P0418

DTC Code	DTC Name
P0418	Secondary Air Injection System Control "A" Circuit

DESCRIPTION

Refer to DTC P0412.

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DTC No.	Detection Item	DTC Detection Condition	Trouble Area	MIL	Memory
P0418	Secondary Air Injection System Control "A" Circuit	Condition 1: After cold engine starts, all of following conditions met (2 trip detection logic): Secondary air injection system not operating (air pump OFF, air switching valve OFF) Diagnostic signal from air injection control driver 20% Battery voltage 8 V or more Condition 2: After cold engine starts, all of following conditions met (2 trip detection logic): Secondary air injection system operating (air pump ON, air switching valve ON) Diagnostic signal from air injection control driver 20% Battery voltage 8 V or more	Condition 1: Open in air pump drive circuit Short between air pump drive circuit and +B circuit Air pump assembly Air injection control driver ECM Condition 2: Short between air pump drive circuit and body ground Air pump assembly Air injection control driver ECM	Comes on	DTC stored

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Memory

P0418

Secondary Air Injection System Control "A" Circuit

Condition 1:

After cold engine starts, all of following conditions met (2 trip detection logic):

Secondary air injection system not operating (air pump OFF, air switching valve OFF)
Diagnostic signal from air injection control driver 20%
Battery voltage 8 V or more

Condition 2:

After cold engine starts, all of following conditions met (2 trip detection logic):

Secondary air injection system operating (air pump ON, air switching valve ON)
Diagnostic signal from air injection control driver 20%
Battery voltage 8 V or more

Condition 1:

Open in air pump drive circuit
Short between air pump drive circuit and +B circuit
Air pump assembly
Air injection control driver
ECM

Condition 2:

Short between air pump drive circuit and body ground
Air pump assembly
Air injection control driver
ECM

Comes on

DTC stored

MONITOR DESCRIPTION

The Air Injection Control Driver (AID) detects open and short circuits according to the voltages of the air pump terminal and the Air Switching Valve (ASV) terminal, and transmits diagnostic information as a signal to the ECM.

For a short time after cold engine starts, the ECM transmits command signals to the AID to drive the air pump and ASV.

The AID transmits an air pump malfunction signal to the ECM if either of the following conditions is met:

The voltage at the AID terminal relating to the air pump is low despite the AID receiving command signals from the ECM to drive the air pump.
The voltage at the AID terminal relating to the air pump is high despite the AID receiving no command signals from the ECM to drive the air pump.

The ECM stores the DTC based on diagnostic signals from the AID.

MONITOR STRATEGY

Required Sensors/Components (Main)	Air injection control driver
Required Sensors/Components (Related)	Air pump assembly
Frequency of Operation	Once per drive cycle

CONFIRMATION DRIVING PATTERN

Note

This Secondary Air Injection Check only allows technicians to operate the secondary air injection system for a maximum of 5 seconds.

Furthermore, the check can only be performed up to 4 times per trip. If the test is repeated, intervals of at least 30 seconds are required between checks.

While secondary air injection system operation using the GTS is prohibited, the GTS display indicates the prohibition (WAIT or ERROR).

If ERROR is displayed on the GTS during the test, stop the engine for 10 minutes, and then try again.
Performing the Secondary Air Injection Check repeatedly may cause damage to the secondary air injection system. If necessary, leave an interval of several minutes between System Check operations to prevent the system from overheating.
When performing the Secondary Air Injection Check operation after the battery cable has been reconnected, wait for 7 minutes with the ignition switch turned to ON or the engine running.
Turn the ignition switch off when the Secondary Air Injection Check operation finishes.

Start the engine and warm it up.
Turn the ignition switch off.
Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Clear DTCs (even if no DTCs are stored, perform the clear DTC operation).
Turn the ignition switch off and wait for at least 30 seconds.
Turn the ignition switch to ON and turn the GTS on.
Enter the following menus: Powertrain / Engine and ECT / Utility / Secondary Air Injection Check / Automatic Mode.
Start the engine after the GTS initialization is finished.
Perform the System Check operation by pressing Next.
Perform the following to confirm the secondary air injection system pending DTCs: Press Exit button.
Check for pending DTCs.

OK

No pending DTC is output.
After the "Secondary Air Injection Check" is completed, check for All Readiness by entering the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
Input the DTC: P0418.

OK
No pending DTC is output.

Check the DTC judgment result.

GTS Tester Display	Description
NORMAL	DTC judgment completed System normal
ABNORMAL	DTC judgment completed System abnormal
INCOMPLETE	DTC judgment not completed Perform driving pattern after confirming DTC enabling conditions
N/A	Unable to perform DTC judgment Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit

Tech Tips

If the judgment result shows NORMAL, the system is normal.
If the judgment result shows ABNORMAL, the system has a malfunction.

Turn the ignition switch off.

WIRING DIAGRAM

Refer to DTC P0412.

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CAUTION / NOTICE / HINT

CAUTION:

Inspect the fuses for circuits related to this system before performing the following inspection procedure.

Note

After turning the ignition switch off, waiting time may be required before disconnecting the cable from the negative (-) battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) battery terminal notices before proceeding with work.

Tech Tips

Read freeze frame data using the GTS. Freeze frame data records 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.

PROCEDURE

CHECK HARNESS AND CONNECTOR (AIR PUMP - AIR INJECTION DRIVER - BODY GROUND)

Disconnect the air pump connector.
Disconnect the air injection driver.
Disconnect the cable from the negative (-) battery terminal.
Disconnect the cable from the positive (+) battery terminal.

Measure the resistance according to the value(s) in the table below.

Standard Resistance

Tester Connection	Condition	Specified Condition
A14-2 - A33-2 (VP)	Always	Below 1 Ω
A14-4 - Body ground	Always	Below 1 Ω
A33-1 (BATT) - Positive (+) battery terminal	Always	Below 1 Ω
A14-2 or A33-2 (VP) - Body ground	Always	10 kΩ or higher
A33-1 (BATT) or Positive (+) batteryterminal - Body ground	Always	10 kΩ or higher

Result

Proceed to
OK
NG

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

INSPECT AIR PUMP ASSEMBLY

Inspect the air pump assembly.

Click here

Result

Proceed to
OK
NG

OK

REPLACE AIR INJECTION CONTROL DRIVER Click here

NG

REPLACE AIR PUMP ASSEMBLY

Replace the air pump assembly.

Click here

Result

Proceed to
NEXT

CHECK WHETHER DTC OUTPUT RECURS

Start the engine and warm it up.
Turn the ignition switch off.
Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Clear DTCs (even if no DTCs are stored, perform the clear DTC operation).

Powertrain > Engine > Clear DTCs
Turn the ignition switch off and wait for at least 30 seconds.
Turn the ignition switch to ON and turn the GTS on.
Enter the following menus: Powertrain / Engine and ECT / Utility / Secondary Air Injection Check / Automatic Mode.

Powertrain > Engine > Utility

Tester Display

Secondary Air Injection Check
Start the engine after the GTS initialization is finished.
Perform the System Check operation by pressing Next.
After operating the secondary air injection system, perform the following to confirm the secondary air injection system pending codes: Press the Exit button.
Read pending DTCs.

OK

No pending DTC is output.

Tester Display
Secondary Air Injection Check

OK
No pending DTC is output.

Turn the ignition switch off.

Note

When performing the Secondary Air Injection Check operation after the battery cable has been reconnected, wait for 7 minutes with the ignition switch turned to ON or the engine running.
Turn the ignition switch off when the Secondary Air Injection Check operation finishes.

Result

Proceed to
OK
NG

OK

END

NG

REPLACE AIR INJECTION CONTROL DRIVER Click here

СИСТЕМА SFI, Diagnostic DTC:P0418