Last Modified: 01-30-2024 6.11:8.1.0 Doc ID: RM100000002EMA8
Model Year Start: 2024 Model: RAV4 Prod Date Range: [10/2023 -           ]
Title: STOP AND START: STOP AND START SYSTEM: P164400; ECU Malfunction (Starter Circuit); 2024 MY RAV4 [10/2023 -        ]

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.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Warning Indicate

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).
  • Wire harness or connector
  • ST NO. 1 relay
  • Engine stop and start ECU

Comes on

Does not come on

SAE Code: P1644

MONITOR STRATEGY

Related DTCs

P1644: Engine stop and start ECU internal starter relay circuit functional

Required Sensors/Components (Main)

Engine stop and start ECU

Required Sensors/Components (Related)

-

Frequency of Operation

Continuous

Duration

1 second: Case2

0.2 seconds: Case1, Case3, Case4, Case5, Case6, Case7

MIL Operation

Immediate

Sequence of Operation

None

TYPICAL ENABLING CONDITIONS

All

All of the following conditions are met

-

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

A/D converter fail (P060B)

Not detected

Case1

All of the following conditions are met

-

Engine stop and start ECU internal high side switch for starter relay

OFF

Engine stop and start ECU internal low side switch for starter relay

OFF

Engine stop and start ECU internal limit switch for starter relay

OFF

Engine stop and start ECU starter relay terminal voltage level

High

Case2

All of the following conditions are met

-

Engine stop and start ECU internal high side switch for starter relay

OFF

Engine stop and start ECU internal low side switch for starter relay

OFF

Engine stop and start ECU internal limit switch for starter relay

OFF

Engine stop and start ECU starter relay terminal voltage level

Low

Case3

All of the following conditions are met

-

Engine stop and start ECU internal starter relay circuit check*

Activated

Engine stop and start ECU internal high side switch for starter relay

OFF

Engine stop and start ECU internal low side switch for starter relay

OFF

Engine stop and start ECU internal limit switch for starter relay

ON

Engine stop and start ECU starter relay terminal voltage level

Low

Case4

All of the following conditions are met

-

Engine stop and start ECU internal starter relay circuit check*

Activated

Engine stop and start ECU internal high side switch for starter relay

ON

Engine stop and start ECU internal low side switch for starter relay

OFF

Engine stop and start ECU internal limit switch for starter relay

ON

Case5

All of the following conditions are met

-

Engine stop and start ECU internal starter relay circuit check*

Activated

Engine stop and start ECU internal high side switch for starter relay

OFF

Engine stop and start ECU internal low side switch for starter relay

ON

Engine stop and start ECU internal limit switch for starter relay

ON

Engine stop and start ECU starter relay terminal voltage level

Low

Case6

All of the following conditions are met

-

Engine stop and start ECU internal high side switch for starter relay

ON

Engine stop and start ECU internal low side switch for starter relay

ON

Starter relay overcurrent

Not detected

Case7

Engine stop and start ECU internal high side switch for starter relay

OFF

*: All of the following conditions are met

-

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

Battery voltage

8 V or higher

A/D converter fail (P060B)

Not detected

Engine stop and start ECU internal starter relay circuit fail (P1644)

Not detected

Engine stop and start ECU processer fail (P0606)

Not detected

Lost communication with skid control ECU (brake actuator assembly) (U0129)

Not detected

Starter

OFF

Engine

Running

Fuel cut

OFF

One of the following conditions (a), (b) or (c) is met

-

(a) Shift position

D range

(b) Shift position

R range

(c) Shift position

S range

Vehicle speed

7 to 15 km/h (4.3 to 9.3 mph)

Engine stop and start ECU starter relay voltage

Higher than [Battery voltage x 0.44] V, and less than [Battery voltage x 0.88] V

Engine stop and start ECU internal high side switch for starter relay

OFF

Engine stop and start ECU internal low side switch for starter relay

OFF

Time after engine stop and start ECU internal limit switch for starter relay OFF to ON

0.3 seconds or more

Time after engine stop and start ECU internal high side switch for starter relay ON to OFF

0.05 seconds or more

Engine stop and start ECU internal limit switch for starter relay

ON

Time after engine stop and start ECU internal low side switch for starter relay ON to OFF

0.05 seconds or more

Time after engine stop and start ECU internal limit switch for starter relay ON to OFF

0.05 seconds or more

TYPICAL MALFUNCTION THRESHOLDS

Case 1, Case2, Case5

Engine stop and start ECU starter relay voltage

Higher than [Battery voltage x 0.44] V

Case 3

Either of the following conditions (a) or (b) is met

-

(a) Engine stop and start ECU starter relay voltage

[Battery voltage x 0.44] V or less

(b) Engine stop and start ECU starter relay voltage

[Battery voltage x 0.88] V or higher

Case 4

Engine stop and start ECU starter relay voltage

Less than [Battery voltage x 0.88] V

Case 6

Engine stop and start ECU starter relay terminal voltage level

Low

Case 6

Starter relay overcurrent

Detected

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.
  • When clearing the permanent DTCs, refer to the "CLEAR PERMANENT DTC" procedure.

    Click here 2024 MY RAV4 [10/2023 -        ]; STOP AND START: STOP AND START SYSTEM: DTC CHECK / CLEAR

  • When clearing the permanent DTCs, do not disconnect the cable from the battery terminal or attempt to clear the DTCs during this procedure, as doing so will clear the universal trip and normal judgment histories.

CONFIRMATION AFTER TROUBLESHOOTING

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream 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

Click here 2024 MY RAV4 [10/2023 -        ]; STOP AND START: STOP AND START SYSTEM: OPERATION CHECK

WIRING DIAGRAM

Refer to DTC P061511.

Click here 2024 MY RAV4 [10/2023 -        ]; STOP AND START: STOP AND START SYSTEM: P061511; Starter Relay Circuit Short to Ground+

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 2024 MY RAV4 [10/2023 -        ]; STOP AND START: STOP AND START SYSTEM: REGISTRATION

  • 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 2024 MY RAV4 [10/2023 -        ]; STOP AND START: STOP AND START SYSTEM: REGISTRATION

  • 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 2024 MY RAV4 [10/2023 -        ]; STOP AND START: STOP AND START SYSTEM: REGISTRATION

  • When the engine stop and start ECU or oil pump with solenoid assembly is replaced, check the oil pump with solenoid assembly.

    Click here 2024 MY RAV4 [10/2023 -        ]; STOP AND START: STOP AND START SYSTEM: REGISTRATION

  • 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 2024 MY RAV4 [10/2023 -        ]; STOP AND START: STOP AND START SYSTEM: P060B1C,P060B49,P060B71; Analog to Digital Converter Circuit Voltage Out of Range

  • 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 2024 MY RAV4 [10/2023 -        ]; STOP AND START: STOP AND START SYSTEM: P061511; Starter Relay Circuit Short to Ground

  • 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.

    Click here 2024 MY RAV4 [10/2023 -        ]; STOP AND START: STOP AND START SYSTEM: FREEZE FRAME DATA

  • 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 2024 MY RAV4 [10/2023 -        ]; STOP AND START: STOP AND START SYSTEM: DTC CHECK / CLEAR

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.

(c) Turn the Techstream 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.

B

GO TO DTC P060B1C, P060B49 OR P060B71

C

GO TO DTC P061511

A

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.

(c) Disconnect the certification ECU (smart key ECU assembly) connector. (w/ Smart Key System)

(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

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

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.

(c) Disconnect the certification ECU (smart key ECU assembly) connector. (w/ Smart Key System)

(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

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

4.

INSPECT RELAY (ST NO. 1 RELAY)

(a) Inspect the ST NO. 1 relay.

Click here 2022 - 2024 MY RAV4 [12/2021 -        ]; A25A-FKS (STARTING): RELAY: INSPECTION+

NG

REPLACE RELAY (ST NO. 1 RELAY)

OK

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

OK

REPLACE ENGINE STOP AND START ECU

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR