Toyota Avalon (XX50) 2019-2022 Service & Repair Manual: Starter Relay Circuit Short to Battery (P061512)

DESCRIPTION

While the engine is being cranked, battery voltage is applied to terminal STA of the ECM.

If the ECM detects the starter control (STA) signal while the vehicle is being driven, it determines that there is a malfunction in the STA circuit. The ECM then illuminates the MIL and stores this DTC.

This monitor runs when the vehicle is driven at 20 km/h (12 mph) or more for 20 seconds or more.

MONITOR STRATEGY

TYPICAL ENABLING CONDITIONS

TYPICAL MALFUNCTION THRESHOLDS

CONFIRMATION DRIVING PATTERN

CAUTION:

When performing the confirmation driving pattern, obey all speed limits and traffic laws.

HINT:

• After repairs have been completed, clear the DTCs and then check that the vehicle has returned to normal by performing the following All Readiness check procedure.
• When clearing the permanent DTCs, refer to the Clear Permanent DTC procedure.

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1. Connect the Techstream to the DLC3.
2. Turn the engine switch on (IG) and turn the Techstream on.
3. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
4. Turn the engine switch off and wait for 2 minutes or more.
5. Turn the engine switch on (IG) and turn the Techstream on.
6. Start the engine.
7. Drive the vehicle for 20 seconds or more with the following conditions met [*1]:
   • Engine speed is 1000 rpm or more.
   • Vehicle speed is 20 km/h (12 mph) or more.

     HINT:

     [*1] : Normal judgment procedure.

     The normal judgment procedure is used to complete DTC judgment and also used when clearing permanent DTCs.

8. Stop the vehicle.
9. Enter the following menus: Powertrain / Transmission / Utility / All Readiness.
10. Input the DTC: P061512.
11. Check the DTC judgment result.

    Techstream Display	Description
    NORMAL	DTC judgment completed System normal
    ABNORMAL	DTC judgment completed System abnormal
    INCOMPLETE	DTC judgment not completed Perform driving pattern after confirming DTC enabling conditions
    N/A	Unable to perform DTC judgment Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit

    HINT:

    • If the judgment result shows NORMAL, the system is normal.
    • If the judgment result shows ABNORMAL, the system has a malfunction.
    • If the judgment result shows INCOMPLETE or N/A, perform the normal judgment procedure again.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

CAUTION:

• Strictly observe posted speed, limits, traffic laws and road conditions.
• Do not drive the vehicle with the cable of the Techstream contacting the pedals, shift lever or steering wheel.
• Driving the vehicle with the cable of the Techstream contacting these areas could impede vehicle control, resulting in a serious accident.

• Do not operate the Techstream while driving the vehicle.
• Operating the Techstream while driving the vehicle will prevent you from paying sufficient attention to vehicle surroundings, and could result in a serious accident.

NOTICE:

• Inspect the fuses for circuits related to this system before performing the following procedure.
• Perform the universal trip to clear permanent DTCs.

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• Perform registration and/or initialization when parts related to the automatic transaxle are replaced.

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PROCEDURE

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(c) Turn the Techstream on.

(d) Enter the following menus: Powertrain / Transmission / Data List / Starter SW.

(e) Read the Data List according to the display on the Techstream.

OK:

(f) Read the Data List according to the display on the Techstream while the vehicle is being driven with an engine speed of 1000 rpm or more at a vehicle speed of 20 km/h (12 mph) or more.

OK:

HINT:

If the result of either of the above is not as specified, proceed to the next step with the engine switch on (IG), the Techstream connected and Data List item "Starter SW" selected.

HINT:

If the starter assembly operates continuously when the engine switch is turned on (IG), proceed to the next step without reading the Data List item "Starter SW".

OK

SYMPTOMS SIMULATION AND DTC CHECK

NG

(a) Enter the following menus: Powertrain / Transmission / Data List / Starter SW.

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

(c) Read the Data List according to the display on the Techstream.

HINT:

• When the result of the above inspection is "The Data List item "Starter SW" does not change from ON", the ST relay is normal.
• DTCs may be stored during this inspection. Check for DTCs and clear them using the Techstream.

B

REPLACE ST RELAY

A

HINT:

The purpose of this step is to check for ST relay terminal voltage under abnormal conditions.

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

*1 No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly *2 ST Relay Holder

(b) Turn the engine switch on (IG).

(c) Measure the voltage between ST relay terminal 2 and body ground.

HINT:

• Make a note of the measured voltage as it will be necessary for inspecting the change in voltage in the next step. As the next step should be conducted under the same conditions, keep the engine switch on (IG) and do not install the ST relay.
• DTCs may be stored during this inspection. Check for DTCs and clear them using the Techstream.
• If any voltage was measured with the engine switch on (IG), one of the following malfunctions is suspected:
  • Short to +B in the circuit of a connected ECU or park/neutral position switch assembly.
  • Short to +B in the wire harness.

NEXT

(a) Disconnect the C53 park/neutral position switch assembly connector.

*1 No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly *2 ST Relay Holder

(b) Measure the voltage between ST relay terminal 2 and body ground and compare it to the voltage measured in the previous step.

HINT:

• If the voltage is the same before and after disconnecting the connector, the park/neutral position switch assembly is normal.
• DTCs may be stored during this inspection. Check for DTCs and clear them using the Techstream.

B

REPLACE PARK/NEUTRAL POSITION SWITCH ASSEMBLY

A

(a) Disconnect the A18 ECM connector.

*1 No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly *2 ST Relay Holder

(b) Measure the voltage between ST relay terminal 2 and body ground and compare it to the voltage measured in the previous step.

HINT:

• If the voltage is the same before and after disconnecting the connector, the ECM is normal.
• DTCs may be stored during this inspection. Check for DTCs and clear them using the Techstream.

B

GO TO STEP 7

A

(a) Disconnect the A18 ECM connector.

(b) Disconnect the C53 park/neutral position switch assembly connector.

(c) Disconnect the A10 certification ECU (smart key ECU assembly) connector.

(d) Remove the ST 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:

OK

CHECK SMART KEY SYSTEM (CHECK FOR STA TERMINAL VOLTAGE OF SMART KEY ECU ASSEMBLY)

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

(a) Replace the ECM.

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NEXT

PERFORM REGISTRATION