DTC P1378-00: Pre-ignition Detected [12/2021 - ]: Procedure

1. Read the DTCs.

   Powertrain > Engine > Trouble Codes 

   Result

   Result	Proceed to
   P1378-00 and other DTCs are output	A
   P1378-00 is output	B

   HINT: 

   If any DTCs other than P1378-00 are output, troubleshoot those DTCs first.

Result: 

A 

GO TO DTC CHART. Refer to  DIAGNOSTIC TROUBLE CODE CHART [12/2021 - ] 

Result: 

B 

See step  2

1. Using the GTS, confirm the vehicle conditions recorded in the freeze frame data which were present when the DTC was stored.

   HINT: 

   • Check the freeze frame data sets recorded the moment the DTC was stored and after the DTC was stored.
   • Using the freeze frame data, confirm the vehicle conditions when the DTC was stored, such as if the engine was idling with the shift lever in P, D or N or if the vehicle was being driven at a constant speed or accelerating.
   CONFIRMATION ITEM
   
   

   Vehicle Speed	Short FT Bank 1, Bank 2
   Engine Speed	Long FT Bank 1, Bank 2
   Vehicle Load	Fuel System Status Bank 1, Bank 2
   Coolant Temperature	Misfire Count Cylinder #1 to #6

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  3

Pre-procedure1

1. Start the engine.

   Procedure1

2. According to the freeze frame data, attempt to reproduce the vehicle conditions that were present when the DTC was stored and read the Data List.

   Powertrain > Engine > Data List 

   Tester Display
   Consecutive Prevention Cylinder #1 History 1
   Consecutive Prevention Cylinder #1 History 2
   Consecutive Prevention Cylinder #1 History 3
   Consecutive Prevention Cylinder #1 History 4
   Consecutive Prevention Cylinder #2 History 1
   Consecutive Prevention Cylinder #2 History 2
   Consecutive Prevention Cylinder #2 History 3
   Consecutive Prevention Cylinder #2 History 4
   Consecutive Prevention Cylinder #3 History 1
   Consecutive Prevention Cylinder #3 History 2
   Consecutive Prevention Cylinder #3 History 3
   Consecutive Prevention Cylinder #3 History 4
   Consecutive Prevention Cylinder #4 History 1
   Consecutive Prevention Cylinder #4 History 2
   Consecutive Prevention Cylinder #4 History 3
   Consecutive Prevention Cylinder #4 History 4
   Consecutive Prevention Cylinder #5 History 1
   Consecutive Prevention Cylinder #5 History 2
   Consecutive Prevention Cylinder #5 History 3
   Consecutive Prevention Cylinder #5 History 4
   Consecutive Prevention Cylinder #6 History 1
   Consecutive Prevention Cylinder #6 History 2
   Consecutive Prevention Cylinder #6 History 3
   Consecutive Prevention Cylinder #6 History 4
   Fuel Cut History 1
   Fuel Cut History 2
   Fuel Cut History 3
   Fuel Cut History 4

   Result

   Result	Proceed to
   Values are displayed for multiple consecutive prevention cylinder histories of a specific cylinder	A
   Values are displayed for multiple consecutive prevention cylinder histories of all cylinders	B

   HINT: 

   • If values are displayed for multiple consecutive prevention cylinder histories of a specific cylinder, check the value of freeze frame data items Misfire Count Cylinder #1 through #6. If the misfire count of that cylinder is high, the cylinder is malfunctioning.
   • If the vehicle conditions when the DTC was stored cannot be reproduced, read the value of freeze frame data items Misfire Count Cylinder #1 through #6 to determine if only a specific cylinder or all cylinders are malfunctioning.

   Post-procedure1

3. None

Result: 

B 

See step  6

Result: 

A 

See step  4

Refer to ON-VEHICLE INSPECTION [12/2021 - ]

HINT: 

• Interchange the ignition coil assembly and spark plug of the malfunctioning cylinder with those of a known good cylinder and according to the freeze frame data, check if the malfunctioning cylinder returns to normal.
• Read the Data List items Misfire Count Cylinder #1 to #6 while performing this procedure to determine which cylinder is malfunctioning.

Result

Result: 

A 

See step  25

Result: 

B 

See step  5

1. Check the power source circuit, wire harness and connectors.

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  25

Pre-procedure1

1. Start the engine.

   Procedure1

2. According to the freeze frame data, attempt to reproduce the vehicle conditions that were present when the DTC was stored and read the Data List.

   Powertrain > Engine > Data List 

   Tester Display
   Short FT B1S1
   Short FT B2S1
   Long FT B1S1
   Long FT B2S1

   Result

   Result	Proceed to
   The sum of the value of Short FT B1S1 and Long FT B1S1 is -20 % or more, and less than 20 %	A
   None of the above conditions are met	B

   HINT: 

   • If the vehicle conditions when the DTC was stored cannot be reproduced, read the value of freeze frame data items Short FT Bank 1, Bank 2 and Long FT Bank 1, Bank 2 to perform judgment.
   • "Total FT Bank 1" is used to detect an abnormal air fuel ratio. As the value of "Total FT Bank 1" is corrected by the ECM before it is displayed in the Data List, the displayed value may not be equal to the sum of the measured "Short FT B1S1" and "Long FT B1S1".
   • An abnormally lean or rich tendency can be checked by reading the following Data List items: A/F Learn Value Idle Bank 1, A/F Learn Value Low Bank 1, A/F Learn Value Mid No. 1 Bank 1, A/F Learn Value Mid No. 2 Bank 1, A/F Learn Value High Bank 1, A/F Learn Value Idle (Port) Bank 1, A/F Learn Value Low (Port) Bank 1, A/F Learn Value Mid No. 1 (Port) Bank 1, A/F Learn Value Mid No. 2 (Port) Bank 1 and A/F Learn Value High (Port) Bank 1.
   • The following may cause a lean air fuel ratio (an operating range in which the air fuel ratio learned value correction is +20% or more):
     1. Decrease in fuel injector assembly injection volume
     2. Decrease in mass air flow meter sub-assembly output (due to existence of foreign matter)
     3. Air leaks in intake system after mass air flow meter sub-assembly
     4. Decrease in fuel pressure (at fuel filter, fuel pump assembly, fuel main valve assembly or fuel suction plate sub-assembly)
   • On vehicles which the learning value for each operating range can be checked, if the value of "A/F Learn Value High Bank 1" or "A/F Learn Value High (Port) Bank 1" only is corrected to the positive side, a malfunction in the fuel system (clogging of the fuel pump assembly or fuel filter) is suspected.
   • On vehicles which the learning value for each operating range can be checked, if the value of "A/F Learn Value Idle Bank 1", "A/F Learn Value Low Bank 1" or "A/F Learn Value Low (Port) Bank 1" only is corrected to the positive side, an air leak after the mass air flow meter sub-assembly is suspected.
   • The following may cause a rich air fuel ratio (an operating range in which the air fuel ratio learned value correction is -20% or less):
     1. Increase in the fuel injector assembly injection volume
     2. Purge VSV system

   Post-procedure1

3. None

Result: 

B 

See step  12

Result: 

A 

See step  7

Pre-procedure1

1. Start the engine.

   Procedure1

2. According to the freeze frame data, attempt to reproduce the vehicle conditions that were present when the DTC was stored and read the Data List.

   Powertrain > Engine > Data List 

   Tester Display
   Short FT B1S1
   Short FT B2S1
   Long FT B1S1
   Long FT B2S1

   Result

   Result	Proceed to
   The sum of the value of Short FT B2S1 and Long FT B2S1 is -20 % or more, and less than 20 %	A
   None of the above conditions are met	B

   HINT: 

   • If the vehicle conditions when the DTC was stored cannot be reproduced, read the value of freeze frame data items Short FT Bank 2 and Long FT Bank 2 to perform judgment.
   • "Total FT Bank 2" is used to detect an abnormal air fuel ratio. As the value of "Total FT Bank 2" is corrected by the ECM before it is displayed in the Data List, the displayed value may not be equal to the sum of the measured "Short FT B2S1" and "Long FT B2S1".
   • An abnormally lean or rich tendency can be checked by reading the following Data List items: A/F Learn Value Idle Bank 2, A/F Learn Value Low Bank 2, A/F Learn Value Mid No. 1 Bank 2, A/F Learn Value Mid No. 2 Bank 2, A/F Learn Value High Bank 2, A/F Learn Value Idle (Port) Bank 2, A/F Learn Value Low (Port) Bank 2, A/F Learn Value Mid No. 1 (Port) Bank 2, A/F Learn Value Mid No. 2 (Port) Bank 2 and A/F Learn Value High (Port) Bank 2.
   • The following may cause a lean air fuel ratio (an operating range in which the air fuel ratio learned value correction is +20% or more):
     1. Decrease in fuel injector assembly injection volume
     2. Decrease in mass air flow meter sub-assembly output (due to existence of foreign matter)
     3. Air leaks in intake system after mass air flow meter sub-assembly
     4. Decrease in fuel pressure (at fuel filter, fuel pump assembly, fuel main valve assembly or fuel suction plate sub-assembly)
   • On vehicles which the learning value for each operating range can be checked, if the value of "A/F Learn Value High Bank 2" or "A/F Learn Value High (Port) Bank 2" only is corrected to the positive side, a malfunction in the fuel system (clogging of the fuel pump assembly or fuel filter) is suspected.
   • On vehicles which the learning value for each operating range can be checked, if the value of "A/F Learn Value Idle Bank 2", "A/F Learn Value Low Bank 2" or "A/F Learn Value Low (Port) Bank 2" only is corrected to the positive side, an air leak after the mass air flow meter sub-assembly is suspected.
   • The following may cause a rich air fuel ratio (an operating range in which the air fuel ratio learned value correction is -20% or less):
     1. Increase in the fuel injector assembly injection volume
     2. Purge VSV system

   Post-procedure1

3. None

Result: 

B 

See step  12

Result: 

A 

See step  8

1. Interview the customer for details about when oil maintenance was last performed and what brand of oil was used.
   1. Check whether the specified engine oil grade was used and that engine oil additives were not used.
   2. Perform an engine oil inspection (check the oil level and for dirt, etc.).

      Refer to ON-VEHICLE INSPECTION [12/2021 - ]

   OK

   No problem with the engine oil.

   HINT: 

   • Strong knocking due to pre-ignition may be due to ignition of atomized engine oil under certain conditions.
   • The risk of this occurring may be increased if the engine oil used is not the specified oil grade.
   • The risk of this occurring may be increased if engine oil additives have been used.
   • As strong knocking due to pre-ignition may be caused by multiple superimposed factors, even if the engine oil inspection result is NG, perform the following inspections after replacing the engine oil.

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  9

1. Interview the customer for details about what fuel they have used and smell the fuel to check for the following.
   • If the fuel smells like a mixture of gasoline and diesel fuel, etc.
   • If there is a possibility that diesel fuel may have be added by mistake.
   • If the malfunction started after refueling at an unfamiliar gas station.
   • If fuel additives have been used.

   HINT: 

   Even if any of the above conditions are met, if the engine is not malfunctioning, fill the fuel tank at a different gas station and check if the malfunction recurs.

   Result

   Result	Proceed to
   None of the above conditions are met and the engine is not malfunctioning	A
   One or more of the above conditions are met and the engine is malfunctioning	B

   HINT: 

   • Strong knocking due to pre-ignition may be caused by the type fuel used.
   • The risk of pre-ignition occurring may be increased depending on the ingredients of fuel additives used.
   • Even if no abnormalities are found in this inspection, if a malfunction occurs after the vehicle has been refueled, a problem with the fuel is suspected.

Result: 

B 

See step  11

Result: 

A 

See step  10

1. Check for accumulated deposits (carbon) and remove them. Deposits (carbon) may act as an ignition source if they become detached, leading to pre-ignition.

   HINT: 

   Strong knocking due to pre-ignition may be caused by detached deposits burning inside the cylinder.

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  25

1. Replace the fuel.

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  26

Pre-procedure1

1. Start the engine and warm it up until the engine coolant temperature is 75°C (167°F) or higher with all the accessories switched off and the shift lever in D.

   Procedure1

2. Read Mass Air Flow Sensor while the engine idling.

   Powertrain > Engine > Data List 

   Tester Display
   MAF Sensor Bank1
   MAF Sensor Bank2

   Result

   Result	Proceed to
   The value of MAF Sensor Bank1 is between 1.8 and 3.0 gm/sec and the value of MAF Sensor Bank2 is between 1.8 and 3.0 gm/sec	A
   None of the above conditions are met	B

   Post-procedure1

3. None

Result: 

B 

See step  23

Result: 

A 

See step  13

Pre-procedure1

1. Start the engine and warm it up until the engine coolant temperature is 75°C (167°F) or higher with all the accessories switched off and the shift lever in N.

   Procedure1

2. Read Mass Air Flow Sensor while maintaining an engine speed of 2000 rpm.

   Powertrain > Engine > Data List 

   Tester Display
   MAF Sensor Bank1
   MAF Sensor Bank2

   Result

   Result	Proceed to
   The value of MAF Sensor Bank1 is between 5.0 and 25.0 gm/sec and the value of MAF Sensor Bank2 is between 5.0 and 25.0 gm/sec	A
   None of the above conditions are met	B

   Post-procedure1

3. None

Result: 

B 

See step  23

Result: 

A 

See step  14

Pre-procedure1

1. Start the engine and warm it up until the engine coolant temperature is 75°C (167°F) or higher with all the accessories switched off and the shift lever in N.

   Procedure1

2. Read Mass Air Flow Sensor while maintaining an engine speed of 3000 rpm.

   Powertrain > Engine > Data List 

   Tester Display
   MAF Sensor Bank1
   MAF Sensor Bank2

   Result

   Result	Proceed to
   The value of MAF Sensor Bank1 is between 6.5 and 30.0 gm/sec and the value of MAF Sensor Bank2 is between 6.5 and 30.0 gm/sec	A
   None of the above conditions are met	B

   Post-procedure1

3. None

Result: 

B 

See step  23

Result: 

A 

See step  15

Pre-procedure1

1. Start the engine and warm it up until the engine coolant temperature is 75°C (167°F) or higher with all the accessories switched off.
2. Warm up the air fuel ratio sensor at an engine speed of 2500 rpm for 90 seconds.
3. Idle the engine.

   Procedure1

4. According to the display on the GTS, perform the Active Test and check the vehicle conditions when increasing and decreasing the fuel injection volume of port injection and direct injection.

   Powertrain > Engine > Active Test 

   Active Test Display
   D-4S (Injection Volume)

   Data List Display
   Injection Mode
   A/F (O2) Sensor Current B1S1
   A/F (O2) Sensor Current B2S1
   A/F (O2) Sensor Current B1S2
   A/F (O2) Sensor Current B2S2

   NOTE:

   • The air fuel ratio sensor (sensor 1) has an output delay of a few seconds and the air fuel ratio sensor (sensor 2) has a maximum output delay of approximately 20 seconds.
   • Read the output value immediately after warming up the air fuel ratio sensor (sensor 1) and air fuel ratio sensor (sensor 2) to avoid an inaccurate reading due to a sensor cooling.

   HINT: 

   • Increase and decrease the fuel injection volume of the port injection and direct injection simultaneously and check the vehicle condition.
   • The Control the Injection Volume for A/F Sensor operation lowers the fuel injection volume by 12.5% or increases the injection volume by 12.5%.

   Standard

   GTS Display (Sensor)	Injection Volume	Current
   A/F (O2) Sensor Current B1S1 A/F (O2) Sensor Current B2S1 (Air fuel ratio (sensor 1))	12.5%	Below -0.075 mA
   	-12.5%	More than 0.037 mA
   A/F (O2) Sensor Current B1S2 A/F (O2) Sensor Current B2S2 (Air fuel ratio (sensor 2))	12.5%	Below -0.86 mA
   	-12.5%	More than 0.33 mA

   Result

   Result	Proceed to
   Output current values are abnormal	A
   Malfunction disappears when fuel injection volume is increased	B
   Malfunction is still present when fuel injection volume is increased, even if output current values are normal	C

   Post-procedure1

5. None

Result: 

B 

See step  17

Result: 

C 

See step  18

Result: 

A 

See step  16

1. Replace the air fuel ratio sensor (sensor 1).

   Refer to REMOVAL [12/2021 - ]

   HINT: 

   Perform "Inspection After Repair" after replacing the air fuel ratio sensor (sensor 1).

   Refer to INITIALIZATION [12/2021 - ]

2. Replace the air fuel ratio sensor (sensor 2).

   Refer to REMOVAL [12/2021 - ]

   HINT: 

   Perform "Inspection After Repair" after replacing the air fuel ratio sensor (sensor 2).

   Refer to INITIALIZATION [12/2021 - ]

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  26

1. Replace the fuel injector assemblies of all cylinders.

   HINT: 

   Perform "Inspection After Repair" after replacing the fuel injector assembly.

   Refer to INITIALIZATION [12/2021 - ]

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  26

1. When performing the Active Test, check for an operating sound from the fuel pump assembly (for low pressure side).

   Powertrain > Engine > Active Test 

   Tester Display
   Activate the Circuit Relay (Brushless)

   OK

   Activate the Circuit Relay (Brushless)	Specified Condition
   ON	Operating sound heard
   OFF	Operating sound not heard

   Result

   Proceed to
   OK
   NG

Result: 

NG 

See step  24

Result: 

OK 

See step  19

1. Attach a fuel pressure gauge and check the fuel pressure when cranking the engine and after stopping the engine.

   Refer to PROCEDURE - Step 2

   Standard

   Vehicle State	Specified Condition
   Cranking engine	196 to 833 kPa (2.0 to 8.5 kgf/cm2 , 28 to 121 psi)
   5 minutes after stopping engine	98 kPa (1.0 kgf/cm2 , 14 psi) or higher

   HINT: 

   • If there is foreign matter such as iron particles on the fuel pump assembly (for low pressure side), remove it.
   • Make sure that there are no leaks from the fuel lines, signs of fuel leakage or fuel odors.
   • If the air fuel ratio becomes lean only when the engine is running under a high load and at a high engine speed, clogging of the fuel filter is suspected.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

See step  22

Result: 

OK 

See step  20

Pre-procedure1

1. Start the engine and warm it up until the engine coolant temperature is 75°C (167°F) or higher with all the accessories switched off.

   Procedure1

2. According to the display on the GTS, read the Data List with the following condition.
   • Shift position: P
   • A/C: Off
   • Engine warmed up
   • Engine Speed: 3000 rpm
   • Injection Mode: Direct

   Powertrain > Engine > Data List 

   Tester Display
   Engine Speed
   Fuel Pressure (High)
   Injection Mode

   Result

   Result	Proceed to
   The value of Fuel Pressure (High) is between 2800 and 20000 kPag	A
   None of the above conditions are met	B

   Post-procedure1

3. None

Result: 

B 

See step  25

Result: 

A 

See step  21

1. Inspect other related components.

   HINT: 

   If the malfunctioning part could not be determined by performing the preceding inspections, one of the following malfunctions is suspected.

   • Deposits in the intake manifold or on an intake valve
   • Delay in fuel supply due to adherence of the fuel to the deposits

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  25

1. Inspect the following fuel pump assembly (for low pressure side) related parts:
   • Fuel suction plate sub-assembly
   • Fuel main valve assembly
   • Fuel lines and connecting parts
   • Fuel filter

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  25

1. Check for air leaks or blockage in the intake system components. If a connection problem or foreign matter is found, repair the connection or remove the foreign matter.

   HINT: 

   • If there is foreign matter in the intake system components, remove it before proceeding to the next step.
   • If there is no foreign matter in the intake system components, check for foreign matter in the mass air flow meter sub-assembly. If there is foreign matter in the mass air flow meter sub-assembly, remove it.

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  25

1. Inspect the fuel pump control system.

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  25

1. Repair or replace the malfunctioning part.
2. Perform "Inspection After Repair" after repairing or replacing the malfunctioning part.

   Refer to INITIALIZATION [12/2021 - ]

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  26

1. Check that the engine has returned to normal.

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  27

1. Clear the DTCs.

   Powertrain > Engine > Clear DTCs 

   Result

   Proceed to
   NEXT

Result: 

NEXT 

END