Toyota FJ Cruiser (GSJ 10, 15 series). Instruction - part 76

1GR-FE ENGINE CONTROL SYSTEM  –  SFI SYSTEM

ES–259

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(a) Check the throttle valve condition.

OK:

Throttle valve is not contaminated with foreign 
objects and moves smoothly.

NG

OK

4

CHECK THROTTLE VALVE

REPAIR OR REPLACE THROTTLE WITH 
MOTOR BODY ASSEMBLY

REPLACE ECM (See page 

ES-446

)

ES–260

1GR-FE ENGINE CONTROL SYSTEM  –  SFI SYSTEM

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DESCRIPTION

The Electronic Throttle Control System (ETCS) controls the engine idling speed. The ETCS operates the 
throttle actuator to open and close the throttle valve, and adjusts the intake air amount to achieve the 
target idling speed.
In addition, the ECM retards the ignition timing and the ETCS increases the intake air amount to quickly 
increase the catalyst temperature at cold start to reduce emissions.

MONITOR DESCRIPTION

DTC

P050A

Cold Start Idle Air Control System Performance

DTC

P050B

Cold Start Ignition Timing Performance

DTC No.

DTC Detection Conditions

Trouble Areas

P050A

Accumulated intake air amount during 10 seconds of idling 
after cold start, less than threshold (2 trip detection logic)

•

Throttle body assembly

•

Mass air flow meter

•

Air induction system

•

PCV hose connections

•

VVT system

•

Air cleaner filter element

•

ECM

P050B

Ignition timing retard value insufficient for 5 seconds or more 
during 10 seconds of P050A monitoring duration at cold start 
(2 trip detection logic)

•

Throttle body assembly

•

Mass air flow meter

•

Air induction system

•

PCV hose connections

•

VVT system

•

Air cleaner filter element

•

ECM

Accumulated Intake Air Value

Ignition Timing

Advanced

Retarded

Engine Start

Engine Start

Threshold

Threshold

Pass Detected

P050A Detected

0

3

10

(Second)

3

10

(Second)

Time

5 or more

P050B Detected

Pass Detected

(g)

Time

A112588E01

1GR-FE ENGINE CONTROL SYSTEM  –  SFI SYSTEM

ES–261

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The ECM monitors the intake air amount during idling and the ignition timing.
When the Engine Coolant Temperature (ECT) is between -10

°C and 50 °C (14°F and 122°F), the ECM 

calculates the idling intake air amount for 10 seconds, beginning 3 seconds after the engine starts.
When the accumulated value is below the threshold, the ECM interprets this as a malfunction in the Idle 
Speed Control (ISC) system at cold start.
The ECM also monitors the ignition timing at cold start, and judges it to be incorrect when it is advanced to 
the same value for a warm engine for 5 seconds or more of the 10 second monitoring period.
Example:
P050A is detected when all conditions below are met (2 trip detection logic).
1. The ECT is between -10

°C and 50 °C (14°F and 122°F) when the engine starts.

2. The engine idles for 13 seconds after engine start.
3. The accumulated intake air amount is below the threshold.
The ECM sets the DTC and illuminates the MIL 13 seconds after the engine is next started.
NOTICE:
When the negative battery terminal is disconnected during inspection or repairs, the ISC learning 
values are cleared. The ISC learning must be performed by warming up the engine and idling for 5 
minutes with the ECT at 75

°C (167°F) or more because DTCs cannot be detected with the ISC 

learning values cleared.

MONITOR STRATEGY

TYPICAL ENABLING CONDITIONS

P050A:

P050B:

Related DTCs

P050A: Idle speed control problem at cold
P050B: Idle ignition timing problem at cold

Required Sensors/Components (Main)

Mass air flow meter

Required Sensors/Components (Related)

Engine Coolant Temperature (ECT) sensor, Throttle position sensor, 
Vehicle speed sensor

Frequency of Operation

Once per driving cycle

Duration

10 seconds

MIL Operation

2 driving cycles

Sequence of Operation

None

Battery voltage

8 V or more

Time after engine start

3 seconds or more

Starter

OFF

ECT at engine start

-10

°C (14°F) or more

ECT

-10

°C to 50°C (14°F to 122°F)

Engine idling time

3 seconds or more

Fuel-cut

OFF

Vehicle speed

Less than 1.875 mph (3 km/h)

Time after shift position changed (A/T)

1 second or more

Atmospheric pressure

76 kPa (570 mmHg) or more

Battery voltage

8 V or more

Time after engine start

3 seconds or more

Starter

OFF

ECT at engine start

-10

°C (14°F) or more

ECT

-10

°C to 50°C (14°F to 122°F)

Engine idling time

3 seconds or more

Fuel-cut

OFF

Vehicle speed

Less than 1.875 mph (3 km/h)

ES–262

1GR-FE ENGINE CONTROL SYSTEM  –  SFI SYSTEM

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TYPICAL MALFUNCTION THRESHOLDS

P050A:

P050B:

INSPECTION PROCEDURE

HINT:
Read freeze frame data using an intelligent tester. Freeze frame data record the engine condition when 
malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was 
moving or stationary, if the engine was warmed up or not, if the air-fuel ratio was lean or rich, and other 
data, from the time the malfunction occurred.

(a) Connect an intelligent tester to the DLC3.
(b) Turn the ignition switch ON.
(c) Turn the tester ON.
(d) Select the following the menu items: DIAGNOSIS / 

ENHANCED OBD II / DTC INFO / CURRENT CODES.

(e) Read the DTCs.

Result

HINT:
If any DTCs other than P050A and P050B are output, 
troubleshoot those DTCs first.

B

A

HINT:
Calculate the total fuel trim values to check the characteristic 
deviation of the mass air flow meter.
(a) Connect the intelligent tester to the DLC3.
(b) Turn the ignition switch ON.
(c) Turn the tester ON.
(d) Select the following menu items: DIAGNOSIS / 

ENHANCED OBD II / DATA LIST / PRIMARY / SHORT 
FT #1 and LONG FT #1, or SHORT FT #2 and LONG FT 
#2.

(e) Read the values displayed on the tester.
(f)

Add together the SHORT FT #1 and LONG FT #1, or 
SHORT FT #2 and LONG FT #2 values to obtain the 
total FUEL TRIM.

Accumulated air flow amount (M/T)

Varies with ECT (Example: Less than 42.5 g)

Accumulated air flow amount (A/T)

Varies with ECT (Example: Less than 47.5 g)

Accumulated time when ignition timing retard value insufficient

5 seconds or more

1

CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P050A AND/OR P050B)

Display (DTC Output)

Proceed To

P050A and/or P050B

A

P050A and/or P050B and other DTCs

B

GO TO DTC CHART (See page 

ES-57

)

2

READ VALUE USING INTELLIGENT TESTER (FUEL TRIM)