Toyota Corolla Cross: Auxiliary Transmission Fluid Pump Control Module Feedback Signal Circuit Short to Ground (P0C2B11)

Toyota Corolla Cross (2022-2024) Service Manual / Engine & Hybrid System / Stop And Start / Stop And Start System / Auxiliary Transmission Fluid Pump Control Module Feedback Signal Circuit Short to Ground (P0C2B11)

DESCRIPTION

The oil pump of the continuously variable transaxle assembly stops operating when the engine is stopped by stop and start control. While the engine is stopped by stop and start control, the oil pump with motor assembly is operated continuously ensuring optimal continuously variable transaxle oil pressure and smooth start-off when the engine is restarted.

The engine stop and start ECU supplies power to the oil pump with motor assembly via terminal OP21 and operates the oil pump with motor assembly in accordance with signals sent from terminal OPM1. The oil pump with motor assembly sends operating speed signals to the engine stop and start ECU via the NOPM signal line.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	MIL	Warning Indicate	Note
P0C2B11	Auxiliary Transmission Fluid Pump Control Module Feedback Signal Circuit Short to Ground	Both of the following conditions are met for 2 seconds or more (1 trip detection logic): Oil pump motor relay circuit in the engine stop and start ECU is off Oil pump with motor assembly power supply malfunction (Oil pump motor relay circuit in the engine stop and start ECU stuck on or shorted) or a short to ground in the NOPM circuit	Wire harness or connector Oil pump with motor assembly Engine stop and start ECU	Comes on (For Mexico Models: Does not come on)	Does not come on (For Mexico Models: Blinks)	SAE Code: P0C2D

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Warning Indicate

Note

P0C2B11

Auxiliary Transmission Fluid Pump Control Module Feedback Signal Circuit Short to Ground

Both of the following conditions are met for 2 seconds or more (1 trip detection logic):

Oil pump motor relay circuit in the engine stop and start ECU is off
Oil pump with motor assembly power supply malfunction (Oil pump motor relay circuit in the engine stop and start ECU stuck on or shorted) or a short to ground in the NOPM circuit

Wire harness or connector
Oil pump with motor assembly
Engine stop and start ECU

Comes on (For Mexico Models: Does not come on)

Does not come on (For Mexico Models: Blinks)

SAE Code: P0C2D

MONITOR STRATEGY

Related DTCs	P0C2D: Electric transmission fluid pump (starter / generator control module) range check (low voltage)
Required Sensors/Components (Main)	Engine stop and start ECU
Required Sensors/Components (Related)	-
Frequency of Operation	Continuous
Duration	2 seconds
MIL Operation	2 driving cycles
Sequence of Operation	None

TYPICAL ENABLING CONDITIONS

All of the following conditions are met	-
Battery voltage	10.5 V or higher
Time after battery voltage 8 V or higher	0.5 seconds or more
Write inhibit	permit
Time after write status forbiddance to permit	0.5 seconds or more
Ignition switch	ON
Time after ignition switch is off to ON	0.5 seconds or more
Starter	Off
Time after starter on to off	0.5 seconds or more
A/D converter fail (P060B)	Not detected
Time after command to electric transmission fluid pump power supply relay off	2 seconds or more

TYPICAL MALFUNCTION THRESHOLDS

Electric transmission fluid pump feedback signal terminal voltage level

Low

CONFIRMATION DRIVING PATTERN

HINT:

If the cable is disconnected from the auxiliary battery terminal, stop and start control is prohibited until refresh charge is completed.
In this case, let the vehicle idle to complete the refresh charge. The refresh charge is complete when the Data List item Status of Battery Charge Control changes from "Refresh Charge Mode". (Usually, by idling the engine for 5 to 60 minutes with the auxiliary battery fluid temperature at 11°C (52°F) or higher, the refresh charge will be completed.)
If the GTS is not available and the Data List item Status of Battery Charge Control cannot be checked, charge the auxiliary battery by idling the engine for approximately 5 to 60 minutes or driving the vehicle, and then drive the vehicle and check that stop and start control operates.
If the engine is started with the hood open, the system determines that a jump start has occurred. Therefore, make sure that the hood is closed before starting the engine and driving the vehicle.
After the refresh charge completes, turn the ignition switch off, wait for at least 30 seconds, and then start the engine again. If the vehicle enters refresh charge mode again while the engine is idling, the initial refresh charge did not properly complete, so wait for the refresh charge to complete.
Allow the engine to idle for 3 minutes after it is warmed up and check that the engine idle speed is within 50 rpm of the target idle speed.

CONFIRMATION AFTER TROUBLESHOOTING

(a) Clear the DTCs.

Powertrain > Stop and Start > Clear DTCs

(b) Start the engine and warm it up.

CAUTION:

When performing Confirmation Driving Pattern, obey all speed limits and traffic laws.

(d) Depress the brake pedal and stop the vehicle.

(e) Keep the engine stopped by stop and start control. (Keep the shift lever in D.)

(f) Release the brake pedal with the shift lever in D to start the engine.

(g) Check that no DTCs are output.

Powertrain > Stop and Start > Trouble Codes

STOP AND START SYSTEM OPERATION CHECK

Click here

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

Before replacing the engine stop and start ECU, read the number of starter operations and write it into a new engine stop and start ECU.
Click here
After replacing the engine stop and start ECU, perform learning of the external backup boost converter (eco run vehicle converter assembly).
Click here
After replacing the engine stop and start ECU or air conditioning amplifier assembly, reset and perform learning of the air conditioning information in the engine stop and start ECU.
Click here
When the engine stop and start ECU or oil pump with motor assembly is replaced, check the oil pump with motor assembly.
Click here

HINT:

Using the GTS, read the freeze frame data before troubleshooting. System condition information is recorded as freeze frame data the moment a DTC is stored. This information can be useful when troubleshooting.
Click here
DTCs for the stop and start system are not cleared even if the malfunction has been repaired. After repairing the malfunction, be sure to clear the DTCs.

PROCEDURE

1.	CHECK HARNESS AND CONNECTOR (ENGINE STOP AND START ECU - OIL PUMP WITH MOTOR ASSEMBLY)

(a) Disconnect the A168 and A169 engine stop and start ECU connectors.

(b) Disconnect the C134 oil pump with motor assembly connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
A169-27 (NOPM) - C134-2 (OPST)	Always	Below 1 Ω
A168-6 (OP21) - C134-4 (+B)	Always	Below 1 Ω
A169-27 (NOPM) - Body ground and other terminals	Always	10 kΩ or higher
C134-2 (OPST) - Body ground and other terminals	Always	10 kΩ or higher
A168-6 (OP21) - Body ground and other terminals	Always	10 kΩ or higher
C134-4 (+B) - Body ground and other terminals	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

2.	CHECK ENGINE STOP AND START ECU (NOPM TERMINAL VOLTAGE)

Component with harness connected

(Engine Stop and Start ECU)

(a) Disconnect the oil pump with motor assembly connector.

(b) Turn the ignition switch to ON.

Standard Voltage:

Tester Connection	Condition	Specified Condition
A169-27 (NOPM) - A169-6 (DGND)	Ignition switch ON	10 to 14 V

REPLACE OIL PUMP (CONTINUOUSLY VARIABLE TRANSAXLE ASSEMBLY)

for 2WD: Click here
for AWD: Click here

REPLACE ENGINE STOP AND START ECU

SEE MORE:

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Installation

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Toyota Corolla Cross: Auxiliary Transmission Fluid Pump Control Module Feedback Signal Circuit Short to Ground (P0C2B11)

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