Error Code P1693 is defined as Transponder No Response Error/Invalid Response, meaning the TP has an invalid transporter data.
This error code is a manufacturer-specific trouble code, meaning it does not apply to all vehicles makes. Rather, it applies only to specific vehicle makes, such as Chrysler/Dodge/Jeep, Citroen/Peugeot, Ford, GM, Mercedes, Mini, Plymouth, Porsche, Saab, Saturn, Toyota, Volkswagen/Audi, and Volvo. Specification on the definition, troubleshooting, and repairs still vary from one make and model to another.
Throughout key teaching procedure, the transponder will be programmed along with the vehicle specific data. The specific data for the vehicle is written into the transponder’s memory. This write procedure will be unique; therefore, the content of the transponder can’t be modified or changed. The data is a string of 9-bytes defined by the manufacturer of the vehicle.
The memory of the transponder is split into two parts; the authenticator and the key password after this programming the transponder memory is locked, and the data (PIN code) can’t be read or changed respectively. The status of the transponder changes from “virgin” to “learned.” Moreover, every transponder includes a unique Identified Number (IDE) of 32bit. These too will be unique, meaning every IDE will be different from each other. IDE is programmed by the manufacturer and saved as a read-only value. Both the key password and the authenticator will not be transferred from the PCM (powertrain control module, also known as ECM or engine control module) to the transponder or vice versa. Only the results from the encryption algorithm will be transferred. It is almost impossible to calculate the specific data of the vehicle from the results of the encryption. For the teaching of keys and special purposes, the PCM is connected to the tester device.
When the ignition engine is turned on, the coil will supply energy to the transponder, which in turn accumulates energy in the condenser. When the energy supply from the coil is stopped, using the stored energy in the condenser, the transponder transmits the ID CODE (stored within the ASIC).
As with other error codes, this code activates the Check Engine light and registers the code to the system. For most makes, this code is an immobilizer code, which means the vehicle will not start.
If the engine is turned On using an unregistered key, or no key signal is detected (burglary), the immobilizer module will transmit “engine On prohibiting” order to the PCM, which will eventually disable the injector operation, keeping the vehicle from starting.
Also, in many cases, this code is caused by a fault in the IP.
How to Check
As said earlier, Error Code P1693 is set when recognized transponder data is different from the data inputted in ECM. For diagnosis and repairs, check the immobilizer system DTC guide for more detailed information.
Obviously, you can call your dealer for help to get this error code fixed.
Different make and different models will its unique diagnosis and repairs.