DTC P1C77-79: Engine Failed to Start Mechanical Linkage Failure [08/2023 - ]: Procedure

Pre-procedure1

1. Make sure that the shift lever is in P position.
2. Lift up the vehicle.

   Procedure1

3. Turn the crankshaft pulley using hand tools to check if the crankshaft can rotate smoothly.
   WARNING:

   Do not turn the ignition switch to ON (READY) while performing this inspection. Be sure to turn the ignition switch off before performing this inspection, to prevent the engine from starting.

   NOTE:

   Engine compression causes resistance when turning the crankshaft pulley. Check if the crankshaft rotates smoothly (or if it is locked) by manually applying sufficient torque to turn the crankshaft pulley. The torque required to turn the crankshaft pulley should be the same as for a known good vehicle of the same type.

   OK

   The crankshaft rotates smoothly.

   Result

   Proceed to
   OK
   NG

   Post-procedure1

4. Lower the vehicle.

Result: 

NG 

See step  6

Result: 

OK 

See step  2

Pre-procedure1

1. None.

   Procedure1

2. Clear the DTCs.

   Powertrain > Hybrid Control > Clear DTCs 

   Powertrain > Engine > Clear DTCs 

   Result

   Proceed to
   NEXT

   Post-procedure1

3. Turn the ignition switch off.

Result: 

NEXT 

See step  3

Pre-procedure1

1. Turn the ignition switch to ON (READY).

   Procedure1

2. Read the Data List.

   Powertrain > Hybrid Control > Data List 

   Tester Display
   Engine Speed
   Generator Revolution

   1. While the READY indicator is on, depress the accelerator pedal for 10 seconds.

      OK

      "Generator Revolution" is approximately 3.6 times "Engine Speed".

      HINT: 

      • If the engine does not race and DTC P3147-79 (Transmission system) is output or generator (MG1) operates but the engine does not crank, replace the hybrid vehicle transaxle assembly.
      • Refer to the graph for Data List confirmation of "Generator Revolution" and "Engine Speed".

      Data List	Engine Speed	Generator Revolution
      Reference Value	Approximately 1000 rpm	Approximately 3600 rpm
      	Approximately 1500 rpm	Approximately 5400 rpm
      	Approximately 2500 rpm	Approximately 9000 rpm

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Result

      Proceed to
      OK
      NG

   Post-procedure1

3. Turn the ignition switch off.

Result: 

NG 

REPLACE HYBRID VEHICLE TRANSAXLE ASSEMBLY. Refer to  REMOVAL [08/2023 - 10/2024]  , or refer to  REMOVAL [10/2024 - ] 

Result: 

OK 

See step  4

Pre-procedure1

1. Turn the ignition switch to ON (READY).

   Procedure1

2. Depress the brake pedal, move the shift lever to D, and release the brake pedal.

   OK

   The wheels turn (the vehicle creeps forward).

   Result

   Proceed to
   OK
   NG

   Post-procedure1

3. Turn the ignition switch off.

Result: 

NG 

REPLACE HYBRID VEHICLE TRANSAXLE ASSEMBLY. Refer to  REMOVAL [08/2023 - 10/2024]  , or refer to  REMOVAL [10/2024 - ] 

Result: 

OK 

See step  5

Pre-procedure1

1. Turn the ignition switch to ON (READY).

   Procedure1

2. Read the Data List.

   Powertrain > Hybrid Control > Data List 

   Tester Display
   Engine Speed
   Generator Revolution
   Motor Revolution

   1. Move the shift lever to D.
   2. Fully depress the accelerator pedal when the vehicle speed is 10 km/h (6 mph) or more.
      NOTE:

      Perform this test only in an appropriate safe location, in accordance with all local laws.

   3. Calculate the difference between the value of "Engine Speed" and "(0.28 x Generator Revolution) + (0.19 x Motor Revolution)".

      Result

      Result	Proceed to
      The absolute value of the difference is less than 500 rpm.	A
      The absolute value of the difference is 500 rpm or more continuously for 1 second.	B

   Post-procedure1

3. Turn the ignition switch off.

Result: 

A 

REPLACE HYBRID VEHICLE TRANSAXLE ASSEMBLY. Refer to  REMOVAL [08/2023 - 10/2024]  , or refer to  REMOVAL [10/2024 - ] 

Result: 

B 

REPLACE TRANSMISSION INPUT DAMPER ASSEMBLY. Refer to  REMOVAL [08/2023 - ] 

Pre-procedure1

1. Lift up the vehicle.
2. Move the shift lever to N.

   Procedure1

3. Turn the crankshaft pulley using hand tools to check if the crankshaft can rotate smoothly.
   WARNING:

   Do not turn the ignition switch to ON (READY) while performing this inspection. Be sure to turn the ignition switch off before performing this inspection, to prevent the engine from starting.

   NOTE:

   Engine compression causes resistance when turning the crankshaft pulley. Check if the crankshaft rotates smoothly (or if it is locked) by manually applying sufficient torque to turn the crankshaft pulley. The torque required to turn the crankshaft pulley should be the same as for a known good vehicle of the same type.

   OK

   The crankshaft rotates smoothly.

   Result

   Proceed to
   OK
   NG

   Post-procedure1

4. Move the shift lever to P.
5. Lower the vehicle.

Result: 

OK 

REPLACE HYBRID VEHICLE TRANSAXLE ASSEMBLY. Refer to  REMOVAL [08/2023 - 10/2024]  , or refer to  REMOVAL [10/2024 - ] 

Result: 

NG 

REPAIR OR REPLACE ENGINE