DTC P1604: Startability Malfunction: Description

This DTC is stored when the engine does not start even though the STA signal is input or when the engine takes a long time to start, and when the engine speed is low or the engine stalls just after the engine starts.

Using the Techstream, the conditions present when the DTC was stored can be confirmed by referring to the freeze frame data. Freeze frame data records engine conditions when a malfunction occurs. This information can be useful when troubleshooting.

It is necessary to check if the vehicle ran out of fuel before performing troubleshooting, as this DTC is also stored when there is engine starting trouble due to running out of fuel.

DTC No.	DTC Detection Condition	Trouble Area
P1604	Either condition is met: The engine speed is below 500 rpm with the STA signal on for a certain amount of time (refer to the illustration below) (1 trip detection logic). After the engine starts (engine speed is 500 rpm or more), the engine speed drops to 200 rpm or less within approximately 2 seconds (1 trip detection logic).	Engine assembly (excess friction, compression loss) Starter Crankshaft position sensor Camshaft position sensor (for intake or exhaust camshaft) Engine coolant temperature sensor Fuel pump Fuel pump control circuit Fuel lines (fuel filter, pipes and hoses) Fuel injector Throttle body Pressure regulator Battery Drive plate and ring gear sub-assembly1 Flywheel sub-assembly2 Spark plug Ignition coil circuit Intake system Camshaft timing oil control valve (for intake or exhaust camshaft) Mass air flow meter Air fuel ratio sensor Valve timing Fuel Purge VSV Intake valve Exhaust valve Immobiliser system (w/ immobiliser system) ECM

*1: for Automatic Transaxle
*2: for Manual Transaxle

Fig 1: Identifying STA Signal

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Reference waveforms showing a normal cold engine start

Fig 2: Identifying Waveforms Showing A Normal Cold Engine Start
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Reference waveforms showing a normal warm engine start

Fig 3: Warm Engine Waveform
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Reference values when there is an air leak in the intake system during starting difficulty

FREEZE FRAME DATA P1604 STARTABILITY MALFUNCTION

Freeze Frame Data P1604: Startability Malfunction
Parameter	-3	-2	-1	0	1	Unit
Engine Speed	1497	794	334	249	249	rpm
Calculate Load	34.5	28.2	32.1	87.8	87.4	%
Vehicle Load	8.6	21.9	15.6	7.4	5.8	%
MAF	1.70	2.31	0.70	0.25	0.20	gm/sec
Atmosphere Pressure	-0	-0	-0	-0	-0	psi(gauge)
Coolant Temp	167	167	167	167	167	F
Intake Air	93	93	93	93	93	F
Ambient Temperature	66	66	66	66	66	F
Battery Voltage	13.2	13.0	12.3	12.3	12.3	V
Throttle Sensor Volt %	16.0	17.6	17.2	15.6	15.6	%
Throttle Sensor #2 Volt %	48.2	50.1	49.4	47.8	47.8	%
Throttle Sensor Position	0.0	0.0	0.0	0.0	0.0	%
Throttle Motor DUTY	16.0	17.6	17.6	15.6	15.6	%
Injector (Port)	3200	2560	2560	2560	2560	μs
Injection Volume (Cylinder 1)	0.152	0.152	0.152	0.152	0.152	ml
Fuel Pump/Speed Status	ON	ON	ON	ON	ON
EVAP (Purge) VSV	0.0	0.0	0.0	0.0	0.0	%
Evap Purge Flow	0.0	0.0	0.0	0.0	0.0	%
Purge Density Learn Value	0.000	0.000	0.000	0.000	0.000
EVAP Purge VSV	OFF	OFF	OFF	OFF	OFF
Target Air-Fuel Ratio	0.830	0.841	0.871	0.799	0.799
AF Lambda B1 S1	1.014	1.016	1.021	1.022	1.027
AFS Voltage B1S1	3.37	3.38	3.40	3.41	3.42	V
O2S B1S2	0.82	0.31	0.07	0.05	0.03	V
Short FT #1	0.0	0.0	0.0	0.0	0.0	%
Long FT #1	0.0	-4.0	-4.7	-4.7	-4.7	%
Total FT #1	-0.043	-0.043	-0.043	-0.043	-0.043
Fuel System Status #1	OL	OL	OL	OL	OL
IGN Advance	-4.0	2.0	4.0	0.0	0.0	deg
Knock Feedback Value	-3.0	-3.0	-3.0	-3.0	-3.0	CA
Knock Correct Learn Value	14.0	14.0	14.0	14.0	14.0	CA
VVT Control Status #1	OFF	OFF	OFF	OFF	OFF
Starter Signal	OFF	OFF	OFF	OFF	OFF