, from as little as $50 for a simple fix like a fuse replacement to over $1500 for PCM replacement. The average cost for professional diagnosis and repair is typically between $200 and $600. - Can I diagnose the P1696 code at home?
Basic diagnosis can be done at home with an OBD-II scanner. However, pinpointing the exact cause often requires advanced diagnostic tools and expertise, especially for issues related to the PCM or CAN bus system. - Will the P1696 code clear itself?
In rare cases, if the issue was temporary (like a brief voltage spike), the code might clear itself after several drive cycles. However, it’s more likely that the code will persist until the underlying problem is addressed. - How can I prevent the P1696 code from occurring?
Regular maintenance, avoiding electrical system modifications, and promptly addressing any warning lights or unusual vehicle behavior can help prevent issues that lead to the P1696 code. Keep your vehicle’s software up to date and use high-quality replacement parts when repairs are needed.