STOP AND START: STOP AND START SYSTEM: P164400; ECU Malfunction (Starter Circuit); 2019 - 2021 MY RAV4 [11/2018

Last Modified: 01-30-2024	6.11:8.1.0	Doc ID: RM100000001EEKF
Model Year Start: 2019	Model: RAV4	Prod Date Range: [11/2018 - 12/2021]
Title: STOP AND START: STOP AND START SYSTEM: P164400; ECU Malfunction (Starter Circuit); 2019 - 2021 MY RAV4 [11/2018 - 12/2021]

DTC

P164400

ECU Malfunction (Starter Circuit)

DESCRIPTION

If a malfunction is detected in the starter circuit, the engine stop and start ECU stores DTC P164400 and blinks the stop and start cancel indicator.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	Warning Indicate	Memory	Note
P164400	ECU Malfunction (Starter Circuit)	Both of the following conditions are met for 0.2 seconds or more (1 trip detection logic): Ignition switch ON. Malfunction in starter circuit (STA or STA2).	Wire harness or connector ST NO. 1 relay ST NO. 2 relay Engine stop and start ECU	Blinks	DTC stored	SAE Code: P1644

CONFIRMATION DRIVING PATTERN

HINT:

If the cable is disconnected from the 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, idling the engine for 5 to 60 minutes with the battery fluid temperature at 11°C (51°F) or higher, the refresh charge will be completed.)
If the Techstream is not available and the Data List item "Status of Battery Charge Control" cannot be checked, charge the 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) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(d) Clear the DTCs.

Powertrain > Stop and Start > Clear DTCs

(e) Start the engine and warm it up.

(f) Drive the vehicle at 7 km/h (4 mph) or more.

CAUTION:

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

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

(h) Allow the engine to stop by stop and start control. (Keep the shift lever in D.)

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

(j) Check that DTCs are not output.

Powertrain > Stop and Start > Trouble Codes

STOP AND START SYSTEM OPERATION CHECK

HINT:

If the cable is disconnected from the 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, idling the engine for 5 to 60 minutes with the battery fluid temperature at 11°C (51°F) or higher, the refresh charge will be completed.)
If the Techstream is not available and the Data List item "Status of Battery Charge Control" cannot be checked, charge the 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.

(a) Start the engine and warm it up.

(b) Turn the air conditioning system off.

CAUTION:

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

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

(e) Allow the engine to stop 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.

WIRING DIAGRAM

Refer to DTC P061519.

Click here

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 or air conditioning amplifier assembly, reset and perform learning of the air conditioning information in the engine stop and start ECU.
Click here
After replacing the engine stop and start ECU or airbag ECU assembly, clear and calibrate the deceleration sensor zero point in the engine stop and start ECU.
Click here
When the engine stop and start ECU or oil pump with solenoid assembly is replaced, check the oil pump with solenoid assembly.
Click here
Inspect the fuses for circuits related to this system before performing the following procedure.

HINT:

If DTCs P060B1C (Analog to Digital Converter Circuit Voltage Out of Range), P060B49 (Analog to Digital Converter Internal Electronic Failure) or P060B71 (Analog to Digital Converter Actuator Stuck) and P164400 (ECU Malfunction (Starter Circuit)) are output simultaneously, perform troubleshooting for DTC P060B1C, P060B49 or P060B71 first as it may have caused DTC P164400 to be stored.
Click here
If DTCs P061519 (Starter Relay Circuit Current Above Threshold) and P164400 (ECU Malfunction (Starter Circuit)) are output simultaneously, perform troubleshooting for DTC P061519 first as it may have caused DTC P164400 to be stored.
Click here
Using the Techstream, 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.
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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.
Click here

PROCEDURE

1.	CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P164400)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(d) Enter the following menus: Powertrain / Stop and Start / Trouble Codes.

(e) Read the DTCs.

Powertrain > Stop and Start > Trouble Codes

Result	Proceed to
DTC P164400 is output	A
DTCs P060B1C, P060B49 or P060B71 and P164400 are output	B
DTCs P061519 and P164400 are output	C

HINT:

If DTCs P060B1C, P060B49, P060B71 or P061519 and P164400 are output simultaneously, troubleshoot for DTC P060B1C, P060B49, P060B71 or P061519 first.

GO TO DTC P060B1C, P060B49 OR P060B71

GO TO DTC P061519

2.	CHECK HARNESS AND CONNECTOR (ENGINE STOP AND START ECU - ST NO. 1 RELAY)

(a) Disconnect the engine stop and start ECU connector.

(b) Remove the ST NO. 1 relay from the No. 1 engine room relay block and No. 1 junction block assembly.

(d) Disconnect the park/neutral position switch assembly connector.

(e) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Condition	Specified Condition
A34-21 (STA) - 2 (ST NO. 1 relay)	Always	Below 1 Ω
A34-21 (STA) or 2 (ST NO. 1 relay) - Body ground and other terminals	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

3.	CHECK HARNESS AND CONNECTOR (ENGINE STOP AND START ECU - PARK/NEUTRAL POSITION SWITCH ASSEMBLY)

(a) Disconnect the engine stop and start ECU connector.

(b) Disconnect the park/neutral position switch assembly connector.

(d) Remove the ST NO. 1 relay from the No. 1 engine room relay block and No. 1 junction block assembly.

(e) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Condition	Specified Condition
A34-21 (STA) - C31-9 (L)	Always	Below 1 Ω
A34-21 (STA) or C31-9 (L) - Body ground and other terminals	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

4.	INSPECT RELAY (ST NO. 1 RELAY)

(a) Inspect the ST NO. 1 relay.

Click here

REPLACE RELAY (ST NO. 1 RELAY)

5.	CHECK HARNESS AND CONNECTOR (ST NO. 1 RELAY - BODY GROUND)

(a) Remove the ST NO. 1 relay from the No. 1 engine room relay block and No. 1 junction block assembly.

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Condition	Specified Condition
1 (ST NO. 1 relay) - Body ground	Always	Below 1 Ω

REPAIR OR REPLACE HARNESS OR CONNECTOR

6.	CHECK HARNESS AND CONNECTOR (ENGINE STOP AND START ECU - ST NO. 2 RELAY)

(a) Disconnect the engine stop and start ECU connector.

(b) Remove the ST NO. 2 relay from the No. 1 engine room relay block and No. 1 junction block assembly.

(d) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Condition	Specified Condition
A34-23 (STA2) - 2 (ST NO. 2 relay)	Always	Below 1 Ω
A34-23 (STA2) or 2 (ST NO. 2 relay) - Body ground and other terminals	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

7.	INSPECT RELAY (ST NO. 2 RELAY)

(a) Inspect the ST NO. 2 relay.

Click here

REPLACE RELAY (ST NO. 2 RELAY)

8.	CHECK HARNESS AND CONNECTOR (ST NO. 2 RELAY - BODY GROUND)

(a) Remove the ST NO. 2 relay from the No. 1 engine room relay block and No. 1 junction block assembly.

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Condition	Specified Condition
1 (ST NO. 2 relay) - Body ground	Always	Below 1 Ω

REPLACE ENGINE STOP AND START ECU

REPAIR OR REPLACE HARNESS OR CONNECTOR