DTC P0C4A (1074)
DTC P0C4A (1074): ES Coolant Pump Control Performance
General Description
The electric powertrain system has a liquid cooling system, which uses an electric water pump to circulate the coolant. The electric water pump speed is controlled according to the drive command from the battery condition monitor module A and the speed is returned to the battery condition monitor module A. The battery condition monitor module A monitors the electric water pump speed and when the actual speed is higher or lower than normal speed for a set time, the battery condition monitor module A detects a malfunction and stores a DTC.
Monitor Execution, Sequence, Duration, DTC Type
| Execution | Continuous |
| Sequence | None |
| Duration | 3 seconds or more |
| DTC Type | Two drive cycles, MIL on, POWER SYSTEM indicator on, 12 volt battery charging system indicator off |
Enable Conditions
| Condition | Minimum | Maximum |
|---|---|---|
| Battery condition monitor module A power-supply voltage | 10.7 V | - |
| ES electric water pump duty command | 40 % | - |
| Vehicle condition | Vehicle ON mode, or Plug-in charge on, or Plug-in quick charge on | |
Malfunction Threshold
One of these symptoms occurs:
- Symptom 1
The ES electric water pump is 530 RPM or less for at least 10 seconds.
- Symptom 2
The ES electric water pump is 2, 853 RPM or more for at least 1.5 seconds.
Possible Cause
- ES electric water pump NESEWP line open
- ES electric water pump relay ESEWPRLY line open
- ES electric water pump power supply line open (includes fuse blown)
- ES electric water pump ESEWPCTL line short to ground
- ES electric water pump NESEWP line short to ground
- ES electric water pump power supply line short to ground
- Coolant leak
- Coolant air inclusion
- ES electric water pump relay stuck off
- ES electric water pump internal failure
Confirmation Procedure
Operating Condition
Turn the vehicle to the ON mode.
With the HDS
Select the ES Electric Water Pump Test in the Function Test with the HDS.
Diagnosis Details
Conditions for setting the DTC
When a malfunction is detected during the first drive cycle, a Pending DTC is stored in the battery condition monitor module A memory. If the malfunction returns in the next (second) drive cycle, the MIL and the POWER SYSTEM indicator comes on and a Confirmed DTC and the freeze data are stored.
Conditions for clearing the DTC
The MIL and the POWER SYSTEM indicator is cleared if the malfunction does not return in the next trip in which the diagnostic runs. The MIL and the POWER SYSTEM indicator, the Pending DTC, the Confirmed DTC, and the freeze data can be cleared with the scan tool Clear command.