Internal PCM failure, specifically a fault in the EEPROM or its write-control circuitry.; Low or unstable battery voltage during a write event, causing the PCM to deny the write for protection.; Poor grounds or corroded power connections at the PCM, leading to voltage drops that trigger the denial.; A recent reflash or programming event that was interrupted or improperly completed.; Aftermarket electronic devices wired into the PCM circuit that introduce noise or voltage spikes.; Water intrusion or connector corrosion at the PCM harness, affecting communication and power delivery.

DTC codes / Chrysler codes / P1696

P1696 · ChryslerPCM Failure EEPROM Write Denied

Q: What does code P1696 mean?

PCM Failure EEPROM Write Denied. P1696 on Chrysler vehicles means the Powertrain Control Module (PCM) refused a request to write data to its internal EEPROM, the non-volatile memory that stores learned values and configuration. The PCM detected that the write operation was denied, which points to a memory or internal fault rather than a sensor or wiring problem.

P1696 on Chrysler vehicles means the Powertrain Control Module (PCM) refused a request to write data to its internal EEPROM, the non-volatile memory that stores learned values and configuration. The PCM detected that the write operation was denied, which points to a memory or internal fault rather than a sensor or wiring problem.

SystemPowertrain

Code typeChrysler specific

SeverityMedium

Fix difficultyProfessional

AreaComputer and output circuits

Symptoms you may notice

Illumination of the check engine light, often with no other noticeable symptoms.
Intermittent rough running or stalling if the PCM cannot reliably store adaptive learning values.
Transmission shift quality may degrade as learned shift adaptations are not saved.
The engine may revert to default or limp-home operating strategies after a key cycle.
In some cases, the vehicle may fail to start or restart because critical memory writes are blocked.

Common causes, most likely first

Internal PCM failure, specifically a fault in the EEPROM or its write-control circuitry.
Low or unstable battery voltage during a write event, causing the PCM to deny the write for protection.
Poor grounds or corroded power connections at the PCM, leading to voltage drops that trigger the denial.
A recent reflash or programming event that was interrupted or improperly completed.
Aftermarket electronic devices wired into the PCM circuit that introduce noise or voltage spikes.
Water intrusion or connector corrosion at the PCM harness, affecting communication and power delivery.

How to diagnose and fix it

Verify battery condition and charging system output; load-test the battery and check for loose or corroded terminals.
Inspect the PCM connectors and harness for corrosion, water intrusion, or chafed wires, and clean or repair as needed.
Check all PCM ground points for tightness and resistance, and clean any corroded grounds.
Clear the code and perform a relearn or drive cycle to see if P1696 returns immediately or only under specific conditions.
If the code persists, reflash or reprogram the PCM with the latest Chrysler software using a factory scan tool.
If reprogramming fails or the code returns, replace and program the PCM, then perform any required anti-theft or configuration relearns.

What Most Techs Miss on P1696

A weak battery that still starts the engine can cause P1696 because the PCM denies EEPROM writes when supply voltage drops during cranking or a write cycle.
This code often appears after a failed or interrupted PCM reflash, so always check for recent programming history before condemning the module.
Aftermarket alarms, remote starters, or stereo wiring tapped into the PCM harness can introduce voltage spikes that trigger the write denial.
P1696 does not always mean the PCM is permanently bad; correcting a ground or voltage issue and clearing the code may be all that is needed.
On some Chrysler models, a related communication code such as U0100 or U0140 may be stored alongside P1696, pointing to a shared power or ground fault.

Can I keep driving with P1696?

The vehicle is usually safe to drive to a repair shop, but avoid long trips and heavy load until the fault is diagnosed. If the engine stalls, shifts harshly, or fails to restart, stop driving and have the vehicle towed.

Tools that help

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Guidance is general and written for Chrysler vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.