Lexus NX manuals

Lexus NX: Hybrid Battery Precharge Contactor Circuit Stuck Closed (P0AE2-773)

Lexus NX Service Manual / Engine & Hybrid System / 2ar-fxe (hybrid / Battery Control) / Hybrid Control System / Hybrid Battery Precharge Contactor Circuit Stuck Closed (P0AE2-773)

DTC SUMMARY

MALFUNCTION DESCRIPTION

The hybrid vehicle control ECU detects a stuck closed malfunction of a precharge relay stuck malfunction on the HV battery negative side.

The cause of this malfunction may be one of the following:

Inside of inverter voltage sensor (VH) circuit malfunction
  • Voltage sensor (VH) malfunction
  • Motor generator control ECU (MG ECU) malfunction
  • Communication (wire harness) malfunction
High voltage system malfunction
  • Hybrid battery junction block assembly malfunction

DESCRIPTION

Refer to the description for DTC P0AE6-225.

Click here

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Warning Indicate

P0AE2-773

Hybrid Battery Precharge Contactor Circuit Stuck Closed

SMRP (precharge relay) is stuck closed due to a mechanical malfunction or other malfunction.

(2 trip detection logic)
  • Hybrid battery junction block assembly
  • Inverter with converter assembly

Does not come on

Master Warning Light:

Comes on
Related Data List

DTC No.

Data List

P0AE2-773
  • VL-Voltage before Boosting
  • Power Resource VB

The following items can be helpful when performing repairs:

Data List
  • SMRP Status
  • SMRB Status
  • SMRG Status

WIRING DIAGRAM

Refer to the wiring diagram for the HV battery high-voltage line circuit.

Click here

CAUTION / NOTICE / HINT

CAUTION:

  • When troubleshooting DTC P0AE2-773, use either a tool wrapped with vinyl insulation tape or an insulated tool. (It is extremely dangerous when a high-voltage charge passes through a non-insulated tool causing a short.)
  • Before inspecting the high-voltage system or disconnecting the low voltage connector of the inverter with converter assembly, take safety precautions such as wearing insulated gloves and removing the service plug grip to prevent electrical shocks. After removing the service plug grip, put it in your pocket to prevent other technicians from accidentally reconnecting it while you are working on the high-voltage system.
  • After removing the service plug grip, wait for at least 10 minutes before touching any of the high-voltage connectors or terminals. After waiting for 10 minutes, check the voltage at the terminals in the inspection point in the inverter with converter assembly. The voltage should be 0 V before beginning work.

    Click here

    HINT:

    Waiting for at least 10 minutes is required to discharge the high-voltage capacitor inside the inverter with converter assembly.

NOTICE:

After turning the power switch off, waiting time may be required before disconnecting the cable from the negative (-) auxiliary battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) auxiliary battery terminal notices before proceeding with work.

Click here

HINT:

After the repair, clear the DTCs, perform the following procedure and check that the same DTC (including pending DTC) is not output.

  1. Turn the power switch off and wait for 30 seconds or more.
  2. Turn the power switch on (READY) and wait for 30 seconds or more.
  3. Turn the power switch off and wait for 60 seconds or more.

PROCEDURE

1.

CHECK DTC OUTPUT (HYBRID CONTROL)

(a) Connect the Techstream to the DLC3.

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

(c) Enter the following menus: Powertrain / Hybrid Control / Trouble Codes.

(d) Check for DTCs.

Powertrain > Hybrid Control > Trouble Codes

Result

Proceed to

P0AE2-773 only is output, or DTCs except the ones in the table below are also output.

A

Any of the following DTCs including pending DTCs are also output.

B

Malfunction Content

Relevant DTC

Microcomputer malfunction

P0A1A-151, 658, 791

Generator Control Module

P0A1B-786, 794

Drive Motor "A" Control Module

P0A1D-148

Hybrid Powertrain Control Module

P1C2A-155

Generator A/D Converter Circuit

P1CA6-156

Generator Control Module Malfunction

P1CA7-193

Drive Motor Control Module Malfunction

P1CAC-200

Generator Position Sensor Angle Malfunction

P1CAD-168

Drive Motor "A" Position Sensor Angle Malfunction

P1CAF-792

Generator Position Sensor REF Signal Cycle Malfunction

P1CB0-795

Drive Motor "A" Position Sensor REF Signal Cycle Malfunction

P1CB2-793

Generator Position Sensor REF Signal Stop Malfunction

P1CB3-796

Drive Motor "A" Position Sensor REF Signal Stop Malfunction

P2511-149

HV CPU Power Relay Sense Circuit Intermittent No Continuity

P3133-659

Communication Error from Generator to Drive Motor "A"

P3134-661

Communication Error from Drive Motor "A" to Generator

P324E-788

MG-ECU Power Relay Intermittent Circuit

Power source circuit malfunction

P06B0-163

Sensor Power Supply "A" Circuit / Open

P06D6-511

Sensor Reference Voltage "F" Circuit / Open

P06E6-164

Sensor Power Supply "C" Circuit / Open

P1C73-512

Sensor Standard Voltage "F" Circuit / Open

Communication system malfunction

U0110 (all INF codes)*1

Lost Communication with Drive Motor Control Module "A"

Sensor and actuator circuit malfunction

P0A3F-243

Drive Motor "A" Position Sensor Circuit

P0A40-500

Drive Motor "A" Position Sensor Circuit Range / Performance

P0A41-245

Drive Motor "A" Position Sensor Circuit Low

P0A4B-253

Generator Position Sensor Circuit

P0A4C-513

Generator Position Sensor Circuit Range / Performance

P0A4D-255

Generator Position Sensor Circuit Low

P0AE0-228

Hybrid Battery Negative Contactor Control Circuit High

P0AE7-224

Hybrid Battery Precharge Contactor Control Circuit High

P0C76-523

Hybrid Battery System Discharge Time Too Long

System malfunction

P0AA4-232

Hybrid Battery Negative Contactor Circuit Stuck Closed

P0CA3-442

DC/DC Converter Step Up Voltage Performance

P0D2E-586

Drive Motor "A" Inverter Voltage Sensor Circuit Range / Performance

P0D2F-266

Drive Motor "A" Inverter Voltage Sensor Circuit Low

P0D30-267

Drive Motor "A" Inverter Voltage Sensor Circuit High

P3004-132

High Voltage Power Resource

HINT:

  • *1: If any INF codes are output for this DTC, refer to the corresponding diagnostic procedure.
  • P0AE2-773 may be output as a result of the malfunction indicated by the DTCs above.
    1. The chart above is listed in inspection order of priority.
    2. Check DTCs that are output at the same time by following the listed order. (The main cause of the malfunction can be determined without performing unnecessary inspections.)

(e) Turn the power switch off.

B

GO TO DTC CHART (HYBRID CONTROL SYSTEM)

A

2.

CHECK FREEZE FRAME DATA (HYBRID CONTROL)

(a) Connect the Techstream to the DLC3.

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

(c) Enter the following menus: Powertrain / Hybrid Control / Trouble Codes.

(d) Read the freeze frame data of DTC P0AE2-773.

HINT:

In the freeze frame data, read the item "VL-Voltage before Boosting".

Result

Proceed to

"VL-Voltage before Boosting" is 55 V or more.

A

"VL-Voltage before Boosting" is less than 55 V.

B

HINT:

If VH-Voltage after Boosting is output even when an off command is being sent to the system main relay (positive side), P0AE2-773 is output. If the difference between the "VL-Voltage before Boosting" and the "VH-Voltage after Boosting" is large, it is determined that there is an inverter (VH sensor) malfunction.

(e) Turn the power switch off.

B

REPLACE INVERTER WITH CONVERTER ASSEMBLY

A

3.

CHECK CONNECTOR CONNECTION CONDITION (HYBRID VEHICLE CONTROL ECU CONNECTOR)

Click here

OK

GO TO STEP 5

NG

4.

CONNECT SECURELY
NEXT

5.

CHECK CONNECTOR CONNECTION CONDITION (FLOOR WIRE CONNECTOR)

Click here

OK

GO TO STEP 7

NG

6.

CONNECT SECURELY
NEXT

7.

CHECK CONNECTOR CONNECTION CONDITION (NO. 2 HYBRID BATTERY PACK WIRE CONNECTOR)

Click here

Result

Proceed to

OK

A

NG (The connector is not connected securely.)

B

NG (The terminals are not making secure contact or are deformed, or water or foreign matter exists in the connector.)

C
A

GO TO STEP 10

C

GO TO STEP 9

B

8.

CONNECT SECURELY
NEXT

GO TO STEP 10

9.

REPAIR OR REPLACE HARNESS OR CONNECTOR
NEXT

10.

CHECK CONNECTOR CONNECTION CONDITION (HYBRID BATTERY JUNCTION BLOCK ASSEMBLY CONNECTOR)

Click here

OK

GO TO STEP 12

NG

11.

CONNECT SECURELY
NEXT

12.

CHECK GROUND WIRE CONNECTION CONDITION (SMR ACTIVATION LOW-VOLTAGE CIRCUIT)

Click here

OK

GO TO STEP 14

NG

13.

CONNECT SECURELY
NEXT

14.

CHECK HARNESS AND CONNECTOR (HYBRID VEHICLE CONTROL ECU - HYBRID BATTERY JUNCTION BLOCK ASSEMBLY)

CAUTION:

Be sure to wear insulated gloves.

(a) Check that the service plug grip is not installed.

NOTICE:

After removing the service plug grip, do not turn the power switch on (READY), unless instructed by the repair manual because this may cause a malfunction.

(b) Remove the No. 2 hybrid vehicle battery shield reinforcement.

Click here

(c) Disconnect the y1 hybrid battery junction block assembly connector.

(d) Disconnect the I115 hybrid vehicle control ECU connector.

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

Standard Resistance (Check for Open):

Tester Connection

Condition

Specified Condition

I115-3 (SMRP) - y1-3 (SMRP)

Power switch off

Below 1 Ω

Standard Resistance (Check for Short):

Tester Connection

Condition

Specified Condition

I115-3 (SMRP) and y1-3 (SMRP) - Body ground and other terminals

Power switch off

10 kΩ or higher

*a

Rear view of wire harness connector

(to Hybrid Vehicle Control ECU)

*b

Rear view of wire harness connector

(to hybrid Battery Junction Block Assembly)

(f) Reconnect the I115 hybrid vehicle control ECU connector.

(g) Reconnect the y1 hybrid battery junction block assembly connector.

(h) Install the No. 2 hybrid vehicle battery shield reinforcement.

OK

GO TO STEP 16

NG

15.

REPAIR OR REPLACE HARNESS OR CONNECTOR
NEXT

16.

CHECK HARNESS AND CONNECTOR (HYBRID BATTERY JUNCTION BLOCK ASSEMBLY - BODY GROUND)

Click here

OK

GO TO STEP 18

NG

17.

REPAIR OR REPLACE HARNESS OR CONNECTOR
NEXT

18.

INSPECT HV BATTERY JUNCTION BLOCK ASSEMBLY (SMRP)

CAUTION:

Be sure to wear insulated gloves.

(a) Check that the service plug grip is not installed.

NOTICE:

After removing the service plug grip, do not turn the power switch on (READY), unless instructed by the repair manual because this may cause a malfunction.

(b) Remove the No. 2 hybrid vehicle battery shield reinforcement.

Click here

(c) Disconnect the y1 hybrid battery junction block assembly connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

y1-3 (SMRP) - y1-2 (GND)

-40 to 80°C (-40 to 176°F)

140 to 290 Ω

*a

Component without harness connected

(Hybrid Battery Junction Block Assembly)

(e) Reconnect the y1 hybrid battery junction block assembly connector.

(f) Install the No. 2 hybrid vehicle battery shield reinforcement.

NG

GO TO STEP 21

OK

19.

CHECK HV BATTERY JUNCTION BLOCK ASSEMBLY (SMRP)

CAUTION:

Be sure to wear insulated gloves.

(a) Check that the service plug grip is not installed.

NOTICE:

After removing the service plug grip, do not turn the power switch on (READY), unless instructed by the repair manual because this may cause a malfunction.

(b) Remove the No. 2 hybrid vehicle battery shield reinforcement.

Click here

(c) Disconnect the 2 high voltage cable connectors of the HV battery from the hybrid battery junction block assembly.

(d) Disconnect the No. 2 frame wire from the hybrid battery junction block assembly.

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

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

t6-1 (CEI) - x3-1 (-)

Power switch off

10 kΩ or higher

HINT:

  • If a system main relay is stuck closed, inspect the hybrid battery junction block assembly without removing it from the vehicle, in order to keep the relay closed.
  • If the result of reading the freeze frame data is A, the hybrid battery junction block assembly must be replaced. Measuring resistance can determine that this is either a present or past malfunction.

*a

Component without harness connected

(Hybrid Battery Junction Block Assembly)

(g) Reconnect the 2 high voltage cable connectors of the HV battery.

(h) Reconnect the No. 2 frame wire to the hybrid battery junction block assembly.

(i) Install the No. 2 hybrid vehicle battery shield reinforcement.

NG

GO TO STEP 22

OK

20.

REPLACE HV BATTERY JUNCTION BLOCK ASSEMBLY

Click here

NEXT

GO TO STEP 23

21.

REPLACE HV BATTERY JUNCTION BLOCK ASSEMBLY

Click here

NEXT

GO TO STEP 23

22.

REPLACE HV BATTERY JUNCTION BLOCK ASSEMBLY

Click here

NEXT

23.

CHECK HYBRID VEHICLE CONTROL ECU (CHECK FOR NORMAL OPERATION)

Click here

Result

Proceed to

Difference between "Power Resource VB" and "VL-Voltage before Boosting" is always less than 100 V.

A

Difference between "Power Resource VB" and "VL-Voltage before Boosting" is 100 V or more.

B
A

END
B

REPLACE HYBRID VEHICLE CONTROL ECU AND HYBRID BATTERY JUNCTION BLOCK ASSEMBLY

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