I have code p1629 - 1994 Buick LeSabre

p0504 brake switch A/B
break light switch, fuse or light bulb
p1629 theft deterrent system cranking single

P1629
Theft Deterrent Fuel Enable Signal Not Received
ECM, PCM
DTC P1629 in Theft Deterrent


Does the vehicle start and run ?

P1629 obdII code.
THEFT DETERRENT CRANK SIGNAL MALFUNCTION

Vehicle operation is disabled if incorrect key or starting procedure is used.

Read more at the link below.

P1629 GM Forum Buick Cadillac Chev Olds GMC Pontiac chat

U0140 Chevrolet Lost Communication With Body Control Module P1629 Chevrolet Theft Deterrent Start Enable Signal Not Received http://www.carobdcode.com/u0422-gmc-invalid-data-received-from-body-control-module#.Vva4p8vmqQw

Nir, Check the attached links,instruction and guides, Good luck
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2006 Buick code links explanation.

P0318 OBD II Check Engine Code Rough Road GMC General Motors

U1300 OBD II Engine Code GMC General Motors

P1629 OBD II Check Engine Code GMC General Motors

DTC P0633 : Theft Deterrent Key Not Programmed

When learning the pre-release password, as well as the challenge and response sequence, the engine control module (ECM) is placed in learn mode. DTC P0633 will set automatically as an indicator that the system is in learn mode and not as a fault indicator. Once the password and challenge/response are learned, learn mode will be exited when the engine is successfully started. At this point, the DTC will be cleared. If the ECM does not exit learn mode, P0633 will remain current and indicate a fault.
The "key" referenced in the DTC descriptor does not refer to the vehicle key. In this case, "key" is referring to the challenge response.
DTC P0633 requires a successful engine start to exit the learn procedure and clear the DTC. If an unrelated malfunction exists that causes engine starting to be disabled or otherwise unavailable, learn mode will not exit and DTC P0633 will remain current. In this situation, the cause of the inoperative engine starting must be corrected before diagnosing DTC P0633.
DTC P1629: Theft Deterrent Fuel Enable Signal Not Received
The theft deterrent module (TDM) sends the pre-release password to the engine control module (ECM) via the serial data circuit. The ECM then sends a challenge to the TDM. Both the ECM and TDM perform a calculation on this challenge. If the calculated response from the TDM equals the calculation performed by the ECM, the ECM will allow vehicle starting.
DTC P1629 is an indicator that the challenge response was not received within the required 2 second window. This does not necessarily indicate a fault is present with the TDM or ECM. Factors such as a long engine crank, a delay in the serial data communication, or B-codes set in the TDM will cause DTC P1629 to set. This DTC should not be used as a fault indicator, but rather as a symptom to assist in the diagnosis of these other systems.
Who checked the codes , you -dealer ? You need to have BCM checked for codes B - codes ! you need a up scale diagnostic scan tool for that , dealer Tech -2 !
DTC B3935 57 : Transponder Authentication Error
DTC B3976 46 : Unconfigured Transponder/Vehicle Configuration Not Programmed
DTC B3060 : Unprogrammed Transponder Identification Code Received
DTC B3055: No Transponder Modulation or No Transponder
DTC B3031: Security System Controller In Learn Mode

Code 1629 is for the computer not getting the security signal to allow the engine to start. Usually a problem with the chip in the key or the lock sensor.
Depending on the model and year, it could be that you did not have the new computer flashed to your old one.

P1629 Theft Deterrent System-Cranking Signal

Check the owners manual to reset it.

P1122 is a throttle position sensor code. P1629 is a theft deterrent system code. P1122 will set when the voltage signal from the throttle position sensor drops below 0.1 volts. Normally, the sensor should measure between 1 volt at idle and 4 volts at full throttle. A failed throttle position sensor could easily cause your problem.

As for the theft deterrent system code, with that code set, the car shouldn't start at all (if the code is active). With P1629, the engine computer should refuse to deliver fuel to the engine. This code can be stored for up to 40 warm up cycles before clearing itself, so unless it is currently active, there may not be any need to worry about it.

I would inspect the wiring and connectors leading to the throttle position sensor. If that wiring is good, I would replace the sensor and see where that got me. Give that a try and let us know how things go.

try leaving the key on for 5 to 10 minutes
for the BCM (body control module) to relearn