Feb 102015
 

The gearbox check control unit diagnosis, after ascertaining a fault takes action regarding the down-grade functioning. This data is indicated referring to the faulty component, in the table below:

FAULTY COMPONENT Fault warning light DOWN GRADING
Gear engagement solenoid valves (proportional) On Gear shift acceptance locked, gear engagement excluding idle (N) (vehicle stationary)
Gear selection solenoid valve (ON/OFF) On Gear shift acceptance locked, gear engagement excluding idle (vehicle stationary)
Engagement and selection position sensors On Long time for gear shift.
Rev sensors: engine, gear input and gear output (car speed) On Gear shift acceptance limited to 1, 2, R, N
Oil pressure sensor On Electric pump control in open-loop
Gear request lever switches On Switching in automatic mode “CITY”, cannot engage R
Buttons on steering wheel switches On Does not accept commands from steering wheel
Clutch solenoid valve (proportional) On Clutch control lock, automatic shift to idle (N) (vehicle stationary)
Clutch position sensor On Clutch control lock, automatic shift to idle (N) (vehicle stationary)
Pump relay control On Vehicle stationary
Buzzer control On Continual functioning
Start enable relay control On Gear shift acceptance limitation for 1, 2, R, N
Brake status switch On With engine off does not accept gear change, engine only starts with gear in idle (N)
Message transmission CAN line On C.C.M. does not check torque with city disabled
Message receiving CAN line On Gear shift acceptance limitation for 1, 2, R, N C.C.M. does not check torque
CFC 208F microprocessor On Gear shift acceptance limitation for 1, 2, R, N
Control unit CFC 208F earth On Total system lock
CFC 208F memory On Gear shift acceptance limitation for 1, 2, R, N
Display serial line control On Gear engaged not displayed
Accumulator discharged On No recovery
Pump relay glued On No recovery
Accelerator pedal On 1, 2, R, N engagement indication not valid and limitation of engine revs.
 Posted by at 8:57 pm
Feb 102015
 

The diagnostics implemented in the control unit CFC 208F allow the testing of the inputs:

  • rev sensor from rev counter module
  • clutch disk speed sensor (gearbox primary)
  • car speed from CAN line (through A.B.S.)

This consists in checking whether or not there is the signal.
The diagnostics on the analog input signals is made checking these type of failures:

  • signal out of electrical range
  • signal out of dynamic range

The diagnostics implemented on the output controls of the control unit CFC 208F concern:

  • the three proportional solenoid valves
  • the two on-off solenoid valves
  • the two relays (hydraulic pump and engine start enable)

The types of failures checked are:

For proportional solenoid valves:

  • short circuit to earth
  • short circuit to +Vbatt
  • circuit open

For ON/OFF solenoid valves:

  • short circuit to earth

Electric pump relay:

  • circuit open
  • short circuit to +Vbatt
  • Start-up enable relay
  • short circuit to earth
  • circuit open

These input signals and output commands are excluded from the diagnosis:

  • brake pedal (except permanent closed circuit for a certain time with car moving)
  • automatic mode (CITY) and door open switches
  • the signals supplied by C.C.M. on CAN network
  • diagnostics serial line (K)
  • signals :key (+15/54) power supply (+30) direct from battery.
 Posted by at 8:45 pm