DTC P2601

DTC P2601: Electric Engine Coolant Pump Range/Performance Problem

General Description

Courtesy of HONDA, U.S.A., INC.

Courtesy of HONDA, U.S.A., INC.

Courtesy of HONDA, U.S.A., INC.

The electric engine coolant pump cools the engine. The pump motor speed is varied by a drive duty command and outputs pump speed to the powertrain control module (PCM). Malfunction detection is performed by comparing the drive duty command to the electric engine coolant pump and pump speed. If the pump speed is higher or lower than the drive duty command by the prescribed value, the PCM detects a malfunction and stores a DTC.

Monitor Execution, Sequence, Duration, DTC Type

Execution	Once per driving cycle
Sequence	None
Duration	10 seconds or more
DTC Type	Two drive cycles, 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

[ ]: HDS Parameter

Malfunction Threshold

Either one of the conditions is met for at least 10 seconds:

When the pump speed is lower than the drive duty command.

Drive duty command	Pump speed
45 %	0 RPM
90 %	2, 000 RPM

When the pump speed is higher than the drive duty command while the 12 volt battery voltage is 14 V.

Drive duty command	Pump speed
0 %	3, 000 RPM
45 %	5, 500 RPM

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 lock
Electric engine coolant pump impeller damage

Confirmation Procedure

Operating Condition

Enter the maintenance mode, then start the engine.
Hold the engine speed [Engine Speed] at 1, 000 RPM, and wait for at least 10 seconds.
Hold the engine speed [Engine Speed] at 2, 000 RPM, and wait for at least 10 seconds.
Hold the engine speed [Engine Speed] at 3, 000 RPM, and wait for at least 10 seconds.

With the HDS

Select the ELECTRIC WATER PUMP TEST in the INSPECTION MENU with the HDS.

Diagnosis Details

Conditions for setting the DTC

When a malfunction is detected during the first drive cycle with the engine coolant temperature and intake air temperature at engine start-up within the specified temperature range, a Pending DTC is stored in the PCM memory. If the malfunction returns in the next (second) drive cycle with the engine coolant temperature and intake air temperature at engine start-up within the specified temperature range, the MIL comes on and a Confirmed DTC, the freeze data, and the on-board snapshot 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, the freeze data, and the on-board snapshot can be cleared with the scan tool Clear command or by disconnecting the 12 volt battery.