Technical Dualogic problem P1744

[consol]

hi people,
Have problem whit my wife car. She has fiat punto `03 1,2 8v whit automatic gearbox.
Story: car stuck in N gear (Neutral) and cant shifting anymore. i have diagnostic and she say Error P1744 - Hydr. Pressure Sensor Circuit.

in first moment i think, OK sensor is out must take new... but i take one second hand for test only and problem still here

after this i unplugged sensor from the cable and start diagnostic again, and i see i still have pressure in system 50bar ? plug sensor in cable but no install on robot dualogic and again have 50 bar pressure in system. all the time have 50 bar. the problem is some cable may be... but need little help here. where is gearbox ECU and what pin need to check in ecu.
all the time pressure in system move 37bar to 50 bar whit no sensor

 

[Ziggy122]

The auto box aint that common on the punto

When was it last serviced (fluid)?

Ziggy

 

[consol]

before 2 000 km change fluid

 

[consol]

ok today i try some new.
i clear error code whit diagnostic program, move start key to "MAR" and see parameters... interesting but 20-30 sek hydr. pump no start working and pressure in system is 0.0 bar. affter 30 sek open error code P1744 and pressure in system is 37-50 bar. i think this is service mode ?

i read in fiat forum this:
"No shift possible / Gearbox stuck in "N" and blocked
Hydraulic pump defective
Pump relay defective
Gearbox defective (very rarely)"

than i clear all error code,
put start key to OFF
put start key to MAR and see parameters and again pressure is 0.0 bar.
start engine... pressure is 0.0 bar. hydr. pump no working
affter 20-30 sek when start engine have error code P1744 and pressure in system is 50 bar. (service mode ?)

i test cable to hydr. pump whit lamp, have electricity

the question is.... when i put start key to "MAR" Hydraulic pump must be working because no have pressure in system right ?

2-th question: The electric pump is turned on when the pressure drops below 36.5 bars and off when the pressure in the circuit reaches 46 bars right ?

 

[judderbar]

ok today i try some new.
i clear error code whit diagnostic program, move start key to "MAR" and see parameters... interesting but 20-30 sek hydr. pump no start working and pressure in system is 0.0 bar. affter 30 sek open error code P1744 and pressure in system is 37-50 bar. i think this is service mode ?

i read in fiat forum this:
"No shift possible / Gearbox stuck in "N" and blocked
Hydraulic pump defective
Pump relay defective
Gearbox defective (very rarely)"

than i clear all error code,
put start key to OFF
put start key to MAR and see parameters and again pressure is 0.0 bar.
start engine... pressure is 0.0 bar. hydr. pump no working
affter 20-30 sek when start engine have error code P1744 and pressure in system is 50 bar. (service mode ?)

i test cable to hydr. pump whit lamp, have electricity

the question is.... when i put start key to "MAR" Hydraulic pump must be working because no have pressure in system right ?

2-th question: The electric pump is turned on when the pressure drops below 36.5 bars and off when the pressure in the circuit reaches 46 bars right ?

This might help you?

https://www.fiatforum.com/grande-punto-guides/439619-dualogic-troubleshooting-guide.html

 

[consol]

judderbar this is helpful information tnx.

Problem is fix, have defective pump. after repair now working fine.