P0731-871

L110F HYBRID VEHICLE CONTROL: HYBRID CONTROL SYSTEM: P0731-871: Gear 1 Incorrect Ratio

DTC P0731-871 - Gear 1 Incorrect Ratio

DESCRIPTION

The hybrid vehicle control ECU uses the B1 and B2 brakes in the hybrid vehicle transmission assembly to switch between low and high gear.
Shifting control is performed using the line pressure circuit, B1 circuit, and B2 circuit. The hybrid vehicle control ECU detects abnormal line pressure by monitoring the operation of the fluid pressure switch in each circuit.
HINT: Although the DTC title indicates an incorrect gear ratio, DTC P0731-871 relates to a malfunction of the B2 hydraulic circuit.

HINT:
- The preceding timing chart is for the first "Control the Shift Position" active test. The chart will differ for the second or later "Control the Shift Position" active test.
- If "Hi" is selected in the first "Control the Shift Position" active test, it may take more time to shift to "Hi".

HINT: ST-on is a state that occurs when the READY indicator in the combination meter blinks after the power switch is pressed with the brake pedal depressed.

WIRING DIAGRAM

INSPECTION PROCEDURE

PROCEDURE

1. CHECK DTC OUTPUT (HV)
(a) Connect the intelligent tester or Techstream to the DLC3.
(b) Turn the power switch on (IG).
(c) Select the following menu items:
(1) Intelligent tester - Select: DIAGNOSIS / OBD/MOBD / HV ECU / DTC INFO / CURRENT CODES.
(2) Techstream - Select: Powertrain / Hybrid Control / Trouble Codes.
(d) Check if DTCs are output.
Result:

B -- GO TO DTC CHART
A -- Continue to next step.
2. CHECK CONNECTOR CONNECTION CONDITION (HYBRID VEHICLE CONTROL ECU CONNECTOR)

(a) Check the connections of the hybrid vehicle control ECU connectors.
OK:
The connectors are connected securely and there are no contact problems.
NG -- CONNECT SECURELY
OK -- Continue to next step.
3. CHECK CONNECTOR CONNECTION CONDITION (TRANSMISSION WIRE CONNECTOR)

(a) Check the connection of the transmission wire connector.
OK:
The connector is connected securely and there are no contact problems.
NG -- CONNECT SECURELY
OK -- Continue to next step.
4. CHECK HYBRID VEHICLE TRANSMISSION ASSEMBLY (SL1 SOLENOID VALVE, SL2 SOLENOID VALVE AND PRESSURE SWITCH 2)

(a) Disconnect connector E55 from the hybrid vehicle control ECU.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:

Result:

C -- CHECK HARNESS AND CONNECTOR (HYBRID VEHICLE CONTROL ECU - TRANSMISSION WIRE)
B -- CHECK HARNESS AND CONNECTOR (HYBRID VEHICLE CONTROL ECU - TRANSMISSION WIRE)
A -- Continue to next step.
5. READ VALUE USING INTELLIGENT TESTER OR TECHSTREAM (B2 OIL PRESS)

(a) Connect connector E55 to the hybrid vehicle control ECU.
(b) Disconnect the transmission wire connector.
(c) Turn the power switch on (IG).
NOTE: Turning the power switch on (IG) with the hybrid vehicle control ECU connector disconnected causes other DTCs to be stored. Clear the DTCs after performing this inspection.
(d) Select the following menu items:
(1) Intelligent tester - Select: DIAGNOSIS / OBD/MOBD / HV ECU / DATA LIST / B2 OIL PRESS.
(2) Techstream - Select: Powertrain / Hybrid Control / Data List / B2 Oil Pressure.
(e) Read the data list.
OK:

Intelligent Tester:

Techstream:

NG -- CHECK HARNESS AND CONNECTOR (HYBRID VEHICLE CONTROL ECU - TRANSMISSION WIRE)
OK -- Continue to next step.
6. CLEAR DTC
(a) Select the following menu items:
(1) Intelligent tester - Select: DIAGNOSIS / OBD/MOBD / HV ECU / DTC INFO / CURRENT CODES.
(2) Techstream - Select: Powertrain / Hybrid Control / Trouble Codes.
(b) Read and record the DTCs and freeze frame data.
(c) Select the following menu items:
(1) Intelligent tester - Select: DIAGNOSIS / OBD/MOBD / HV ECU / DTC INFO / CLEAR CODES.
(2) Techstream - Select: Powertrain / Hybrid Control / Trouble Codes.
(d) Clear DTCs and freeze frame data.
NEXT -- Continue to next step.
7. SIMULATION TEST
(a) Turn the power switch on (READY).
(b) Select the following menu items:
(1) Intelligent tester - Select: DIAGNOSIS / OBD/MOBD / HV ECU / ACTIVE TEST / SHIFT.
(2) Techstream - Select: Powertrain / Hybrid Control / Active Test / Control the Shift Position.
(c) Select the following menu items:
(1) Intelligent tester - Select: USER DATA / B1 OIL PRESS, B2 OIL PRESS, LINE PRESS, LINE PRESS SOL.
(2) Techstream - Select: All Data / B1 Oil Pressure, B2 Oil Pressure, Line Pressure, Line Pressure Solenoid.
(d) Perform the "Control the Shift Position" active test.
OK:

Intelligent Tester:

Techstream:

(e) Switch the shift position between "Lo" and "Hi" several times using the "Control the Shift Position" active test. Make sure that there is no abnormal data in the data list.
OK:
There is no abnormal data in the data list.
NOTE: Transmission system DTCs may be set if the "Control the Shift Position" active test is cancelled before it is completed.

NG -- REPLACE HYBRID VEHICLE TRANSMISSION ASSEMBLY
OK -- Continue to next step.
8. CHECK FOR INTERMITTENT PROBLEMS
(a) Check for intermittent problems. Check For Intermittent Problems

NG -- REPAIR OR REPLACE MALFUNCTIONING PARTS, COMPONENT AND AREA
OK -- Continue to next step.
9. CHECK FLUID LEAKS
(a) Check for fluid leaks from the hybrid vehicle transmission assembly.
OK:
There are no fluid leaks.
NG -- REPAIR OR REPLACE HYBRID VEHICLE TRANSMISSION ASSEMBLY
OK -- Continue to next step.
10. CHECK CONNECTOR CONNECTION CONDITION (PB2 OIL PRESSURE SWITCH)

(a) Remove the oil strainer assembly Components.
(b) Check the connection of the PB2 oil pressure switch connector.
Result:
The connector is connected securely and there are no contact problems.
NG -- CONNECT SECURELY
OK -- Continue to next step.
11. CHECK HARNESS AND CONNECTOR (TRANSMISSION WIRE)

(a) Disconnect the transmission wire connector.
(b) Disconnect the connector from the PB2 oil pressure switch.
(c) Turn the power switch on (IG).
(d) Measure the voltage according to the value(s) in the table below.
Standard voltage:

NOTE: Turning the power switch on (IG) with the transmission wire connector disconnected causes other DTCs to be stored. Clear the DTCs after performing this inspection.
(e) Turn the power switch off.

(f) Measure the resistance according to the value(s) in the table below.
Standard resistance (Check for open):

Standard resistance (Check for short):

NG -- REPLACE TRANSMISSION WIRE
OK -- REPLACE PB2 OIL PRESSURE SWITCH
12. CHECK HARNESS AND CONNECTOR (HYBRID VEHICLE CONTROL ECU - TRANSMISSION WIRE)

(a) Disconnect the transmission wire connector and disconnect connector E55 from the hybrid vehicle control ECU.
(b) Turn the power switch on (IG).
(c) Measure the voltage according to the value(s) in the table below.
Standard voltage :

NOTE: Turning the power switch on (IG) with the hybrid vehicle control ECU connector disconnected causes other DTCs to be stored. Clear the DTCs after performing this inspection.
(d) Turn the power switch off.
(e) Measure the resistance according to the value(s) in the table below.
Standard resistance (Check for open):

Standard resistance (Check for short):

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
13. CHECK CONNECTOR CONNECTION CONDITION (PB2 OIL PRESSURE SWITCH)

(f) Measure the resistance according to the value(s) in the table below.
Standard resistance (Check for open):

Standard resistance (Check for short):

NG -- REPLACE TRANSMISSION WIRE
OK -- REPLACE PB2 OIL PRESSURE SWITCH
15. CHECK HARNESS AND CONNECTOR (HYBRID VEHICLE CONTROL ECU - TRANSMISSION WIRE)

(a) Disconnect the transmission wire connector.
(b) Turn the power switch on (IG).
(c) Measure the voltage according to the value(s) in the table below.
Standard voltage :

Standard resistance (Check for short):

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE HYBRID VEHICLE TRANSMISSION ASSEMBLY
16. CHECK HARNESS AND CONNECTOR (HYBRID VEHICLE CONTROL ECU - TRANSMISSION WIRE)

Standard resistance (Check for short):

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE HYBRID VEHICLE CONTROL ECU