P2601-778

P310 HYBRID VEHICLE CONTROL: HYBRID CONTROL SYSTEM: P2601-778: Coolant Pump Control Circuit Range / Performance

DTC P2601-778 - Coolant Pump Control Circuit Range / Performance

DESCRIPTION
HINT: Although the DTC title refers to "coolant pump", this DTC is related to the oil pump control circuit.

The hybrid vehicle control ECU detects the MG1 and MG2 temperature based on signals from the generator and motor temperature sensors and activates the OIL PMP relay and oil pump driver (oil pump with motor assembly).
The hybrid vehicle control ECU monitors OPST signals from the oil pump driver and detects malfunctions.

The oil pump with motor assembly is activated when:
1. MG1 temperature is 248°F (120°C) or more
2. MG2 temperature is 266°F (130°C) or more and the MG1 temperature is 212°F (100°C) or more
HINT:
- If the second condition occurs, and the oil pump with motor assembly does not activate even though the MG1 temperature is 212°F (100°C) or more, the hybrid vehicle control ECU will attempt to activate it when the MG1 temperature changes to 230°F (110°C), 248°F (120°C), 266°F (130°C), 284°F (140°C) and 302°F (150°C) respectively.
- The oil pump cannot be activated only with the OIL PMP relay on. It is activated after receiving the command signals (OPM1) from the hybrid vehicle control ECU.







INSPECTION PROCEDURE
NOTICE:
- When troubleshooting the oil pump with motor assembly, check for the following conditions:

- ATF temperature inside the oil cooler is 41°F (5°C) or more.
- The ambient temperature sensor value is 41°F (5°C) or more.

PROCEDURE

1. CHECK AMBIENT TEMPERATURE SENSOR
HINT: The ambient temperature sensor value is used to detect DTC P2601-778. Check that the ambient temperature sensor operates normally, because P2601-778 may be mistakenly detected due to a malfunction in the ambient temperature sensor.
(a) Following the troubleshooting procedures for the ambient temperature sensor, check that the ambient temperature sensor operates normally.
NG -- GO TO AMBIENT TEMPERATURE SENSOR INSPECTION
OK -- Continue to next step.
2. CHECK FLUID PIPES
(a) Check that there is no clogging in the pipes among the oil pump with motor assembly, oil cooler, and hybrid vehicle transaxle.
NG -- REPAIR OR REPLACE FLUID PIPES
OK -- Continue to next step.
3. CHECK OPERATION OF OIL PUMP WITH MOTOR ASSEMBLY
(a) Connect the Techstream to the DLC3.
(b) Turn the power switch on (IG).
(c) Select the following menu items: Powertrain / Hybrid Control / Active Test / Inspection Mode - 2WD Inspection.
(d) Turn the power switch on (READY) to enter oil pump forced activation mode.
(e) Check if DTCs are output.
Result:





HINT: If the vehicle is driven at high loads when it is cold, the temperature of the motor generator might increase until it reaches the operating temperature of the oil pump with motor assembly. This temperature increase of the motor generator could happen before the temperature of the ATF goes up. When this DTC is stored as a result of the above conditions, it is not necessary to replace the oil pump with motor assembly as it is not malfunctioning. However, the DTC is stored because the detection conditions of the DTC have been met.
When ATF whose low temperature viscosity is higher than ATF-WS is used, DTC P2601-778 might be output.

B -- REPLACE OIL PUMP WITH MOTOR ASSEMBLY
A -- COMPLETED