Operation and maintenance manual

Section 120-0010
Transmission - Transmission and Mounting
SM 2124 Rev 3 8-03
20
Fault MEANING OF CODE TCU reaction Checks Remarks
Code possible reason for fault detection
(hex)
B5
SLIPPAGE AT CLUTCH KV TCU shifts to neutral •check pressure at clutch KV
TCU calculates a differential speed at closed clutch KV. OP-Mode: limp home •check main press. in system
If this calculated value is out of range, TCU interprets if failure at another •check sensor gap at internal
this as slipping clutch. clutch is pending speed sensor
• low pressure at clutch KV TCU shifts to neutral •check sensor gap at turbine
• low main pressure OP-Mode: TCU shutdown speed sensor
• wrong signal at internal speed sensor •check signal at internal
• wrong signal at turbine speed sensor speed sensor
• wrong size of the sensor gap •check signal at turbine
• clutch is defective speed sensor
•replace clutch
B6
SLIPPAGE AT CLUTCH KR TCU shifts to neutral •check pressure at clutch KR
TCU calculates a differential speed at closed clutch KR. OP-Mode: limp home •check main press. in system
If this calculated value is out of range, TCU interprets if failure at another •check sensor gap at internal
this as slipping clutch. clutch is pending speed sensor
• low pressure at clutch KR TCU shifts to neutral •check sensor gap at turbine
• low main pressure OP-Mode: TCU shutdown speed sensor
• wrong signal at internal speed sensor •check signal at internal
• wrong signal at turbine speed sensor speed sensor
• wrong size of the sensor gap •check signal at turbine
• clutch is defective speed sensor
•replace clutch
B7
OVERTEMP SUMP no reaction •cool down machine
TCU measured a temperature in the oil sump that is OP-Mode: normal •check oil level
over the allowed threshold. •check temperature sensor
B8
OVERTEMP RETARDER TCU disables retarder •cool down machine
TCU measured a temperature in the retarder oil that is OP-Mode: normal •check oil level
over the allowed threshold. •check temperature sensor
B9
OVERSPEED ENGINE retarder applies - not used
OP-Mode: normal
BA
DIFFERENTIAL PRESSURE OIL FILTER no reaction • check oil filter
TCU measured a voltage at differential pressure switch OP-Mode: normal •check wiring from TCU to
out of the allowed range. differential pressure switch
• oil filter is polluted •check differential pressure
• cable/connector is broken or cable/connector is switch (measure resistance)
contacted to battery voltage or vehicle ground
• differential pressure switch is defective
BB
SLIPPAGE AT CONVERTER LOCKUP CLUTCH •check pressure at
TCU calculates a differential speed at closed converter converter lockup clutch
lockup clutch. If this calculated value is out of range, •check main pressure in the
TCU interprets this as slipping clutch. system
• low pressure at converter lockup clutch •check sensor gap at engine
• low main pressure speed sensor
• wrong signal at engine speed sensor •check sensor gap at turbine
• wrong signal at turbine speed sensor speed sensor
• wrong size of the sensor gap •check signal at engine
• clutch is defective speed sensor
•check signal at turbine
speed sensor
•replace clutch
BD
S.C. TO GROUND AT ENGINE BRAKE SOLENOID no reaction •check cable from TCU to
1)
see figure 8
TCU detected a wrong voltage at the output pin, that OP-mode: normal engine brake solenoid
looks like a s.c. to vehicle ground •check connectors from
• cable is defective and is contacted to vehicle ground engine brake solenoid
• engine brake solenoid has an internal defect to TCU
• connector pin is contacted to vehicle ground • check the resistance
1)
of
engine brake solenoid