300Tdi Discovery
ZF
11
FAULT DIAGNOSIS
SYMPTOM 10 - None or harsh engagement of
direct drive clutch
NOTE: The direct drive clutch will only
engage if 4th gear is engaged at 40 to 45
mph.
Carry out road test pressure check with gauge
connected to torque converter.
œ Normal pressure
FAULT - Failed direct drive clutch
œ Pressures correct but remains high
FAULTS POSSIBLE -
Direct drive clutch and torque converter
control valve stuck
Hysteresis valve stuck
Direct drive clutch control valve stuck
SYMPTOM 11 - Direct drive clutch shift point
incorrect or at low speed
NOTE: Direct drive clutch engagement at
low speed will cause vibration in the
torque converter
Carry out mainline and torque converter pressure
check
œ Normal pressure
FAULT - Governor valve sticking
œ Low or incorrect pressure
FAULTS POSSIBLE -
Direct drive clutch and torque converter
control valve sticking.
Hysteresis valve stuck.
Direct drive clutch control valve stuck.
SYMPTOM 12 - Drives in ’D’ but immediately
upshifts to 3rd
FAULT - 2nd to 3rd shift valve stuck.
SYMPTOM 13 - With ’D’ selected vehicle starts in
2nd
FAULTS POSSIBLE -
1st and 2nd shift valve stuck.
Governor sleeve sticking.
SYMPTOM 14 - With ’D’ selected vehicle starts in
3rd
FAULTS POSSIBLE -
1st to 2nd and 2nd to 3rd shift valves stuck.
Governor sleeve sticking.
SYMPTOM 15 - No kickdown 4th to 3rd
FAULT - 4th to 3rd kickdown valve stuck.
SYMPTOM 16 - Upshifts/downshifts and kickdown
shifts at incorrect road speeds
Check throttle kickdown cable adjustment
Carry out main line pressure check
œ Normal pressure
FAULT - Governor valve sticking
œ Incorrect pressure
FAULTS POSSIBLE -
Incorrect throttle valve adjustment
Primary regulator sticking
SYMPTOM 17 - No upshifts at light throttle
FAULTS POSSIBLE
Governor valve sticking
Shift valves sticking
SYMPTOM 18 - No engine braking ’3’ selected 3rd
gear
FAULT - Clutch ’C’
SYMPTOM 19 - Delayed or no downshift occurs
when making a manual selection from ’3’ to ’2’
FAULTS POSSIBLE -
2nd and 3rd upshift valve sticking.
Governor valve sticking.
’2’ Position interlock valve sticking.
SYMPTOM 20 - At speeds below 28 mph when
making a manual selection from ’2’ to ’1’,
downshift is delayed or does not occur
FAULTS POSSIBLE -
Governor sticking.
1st to 2nd shift valve sticking.
’1’ Position interlock valve sticking.
SYMPTOM 21 - ’1’ Selected 1st gear no engine
braking
FAULT - Clutch brake 3
SYMPTOM 22 - ’2’ Selected 2nd gear no engine
braking
FAULT - Clutch brake 1
SYMPTOM 23 - Vehicle drives forward in ’N’
FAULT - Clutch ’A’ stuck
