What Does P1696 Mean?
The PCM has detected an internal failure with its EEPROM (Electrically Erasable Programmable Read-Only Memory) and cannot write data to memory. This prevents the PCM from storing important calibration data, adaptive values, or diagnostic information.
Common Causes
50%
Failed PCM internal EEPROM chip
25%
Corrupted PCM software or calibration
15%
Low or unstable vehicle battery voltage during write operation
10%
PCM power supply circuit issue
Diagnostic Steps
1
Step 1: Test battery voltage and charging system output (should be 13.5-14.5V with engine running)
2
Step 2: Check all PCM power and ground circuits for proper voltage and continuity
3
Step 3: Inspect PCM connectors for corrosion, bent pins, or moisture intrusion
4
Step 4: Attempt PCM reprogramming or reflashing with manufacturer software
5
Step 5: If reprogramming fails or code returns, PCM replacement is required
Estimated Repair Cost
$400 - $1,500
Parts + labor, varies by vehicle and location
The PCM has detected an internal failure with its EEPROM (Electrically Erasable Programmable Read-Only Memory) and cannot write data to memory. This prevents the PCM from storing important calibration data, adaptive values, or diagnostic information.
The most common cause of P1696 (PCM Failure EEPROM Write Denied) is: Failed PCM internal EEPROM chip
Typical repair costs for P1696 range from $400 to $1,500, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Vehicle may run in default/limp mode with reduced performance. Generally safe to drive but PCM cannot learn or store adaptive values, affecting long-term drivability and emissions.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P1696 to identify the root cause.
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Quick Info
Category
Powertrain
System
Engine Control Module
Difficulty
Type
Manufacturer
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