SPN 0119 Retarder oil pressure
Monitoring strategy
Retarder oil pressure monitoring with T80 oil pressure sensor
Client perception/symptom description
• The central warning light illuminates continuously yellow when driving and when the vehicle is stationary
• Retarder braking mode is not possible
Failure Mode Identification (FMI)
FMI 1 Value too high
Indication on the display
Priority 5 Text
indications
---
Control device conditions
Setting conditions
Retarder oil pressure greater than 1350 mbar even though no braking torque has been requested
Reset conditions
---
Symptoms
Systemic reaction/possible effects
Retarder braking mode is not possible
Substitute reaction
---
Reasons
Possible causes
► T80 oil pressure sensor faulty
► Damaged or disconnected electrical cables and plug connections from the control device
gearbox to the T80 oil pressure sensor or the V97 valve block
► The solenoid/proportional valves in the V97 valve block are faulty
SPN_0119_Retarderöldruck_GTR-SGC-Scania : 2021-09-29 : 2/11
Inspections
Possible control steps
Visual inspections
► Carry out a visual inspection of the T80 oil pressure sensor
► Carry out a visual inspection of the V97 valve block
► Check the lines and plug connections from the transmission control unit to the oil pressure sensor
T80 for damage, abrasion, interruption, short circuit, transition resistance, change in cross-section,
corrosion, correct connection and loose contacts
T80 oil pressure sensor
► Pin assignment:
Contact Action Connection
1 Supply voltage 5 V Gearbox control device
gears, contact B33
2 Sensor ground Gearbox control device
gears, contact B35
3
Sensor output signal
oil pressure (0.6–4.5V / 1–
30 bar)
Gearbox control device
gears, contact B36
► Measured values:
Pressure
oil in
mbar
1000 2000 3000 4000 5000 6000 7000 ...
Tension
In
volts
0.6 0.8 0.9 1.1 1.2 1.3 1.5 …
► Check the supply voltage of the T80 oil pressure sensor in the oil pressure sensor between pin 1 and
pin 2. Set value: 5 V
► Check the signal voltage of the oil pressure sensor T80 in the gearbox control unit
pin B35 (-) and pin B36 (+). Setpoints: see measurement value table
Solenoid/proportional valves in the V97 valve block
► Check the correct operation of the solenoid/proportional valves in the valve block
V97 with MAN-cats and actuator test (retarder xxxx): Acoustic feedback
(ticking test)
SPN_0119_Retarderöldruck_GTR-SGC-Scania : 2021-09-29 : 3/11
Inspections
Possible control steps
Solenoid/proportional valves in the V97 valve block
► Pin assignment:
Contact Action Connection
1 Unused ---
2 Valve control
proportional
Gearbox control device
gears, contact B37
3 Proportional valve mass Gearbox control device
gears, contact B39
4
Valve control
electromagnetic power supply
compressed air
Gearbox control device
gears, contact B34
5 Valve weight
electromagnetic
Gearbox control device
gears, contact B38
6
Valve control
solenoid valve
power supply security
compressed air
Gearbox control device
gears, contact B4
7 Unused ---
► Proportional valve measurement values:
Temperature in °C -40 +20 +125
Resistance in ohms 22.5 29.4 41.5
► Measurement values of solenoid valves:
Temperature in °C -40 +20 +125
Resistance in ohms 98 128 (+10%/-5%) 180
Remedy
Possible remedy
► If necessary, replace the T80 oil pressure sensor
► Repair cables and plug connections if necessary
► Replace the V97 valve block if necessary
SPN_0119_Retarderöldruck_GTR-SGC-Scania : 2021-09-29 : 4/11
Attention
Additional information/tips
► The T80 oil pressure sensor measures the oil pressure in the retarder, which is proportional to the torque
braking
► To check the T80 oil pressure sensor, pressure must be applied to it. Sensor
The oil pressure switch must output a signal of 0.6V ±2% at atmospheric pressure when energized
voltage of 5 V
FMI 2 Value too low
Indication on the display
Priority 5 Text
indications
---
Control device conditions
Setting conditions
Oil pressure in the retarder less than 1000 mbar, although torque above 2000 Nm was requested for longer than
for 7 s
Reset conditions
---
Symptoms
Systemic reaction/possible effects
Retarder braking mode is not possible
Substitute reaction
---
Reasons
Possible causes
► Too little retarder oil
► Low quality of oil in the retarder
► Oil temperature in the retarder too low
► T80 oil pressure sensor faulty
► Damaged or disconnected electrical cables and plug connections from the control device
gear to the T80 oil pressure sensor
► The solenoid valve in the V97 block is faulty
SPN_0119_Retarderöldruck_GTR-SGC-Scania : 2021-09-29 : 5/11
Inspections
Possible control steps
► Check whether the retarder oil quantity is between the minimum and maximum values:
set value approximately 7.9 l
► Check the quality of the oil in the retarder
► Check the oil temperature in the retarder: Setpoint: greater than 0°C
Visual inspections
► Carry out a visual inspection of the T80 oil pressure sensor
► Check the lines and plug connections from the transmission control unit to the oil pressure sensor
T80 for damage, abrasion, interruption, short circuit, transition resistance, change in cross-section,
corrosion, correct connection and loose contacts
T80 oil pressure sensor
►Pin assignment:
Contact Action Connection
1 Supply voltage 5 V Gearbox control device
gears, contact B33
2 Sensor ground Gearbox control device
gears, contact B35
3
Sensor output signal
oil pressure (0.6–4.5V / 1–
30 bar)
Gearbox control device
gears, contact B36
► Measured values:
Pressure
oil in
mbar
1000 2000 3000 4000 5000 6000 7000 ...
Tension
In
volts
0.6 0.8 0.9 1.1 1.2 1.3 1.5 …
► Check the supply voltage of the T80 oil pressure sensor in the oil pressure sensor between pin 1 and
pin 2. Set value: 5 V
► Check the signal voltage of the oil pressure sensor T80 in the gearbox control unit
pin B35 (-) and pin B36 (+). Setpoints: see measurement value table
Solenoid/proportional valves in the V97 valve block
► Check the correct operation of the solenoid/proportional valves in the valve block
V97 with MAN-cats and actuator test (retarder xxxx): Acoustic feedback
(ticking test)
SPN_0119_Retarderöldruck_GTR-SGC-Scania : 2021-09-29 : 6/11
Inspections
Possible control steps
Solenoid/proportional valves in the V97 valve block
► Pin assignment:
Contact Action Connection
1 Unused ---
2 Valve control
proportional
Gearbox control device
gears, contact B37
3 Proportional valve mass Gearbox control device
gears, contact B39
4
Valve control
electromagnetic power supply
compressed air
Gearbox control device
gears, contact B34
5 Valve weight
electromagnetic
Gearbox control device
gears, contact B38
6
Valve control
solenoid valve
power supply security
compressed air
Gearbox control device
gears, contact B4
7 Unused ---
► Proportional valve measurement values:
Temperature in °C -40 +20 +125
Resistance in ohms 22.5 29.4 41.5
► Measurement values of solenoid valves:
Temperature in °C -40 +20 +125
Resistance in ohms 98 128 (+10%/-5%) 180
SPN_0119_Retarderöldruck_GTR-SGC-Scania : 2021-09-29 : 7/11
Remedy
Possible remedy
► Correct the retarder oil quantity so that it is between the minimum value and
maximum: set value approximately 7.9 l
► Change the retarder oil if necessary
► Replace the retarder oil filter if necessary
► If necessary, replace the T80 oil pressure sensor
► Repair cables and plug connections if necessary
► Replace the V97 valve block if necessary
Attention
Additional information/tips
► The T80 oil pressure sensor measures the oil pressure in the retarder, which is proportional to the torque
braking
► To check the T80 oil pressure sensor, pressure must be applied to it. Sensor
The oil pressure switch must output a signal of 0.6V ±2% at atmospheric pressure when energized
voltage of 5 V
FMI 5 Short circuit to ground
Indication on the display
Priority 5 Text
indications
---
Control device conditions
Setting conditions
The voltage of the T80 oil pressure sensor is below 0.175 V for longer than 500 ms
The T80 oil pressure sensor has a short circuit to a low voltage source
Reset conditions
---
Symptoms
Systemic reaction/possible effects
Retarder braking mode is not possible
Substitute reaction
---
SPN_0119_Retarderöldruck_GTR-SGC-Scania : 2021-09-29 : 8/11
Reasons
Possible causes
► T80 oil pressure sensor faulty
► Damaged or disconnected electrical cables and plug connections from the control device
gearbox to the T80 oil pressure sensor or the V97 valve block
Inspections
Possible control steps
Visual inspections
► Carry out a visual inspection of the T80 oil pressure sensor
► Check the lines and plug connections from the transmission control unit to the oil pressure sensor
T80 for damage, abrasion, interruption, short circuit, transition resistance, change in cross-section,
corrosion, correct connection and loose contacts
T80 oil pressure sensor
►Pin assignment:
Contact Action Connection
1 Supply voltage 5 V Gearbox control device
gears, contact B33
2 Sensor ground Gearbox control device
gears, contact B35
3
Sensor output signal
oil pressure (0.6–4.5V / 1–
30 bar)
Gearbox control device
gears, contact B36
► Measured values:
Pressure
oil in
mbar
1000 2000 3000 4000 5000 6000 7000 ...
Tension
In
volts
0.6 0.8 0.9 1.1 1.2 1.3 1.5 …
► Check the supply voltage of the T80 oil pressure sensor in the oil pressure sensor between pin 1 and
pin 2. Set value: 5 V
► Check the signal voltage of the oil pressure sensor T80 in the gearbox control unit
pin B35 (-) and pin B36 (+). Setpoints: see measurement value table
SPN_0119_Retarderöldruck_GTR-SGC-Scania : 2021-09-29 : 9/11
Remedy
Possible remedy
► If necessary, replace the T80 oil pressure sensor
► Repair cables and plug connections if necessary
Attention
Additional information/tips
► The T80 oil pressure sensor measures the oil pressure in the retarder, which is proportional to the torque
braking
► To check the T80 oil pressure sensor, pressure must be applied to it. Sensor
The oil pressure switch must output a signal of 0.6V ±2% at atmospheric pressure when energized
voltage of 5 V
FMI 12 Interrupt or short to UBatt+
Indication on the display
Priority 5 Text
indications
---
Control device conditions
Setting conditions
The voltage of the T80 oil pressure sensor is above 4.60 V for a period longer than 500 ms
Reset conditions
---
Symptoms
Systemic reaction/possible effects
Retarder braking mode is not possible
Substitute reaction
---
Reasons
Possible causes
► T80 oil pressure sensor faulty
► Damaged or disconnected electrical cables and plug connections from the control device
gear to the T80 oil pressure sensor
SPN_0119_Retarderöldruck_GTR-SGC-Scania : 2021-09-29 : 10/11
Inspections
Possible control steps
Visual inspections
► Carry out a visual inspection of the T80 oil pressure sensor
► Check the lines and plug connections from the transmission control unit to the oil pressure sensor
T80 for damage, abrasion, interruption, short circuit, transition resistance, change in cross-section,
corrosion, correct connection and loose contacts
T80 oil pressure sensor
►Pin assignment:
Contact Action Connection
1 Supply voltage 5 V Gearbox control device
gears, contact B33
2 Sensor ground Gearbox control device
gears, contact B35
3
Sensor output signal
oil pressure (0.6–4.5V / 1–
30 bar)
Gearbox control device
gears, contact B36
►Measured values:
Pressure
oil in
mbar
1000 2000 3000 4000 5000 6000 7000 ...
Tension
In
volts
0.6 0.8 0.9 1.1 1.2 1.3 1.5 …
► Check the supply voltage of the T80 oil pressure sensor in the oil pressure sensor between pin 1 and
pin 2. Set value: 5 V
► Check the signal voltage of the oil pressure sensor T80 in the gearbox control unit
pin B35 (-) and pin B36 (+). Setpoints: see measurement value table
Remedy
Possible remedy
► If necessary, replace the T80 oil pressure sensor
► Repair cables and plug connections if necessary
SPN_0119_Retarderöldruck_GTR-SGC-Scania : 2021-09-29 : 11/11
Attention
Additional information/tips
► The T80 oil pressure sensor measures the oil pressure in the retarder, which is proportional to the torque
braking
► To check the T80 oil pressure sensor, pressure must be applied to it. Sensor
The oil pressure switch must output a signal of 0.6V ±2% at atmospheric pressure when energized
in the latest TG3 model there is already a full lcd
