DTC P2602
DTC P2602: Electric Engine Coolant Pump Circuit Low 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 (EWPC) to the electric engine coolant pump and feeds back the revolution speed (EWP REV) 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 low continuously for the prescribed time when the PCM outputs 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 | 5 seconds or more |
| DTC Type | One drive cycle, MIL on |
Enable Conditions
| Condition | Minimum | Maximum |
|---|---|---|
| Engine coolant temperature [ECT Sensor 1] | -13 deg.F (-25 deg.C) | - |
| 12 volt battery voltage [Battery] | 10.5 V | 16.0 V |
| Electric engine coolant pump drive duty | 40 % | - |
| Vehicle | ON mode | |
[ ]: HDS Parameter
Malfunction Threshold
The electric engine coolant pump is 600 RPM or less for at least 5 seconds.
Possible Cause
- Electric engine coolant pump power supply line open
- Electric engine coolant pump EWPREV line short to ground
- Electric engine coolant pump ground line open
- Electric engine coolant pump EWPC line short to ground
- Electric engine coolant pump EWPREV line open
- Electric engine coolant pump power supply line short to ground
- Electric engine coolant pump failure
- PCM failure
Confirmation Procedure
Operating Condition
Enter the maintenance mode, then start the engine.
With the HDS
Do the ELECTRIC WATER PUMP TEST in the INSPECTION MENU with the HDS.
Diagnosis Details
Conditions for setting the DTC
When a malfunction is detected, the MIL comes on and a Pending DTC, a Confirmed DTC, and the freeze data are stored in the PCM memory.
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.