Shift solenoid - 2001 Lincoln Town Car

1700 is a generic code for many makes and models referring to a transmission issue.1751 is directed to the shift solenoid valve b. May be able to replace just that solenoid and be ok. Cheaper than a transmission.

Something wrong with the shift lock system maybe. Safety system that won't allow the gear selector to move from park unless the driver is pushing the brake pedal . Do your brake light's work ? Does your caddy have floor or column shift ?
Automatic Transmission Shift Lock Control Description and Operation (Floor Shift)
The automatic transmission shift lock control system is a safety device that prevents an inadvertent shift out of PARK when the engine is running. The driver must press the brake pedal before moving the shift lever out of the PARK position. The system consists of the following components:
• The automatic transmission shift lock solenoid (serviced as the automatic transmission shift lock actuator), as well as the body control module (BCM) and the engine control module (ECM).The shift lock solenoid is located within the floor shift control assembly with vehicles equipped with floor shift.
• The BCM controls the voltage supply circuit of the shift lock control solenoid. The following conditions must be before the BCM will supply voltage to the shift lock control solenoid.
The BCM controls the voltage to the shift lock control solenoid through the shift lock control solenoid controlled voltage circuit. The following conditions must be met before the BCM will supply voltage to the shift lock solenoid:
• The ignition is in the ON position.
• The ECM sends an input via GMLAN serial data to the BCM indicating the transmission is in the PARK position.
• The BCM determines the brake pedal is applied according the brake pedal position.
Since the shift lock control solenoid is permanently grounded, the BCM supplies voltage to the automatic transmission shift lock control solenoid, mechanically unlocking the shift lever allowing the driver to move the shift lever out of the PARK position as the solenoid energizes. When the brake pedal is not applied, the BCM turns the control voltage output of the shift lock control solenoid OFF, de-energizing the shift lock control solenoid. The de-energized solenoid mechanically locks the shift lever in the PARK position.
During remote start operation, the BCM will de-energize the shift lock control circuit, locking the shift lever in the PARK position.

There is no module on the brake pedal . There is a brake switch , do the brake lights work ? If the brake lights work switch is ok .
Automatic Transmission Shift Lock Control Description and Operation
The automatic transmission shift lock control system is a safety device that prevents an inadvertent shift out of PARK when the engine is running. The driver must press the brake pedal before moving the shift lever out of the PARK position. The system consists of the following components:
• The automatic transmission shift lock solenoid (serviced as the automatic transmission shift lock actuator), as well as the body control module (BCM) and the engine control module (ECM). The shift lock solenoid is located within the floor shift control assembly with vehicles equipped with floor shift.
• The body control module (BCM) controls the voltage supply circuit of the shift lock control solenoid. The following conditions must be before the BCM will supply voltage to the shift lock control solenoid.
The BCM controls the voltage to the shift lock control solenoid through the shift lock control solenoid controlled voltage circuit. The following conditions must be met before the BCM will supply voltage to the shift lock solenoid:
• The ignition is in the ON position.
• The engine control module (ECM) sends an input via GMLAN serial data to the BCM indicating the transmission is in the PARK position.
• The BCM determines the brake pedal is applied according the brake pedal position.
Since the shift lock control solenoid is permanently grounded, the BCM supplies voltage to the automatic transmission shift lock control solenoid, mechanically unlocking the shift lever allowing the driver to move the shift lever out of the PARK position as the solenoid energizes. When the brake pedal is not applied, the BCM turns the control voltage output of the shift lock control solenoid OFF, de-energizing the shift lock control solenoid. The de-energized solenoid mechanically locks the shift lever in the PARK position.
During remote start operation, the BCM will de-energize the shift lock control circuit, locking the shift lever in the PARK position.

Your best bet ,have it towed to a qualified repair shop !

Automatic Transmission Shift Lock Control Description and Operation.
The automatic transmission shift lock control system is a safety device that prevents an inadvertent shift out of PARK when the engine is running. The driver must press the brake pedal before moving the shift lever out of the PARK position. The system consists of the following components:
• The automatic transmission shift lock solenoid (serviced as the automatic transmission shift lock actuator), as well as the body control module (BCM) and the engine control module (ECM). The shift lock solenoid is located within the floor shift control assembly with vehicles equipped with floor shift.
• The BCM controls the voltage supply circuit of the shift lock control solenoid. The following conditions must be met before the BCM will supply voltage to the shift lock control solenoid.
The BCM controls the voltage to the shift lock control solenoid through the shift lock control solenoid controlled voltage circuit. The following conditions must be met before the BCM will supply voltage to the shift lock solenoid:
• The ignition is in the ON position.
• The ECM sends an input via GMLAN serial data to the BCM indicating the transmission is in the PARK position.
• The BCM determines the brake pedal is applied according the brake pedal position.
Since the shift lock control solenoid is permanently grounded, the BCM supplies voltage to the automatic transmission shift lock control solenoid, mechanically unlocking the shift lever allowing the driver to move the shift lever out of the PARK position as the solenoid energizes. When the brake pedal is not applied, the BCM turns the control voltage output of the shift lock control solenoid OFF, de-energizing the shift lock control solenoid. The de-energized solenoid mechanically locks the shift lever in the PARK position.
During remote start operation, the BCM will de-energize the shift lock control circuit, locking the shift lever in the PARK position.
Circuit/System Description
The body control module (BCM) controls the shift lock solenoid by providing battery voltage to the shift lock control solenoid. The BCM utilizes a smart driver to control the voltage supplied to the shift lock solenoid. The smart driver monitors the voltage and current flow of the control circuit.
Diagnostic Aids
• Use a scan tool to verify there are no brake pedal position sensor and/or transmission internal mode switch (IMS) DTCs set that could cause the BCM not to provide battery voltage to the A/T shift lock solenoid.
• If the automatic transmission shift lock control circuit is shorted to battery positive voltage, the A/T shift lock solenoid will be inoperative. The vehicle will shift out of PARK without depressing the brake pedal.
Your best bet is have it towed to a repair shop !

The automatic transmission shift lock control system is a safety device that prevents an inadvertent shift out of PARK when the engine is running. The driver must press the brake pedal before moving the shift lever out of the PARK position. The system consists of the following components:
?€¢
The automatic transmission shift lock control solenoid

?€¢
The body control module (BCM)

?€¢
The powertrain control module (PCM) or the transmission control module (TCM).

The BCM controls the voltage to the shift lock control solenoid through the shift lock control solenoid controlled voltage circuit. The following conditions must be met before the BCM will supply voltage to the shift lock solenoid:
?€¢
The ignition is in the ON position.

?€¢
The PCM / TCM sends an input to the BCM indicating the transmission is in the PARK position.

?€¢
The BCM determines the brake pedal is not applied according the brake pedal position.

Since the shift lock control solenoid is permanently grounded, the BCM supplies voltage to the automatic transmission shift lock control solenoid, mechanically locking the shift lever in the PARK position as the solenoid energizes. When the brake pedal is applied, the BCM turns the control voltage output of the shift lock control solenoid OFF, de-energizing the shift lock control solenoid. The de-energized solenoid releases the mechanical lock allowing the driver to move the shift lever out of the PARK position. When the transmission is out of the PARK position, the shift lock control solenoid remains de-energized.
The body control module (BCM) controls the A/T shift lock control solenoid by providing battery voltage to the A/T shift lock control solenoid. The BCM utilizes a smart driver to control the voltage supplied to the A/T shift lock control solenoid. The smart driver monitors the voltage and current flow of the control circuit.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC B2705 Gearshift Unlock Circuit
You could have a bad brake light switch , automatic transmission shift lock control solenoid.
the BCM or wiring problem
Install a scan tool. Turn ON the ignition, with the engine OFF. Press and release the brake pedal several times while observing the BTSI solenoid parameter in the body control module (BCM) output data list

Have you check fluid level ? Is your check engine light on ? You have a bad shift solenoid inside the transmission ,more then likely . Have codes checked ,you mite have P0700 + code

P0750 - Shift Solenoid A

P0751 - Shift Solenoid A Performance or Stuck Off

P0752 - Shift Solenoid A Stuck On

P0753 - Shift Solenoid A Electrical

P0754 - 1-2 Shift Solenoid Intermittent

P0755 - Shift Solenoid B

P0756 - Shift Solenoid B Performance or Stuck Off

P0757 - Shift Solenoid B Stuck On

P0758 - Shift Solenoid B Electrical

P0761 - Shift Solenoid C Performance or Stuck Off

1/2 shift solenoid, 2/3 shift solenoid, and 3/2 shift solenoid
there is 3 shift solenoid and tcc solenoid , pwm solenoid, and force motor , that's it
hope it helps

Shift Solenoid B Control Circuit High

Areas to check:

• Short in shift solenoid valve No. 2 circuit
• Shift solenoid valve No. 2
• ECM

• Check the shift solenoid valve No. 2 when DTC P0976 and P0977 is output.
• Check harness and connector between ECM and shift solenoid valve No. 1 or No. 2.
  

To check the Shift Solenoid Valve No. 2:

1. Jack up the vehicle.
2. Remove the oil pan.
3. Remove the shift solenoid valve No. 1 or No. 2.
   

CHECK:

1. Measure the resistance between the solenoid connector terminal and the body ground. Standard: 11 - 15 W at 20°C (68°F)
2. Connect the battery positive lead to the solenoid connector terminal and the battery negative lead to the solenoid body ground. Standard: Solenoid operation noise is produced. If not, Replace solenoid valve. If the Solenoid operation noise is produced, Check and replace the ECM.
   

I’m happy to help further over the phone at https://www.6ya.com/expert/jeremy_69f3cc28d95bf514

Definition of Diagnostic Trouble Code P1714 Chrysler: Low Battery Voltage Dodge: Low Battery Voltage Ford: Shift Solenoid A Inductive Signature Jaguar: Shift solenoid A inductive signature malfunction Jeep: Low Battery Voltage Lincoln: Shift Solenoid A Inductive Signature Mazda: Shift Solenoid '1' Mechanical Fault Mercury: Shift Solenoid A Inductive Signature Subaru: Throttle position sensor power circuit for automatic transmission
Definition of Diagnostic Trouble Code P1714 Chrysler: Low Battery Voltage Dodge: Low Battery Voltage Ford: Shift Solenoid A Inductive Signature Jaguar: Shift solenoid A inductive signature malfunction Jeep: Low Battery Voltage Lincoln: Shift Solenoid A Inductive Signature Mazda: Shift Solenoid '1' Mechanical Fault Mercury: Shift Solenoid A Inductive Signature Subaru: Throttle position sensor power circuit for automatic transmission
Definition of Diagnostic Trouble Code P1714 Chrysler: Low Battery Voltage Dodge: Low Battery Voltage Ford: Shift Solenoid A Inductive Signature Jaguar: Shift solenoid A inductive signature malfunction Jeep: Low Battery Voltage Lincoln: Shift Solenoid A Inductive Signature Mazda: Shift Solenoid '1' Mechanical Fault Mercury: Shift Solenoid A Inductive Signature Subaru: Throttle position sensor power circuit for automatic transmission
That code is low battery voltage on a chrysler

What was the codes exactly that Auto Zone gave you.??? it might just be a simple wire harness that may have gone loose since you did some work on the speed sensor.
Here are the trouble codes for your car.  Good Luck and get the car scanned again for a more define information.

P0751 Shift Solenoid A Performance or Stuck Off

P0752 Shift Solenoid A Stuck On

P0753 Shift Solenoid A Electrical

P0754 Shift Solenoid A Intermittent

P0755 Shift Solenoid B Malfunction

P0756 Shift Solenoid B Performance or Stuck Off

P0757 Shift Solenoid B Stuck On

P0758 Shift Solenoid B Electrical

P0759 Shift Solenoid B Intermittent

P0760 Shift Solenoid C Malfunction

P0761 Shift Solenoid C Performance or Stuck Off

P0762 Shift Solenoid C Stuck On

P0763 Shift Solenoid C Electrical

P0764 Shift Solenoid C Intermittent

P0765 Shift Solenoid D Malfunction

P0766 Shift Solenoid D Performance or Stuck Off

P0767 Shift Solenoid D Stuck On

P0768 Shift Solenoid D Electrical

P0769 Shift Solenoid D Intermittent

P0770 Shift Solenoid E Malfunction

P0771 Shift Solenoid E Performance or Stuck Off

P0772 Shift Solenoid E Stuck On

P0773 Shift Solenoid E Electrical

P0774 Shift Solenoid E Intermittent

P0780 Shift Malfunction