DTC P2603
DTC P2603: Electric Engine Coolant Pump Circuit High Voltage
General Description
The electric engine coolant pump varies the pump revolution speed according to the powertrain control module (PCM) outputs signal. The PCM outputs signal (EWP_C(SWP)) to the electric engine coolant pump and feeds back the revolution speed (EWP_REV(NWP)) from the electric engine coolant pump to control the revolution speed. Since the flow rate of the pump is in proportion to the revolution speed, the flow rate increases as the revolution speed is raised. If the electric engine coolant pump revolution speed is more than a specified value continuously for the prescribed time when the PCM outputs stop signal to the electric engine coolant pump, the PCM detects a malfunction and stores a DTC.
Monitor Execution, Sequence, Duration, DTC Type
| Execution | Continuous |
| Sequence | None |
| Duration | 6.0 seconds or more |
| DTC Type | Two drive cycles, MIL on |
Enable Conditions
| Condition | Minimum | Maximum |
|---|---|---|
| Electric engine coolant pump drive duty | - | 8 % |
| Vehicle | ON mode | |
Malfunction Threshold
The electric engine coolant pump is at 600 rpm or more for at least 6.0 seconds
Possible Cause
NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
- Electric engine coolant pump EWP_C(SWP) line open
- Electric engine coolant pump EWP_C(SWP) line short to power
- Electric engine coolant pump failure
- PCM failure
Confirmation Procedure
Operating Condition
None.
With the HDS
Select the Electric Water Pump TEST in the Function Test Menu 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 PCM memory. If the malfunction returns in the next (second) drive cycle, the MIL comes on and a Confirmed DTC and the freeze data are stored.
Conditions for clearing the DTC
The MIL is cleared if the malfunction does not return in three consecutive trips in which the diagnostic runs. The MIL, the Pending DTC, the Confirmed DTC, and the freeze data can be cleared with the scan tool Clear command or by disconnecting the 12 volt battery.