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DTC P1059: Generator control unit oil temperature sensor fails (short to power supply, short circuit)
DTC P105A: Generator control unit oil temperature sensor fails (short to ground, open circuit)
 
 
 
 
MONITOR EXECUTION
  • Continuous
 
 
MONITOR EXECUTION CONDITIONS (Other monitor and Sensor)
Other Monitor (There is no temporary DTC stored in memory for the item monitored below)
  • Not applicable
Sensor (The sensor below is determined to be normal)
  • Not applicable
 
 
DTC SET CONDITIONS
Logic Flow Chart
Check Conditions
  • Power drive unit (GCU) power supply voltage is 8 volts to 16 volts.
Judgment Criterion <DTC P1059>
  • Change of the power drive unit (GCU) IGBT temperature sensor voltage is more than 4.884 volts [201°C (394°F)] for 0.5 second.
Judgment Criterion <DTC P105A>
  • Change of the power drive unit (GCU) voltage is less than 0.031 volt [-51°C (-60°F)] for 0.5 second.
 
 
OBD-II DRIVE CYCLE PATTERN
  • Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 1 .
 
 
PROBABLE CAUSES
  • The thermistor oil temperature circuit fails
  • Malfunction of the generator
  • Malfunction of the power drive unit [generator control unit (GCU)]
  • Damaged wiring harness

 
 
DIAGNOSIS
Required Special Tools
  • MB991223: Wiring harness set
  • MB992006: Extra fine probe
STEP 1. Using scan tool (M.U.T.-IIISE), check whether the DTC is set.
Check if the DTC P104C is set in the power drive unit [generator control unit (GCU)].
Is the DTC set?
Carry out troubleshooting for the DTC P104C (Refer to ). Then go to Step 3.
Go to Step 2.
 
STEP 2. Check the resistance in the oil temperature sensor.
(1) Disconnect the power drive unit connector.
(2) Check the conduction of the harness between the power drive unit and the generator and measure the resistance value of the oil temperature sensor in the power drive unit connector terminals.
 
Terminal symbolNormal value
TH0 to TG0
  • Approx. 400kΩ to 600kΩ at -20°C (-4°F)
  • Approx. 140kΩ to 200kΩ at 0°C (32°F)
  • Approx. 55kΩ to 70kΩ at 20°C (68°F)
  • Approx. 23kΩ to 30kΩ at 40°C (104°F)
Is the check result normal?
Replace the power drive unit (Refer to ). Then go to Step 3.
Replace the wiring harness (TH0 line, TG0 line) and the generator (Refer to ). Then go to Step 3.
 
STEP 3. Test the OBD-II drive cycle.
(1) Carry out a test drive with the drive cycle pattern. Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 1 .
(2) Check the DTC.
Is the DTC set?
Retry the troubleshooting.
The inspection is complete.