Caution / Notice / Hint

HINT: 

• DTC P1603 / P1605
  • In contrast to normal malfunction diagnosis for components, circuits and systems, DTCs P1603 and P1605 are used to determine the malfunctioning area from the problem symptoms and freeze frame data when the user mentions problems such as engine stall.

    As these DTCs can be stored as a result of certain user actions, even if these DTCs are output, if the customer makes no mention of problems, clear these DTCs without performing any troubleshooting and return the vehicle to the customer.

  • As DTCs may be stored when an Active Test or learning is performed, make sure to clear the DTCs before returning the vehicle to the customer.
  • If any other DTCs are output, perform troubleshooting for those DTCs first.
• CUSTOMER PROBLEM ANALYSIS

  Use any information from the customer problem analysis about the condition of the vehicle at the time when the problem occurred (how the engine stopped, conditions when the engine was restarted, etc.) as a reference.

  Symptom	Suspected Area
  Engine vibration occurs and engine stops	Abnormal mass air flow meter sub-assembly output due to existence of foreign matter Abnormal air fuel ratio due to malfunction of air fuel ratio sensor or heated oxygen sensor, air leaks in intake system or insufficient fuel supply
  Engine stops with no engine vibration	Ignition system, injection stoppage, high load from external parts
  Engine can be started with accelerator pedal depressed	Insufficient air volume
  Engine stalls or is difficult to start immediately after engine stalled, regardless of whether engine is cold or warm	Deposits in intake system or combustion chamber caught temporarily on intake or exhaust valve

• FREEZE FRAME DATA
  • Read freeze frame data using the Techstream. Freeze frame data records engine conditions when a malfunction occurs. This information can be useful when troubleshooting.
  • When confirming the freeze frame data, be sure to check all 5 sets of freeze frame data.

    Refer to FREEZE FRAME DATA [08/2016 - ]

  • When DTC P1603 (Engine Stall History) is stored, DTC P1605 (Rough Idling) is also stored. When confirming freeze frame data, check DTC P1605. The ECM stores DTC P1605 first. Therefore, 5 sets of freeze frame data can be confirmed through DTC P1605, enabling the technician to obtain more information.
  • When confirming freeze frame data, if there are multiple items related to the cause of the malfunction, perform troubleshooting for all related items.
  • Try to operate the vehicle under the conditions recorded in the freeze frame data which were present when the malfunction occurred. Confirm the data at this time and the data when the engine is idling (engine warmed up, no load, and shift lever in D or N) and compare this data with the freeze frame data.
• PRECAUTIONS
  • Inspections take into account the fact that the malfunction may not have recurred and place emphasis on checking the vehicle conditions present at the time when the malfunction occurred.
  • When performing inspections, jiggle the relevant wire harnesses and connectors in an attempt to reproduce malfunctions that do not always occur.

Inspection flow

Using freeze frame data, narrow down the parts to be inspected according to the vehicle conditions at the time when the malfunction occurred.

P1603: 

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1: 

• If the engine stalled when the intake air volume was low (during idling or deceleration), there may be a decrease in torque due to an incorrect air fuel ratio, etc.
• If the engine stalled when the intake air volume was high (during driving or acceleration), there may be a major malfunction such as continuous misfire due to ignition stoppage, fuel injection stoppage, etc. and the torque drops to zero.

2: 

• If the engine speed decreased slowly, there may have been a decrease in torque due to an air fuel ratio that was incorrect (by approximately 20 to 30%), etc.
• If the engine speed decreased rapidly, there may have been a malfunction such as when the engine misfires almost continuously due to ignition stoppage, fuel injection stoppage, etc., or when the external load increases due to an external part malfunctioning.

3: 

• If the air fuel ratio is abnormal, there may have been an intake air leak, sensor malfunction, or fuel supply problem.
• If the vehicle was normal, the air volume may have been insufficient or the ignition timing may have been incorrect.

P1603 inspection flow: Narrow down the parts to be inspected according to the vehicle conditions at the time when the malfunction occurred (freeze frame data).

Vehicle State	Engine Speed	Suspected Area		Primary Parts to Inspect	Procedure
Idling or decelerating	Slowly decreases and engine stalls	Ignition system abnormal	Igniter abnormal	Power supply circuit Ignition coil assembly Spark plug	10, 38, 53
		Air fuel ratio abnormal	Air suction	Intake system connections Purge VSV system Brake booster assembly	5 to 9
			Sensor malfunction (value from sensor too lean)	Mass air flow meter sub-assembly Engine coolant temperature sensor Air fuel ratio sensor system Thermostat	11 to 23
			Sensor malfunction (value from sensor too rich)		39 to 51
			Fuel supply problem	Fuel pump control circuit Purge VSV system Fuel line ECM	24 to 37
		Intake air volume insufficient	Problem with air passage	Intake system connections Mass air flow meter sub-assembly Brake booster assembly PCV valve and hose Purge VSV system	54 to 56
			Excessive valve overlap	Camshaft timing oil control valve assembly	57 to 60
		Ignition timing incorrect	Does not operate as expected	Knock control sensor Engine coolant temperature sensor Mass air flow meter sub-assembly	61 to 65
	Rapidly decreases and engine stalls	Ignition and injection stops (electrical system malfunction)	Power temporarily cut	Power supply circuit (fuel injector assembly, ignition coil assembly)	66, 67
		External part malfunctioning	Increase in load	Air conditioning system Electrical load signal system Power steering system CVT system Park/Neutral position switch assembly	68 to 71
Accelerating	-	Crankshaft position sensor or camshaft position sensor (No. 1 crank position sensor) malfunction	Power temporarily cut	Check DTCs	1
		Mass air flow meter	Foreign matter adhesion	Mass air flow meter sub-assembly	72 to 75
		Ignition and injection stops (electrical system malfunction)	Power temporarily cut	Power supply circuit (fuel injector assembly, ignition coil assembly)	76, 77
		Fuel supply problem	Fuel leak, clog	Fuel pump control circuit Fuel line	78 to 82

P1605: 

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1: 

• If the engine speed decreased slowly, there may have been a decrease in torque due to an air fuel ratio that was incorrect (by approximately 20 to 30%), etc.
• If the engine speed decreased rapidly, there may have been a malfunction such as when the engine misfires almost continuously due to ignition stoppage, fuel injection stoppage, etc., or when the external load increases due to an external part malfunctioning.

2: 

• If the air fuel ratio is abnormal, there may have been an intake air leak, sensor malfunction, or fuel supply problem.
• If the vehicle was normal, the air volume may have been insufficient or the ignition timing may have been incorrect.

P1605 inspection flow: Narrow down the parts to be inspected according to the vehicle conditions at the time when the malfunction occurred (freeze frame data).

Engine Speed	Suspected Area		Primary Parts to Inspect	Procedure
Slowly decreases	Ignition system abnormal	Igniter abnormal	Power supply circuit Ignition coil assembly Spark plug	10, 38, 53
	Air fuel ratio abnormal	Air suction	Intake system connections Purge VSV system Brake booster assembly	5 to 9
		Sensor malfunction (value from sensor too lean)	Mass air flow meter sub-assembly Engine coolant temperature sensor Air fuel ratio sensor system Thermostat	11 to 23
		Sensor malfunction (value from sensor too rich)		39 to 51
		Fuel supply problem	Fuel pump control circuit Purge VSV system Fuel line ECM	24 to 37
	Intake air volume insufficient	Problem with air passage	Intake system connections Mass air flow meter sub-assembly Brake booster assembly PCV valve and hose Purge VSV system	54 to 56
		Excessive valve overlap	Camshaft timing oil control valve assembly	57 to 60
	Ignition timing incorrect	Does not operate as expected	Knock control sensor Engine coolant temperature sensor Mass air flow meter sub-assembly	61 to 65
Rapidly decreases	Ignition and injection stops (electrical system malfunction)	Power temporarily cut	Power supply circuit (fuel injector assembly, ignition coil assembly)	66, 67
	External part malfunctioning	Increase in load	Air conditioning system Electrical load signal system Power steering system CVT system* Park/Neutral position switch assembly*	68 to 71

• *: for CVT Models