Test Procedure

NOTE: Proceed to DTC testing steps listed in FAULT CODE SETTING CONDITION table of fault code setting condition.

FAULT CODE SETTING CONDITION

Fault Code	KOEO	KOER	Continuous Memory
P0411		HM17	HM17
P0412	HM1	HM1	HM1
P2257	HM37	HM37	HM37
P2258	HM49	HM49	HM49

HM1 KOEO AND KOER DTC P0412: ISOLATE THE COMMAND SIGNAL CIRCUIT TO 1 COMPONENT AND RERUN THE SELF-TEST

NOTE: Only start at this step if you followed the SYMPTOM CHARTS - CNG, FLEX-FUEL & GASOLINE PCM Quick Test direction and a KOEO or KOER DTC is present.

Key OFF.
Scan tool connector connected.
AIR Solenoid connector disconnected.
Key ON Engine OFF.
CLEAR the DTCs.
Run KOEO Self-Test.

Is DTC P0412 present?

Yes	No
GO to HM2.	KEY OFF. INSTALL a new AIR solenoid.

HM2 CHECK THE RESISTANCE OF AIR SOLENOID

Measure the resistance between:

( + )AIR Solenoid Connector, Component Side	( - )AIR Solenoid Connector, Component Side
SAIR - Pin 1	VPWR - Pin 2

Is the resistance between 50 ohms - 95 ohms?

Yes	No
GO to HM3.	KEY OFF. INSTALL a new AIR solenoid.

HM3 CHECK THE VPWR VOLTAGE TO THE AIR SOLENOID

Measure the voltage between:

( + )AIR Solenoid Connector, Harness Side	( - )
VPWR - Pin 2	Ground

Is the voltage greater than 10.5 V?

Yes	No
GO to HM4.	KEY OFF. REPAIR open circuit.

HM4 ISOLATE THE COMMAND SIGNAL CIRCUIT TO 1 COMPONENT AND RERUN THE SELF-TEST

Key OFF.
AIR Solenoid connector connected.
AIR Relay connector disconnected.
Key ON Engine OFF.
CLEAR the DTCs.
Run KOEO Self-Test.

Is DTC P0412 present?

Yes	No
GO to HM5.	KEY OFF. INSTALL a new AIR relay.

HM5 CHECK THE RESISTANCE OF AIR RELAY

Measure the resistance between:

( + )AIR Relay Connector, Component Side	( - )AIR Relay Connector, Component Side
SAIR - Pin 85	VPWR - Pin 86

Is the resistance between 40 ohms - 80 ohms?

Yes	No
GO to HM6.	KEY OFF. INSTALL a new AIR relay.

HM6 CHECK THE VPWR VOLTAGE TO THE AIR RELAY

Measure the voltage between:

( + )AIR Relay Connector, Harness Side	( - )
VPWR - Pin 86	Ground

Is the voltage greater than 10.5 V?

Yes	No
GO to HM7.	KEY OFF. REPAIR open circuit.

HM7 CHECK THE SAIR CIRCUIT(S) FOR AN OPEN IN THE HARNESS

Key OFF.
AIR Solenoid connector disconnected.
PCM connector disconnected.

Measure the resistance between:

( + )PCM Connector, Harness Side	( - )AIR Solenoid Connector, Harness Side
SAIR - Pin B17	SAIR - Pin 1

Measure the resistance between:

( + )PCM Connector, Harness Side	( - )AIR Relay Connector, Harness Side
SAIR - Pin B17	SAIR - Pin 85

Is the resistance less than 5 ohms?

Yes	No
GO to HM8.	REPAIR open circuit.

HM8 CHECK THE SAIR FOR SHORTS TO POWER(S) AND GROUND(S) IN THE HARNESS - DIRECT AND INDIRECT

Measure the resistance between:

( + )PCM Connector, Harness Side	( - )PCM Connector, Harness Side
SAIR - Pin B17	VPWR - Pin B35
SAIR - Pin B17	PWRGND - Pin B47
SAIR - Pin B17	CASE GND - Pin B10
SAIR - Pin B17	SIGRTN - Pin B41
SAIR - Pin B17	VREF - Pin B40

Measure the resistance between:

( + )PCM Connector, Harness Side	( - )
SAIR - Pin B17	Ground

Is the resistance greater than 10K ohms?

Yes	No
INSTALL a new PCM. REFER to FLASH ELECTRICALLY ERASEABLE PROGRAMMABLE READ ONLY MEMORY - FLASH EEPROM .	REPAIR short circuit.

HM9 CONTINUOUS MEMORY DTC P0412: WIGGLE TEST ON THE AIR HARNESS SAIR CIRCUIT LOOKING FOR AN OPEN CIRCUIT OR SHORT TO GROUND - PCM OUTPUT OFF

NOTE: Only start at this step if you followed the SYMPTOM CHARTS - CNG, FLEX-FUEL & GASOLINE PCM Quick Test direction and no KOEO or KOER DTC is present.

NOTE: Open circuit and short-to -ground conditions are detected when the PCM output driver is OFF. The AIRF PID instantly shows a SAIR PCM output circuit open or short to ground fault - PCM output OFF.

Key ON Engine OFF.
Scan tool connector connected.
Access the PCM -AIR, PCM-AIRM and PCM-AIRF PIDs.
Observe the PCM output driver fault PID AIRF. Wiggle the SAIR harness and connectors, and lightly tap the components while observing the AIRF PID.

Was a fault found?

Yes	No
KEY OFF. REPAIR/REPLACE as necessary	GO to HM10.

HM10 WIGGLE TEST ON THE AIR HARNESS SAIR CIRCUIT LOOKING FOR A SHORT TO POWER OR LOW RESISTANCE LOAD TO POWER - PCM OUTPUT ON

CAUTION: Running the AIR pump with OTM longer than 2 minutes may overheat and damage the AIR pump. Refer to DIAGNOSTIC METHODS - CNG, FLEX-FUEL & GASOLINE , OTM).

NOTE: The SAIR PCM output driver detects a short-to -power condition, when the driver is on. The AIRF PID instantly shows a SAIR PCM output circuit short to power or low resistance short to power fault - PCM output ON.

Scan Tool Connected
Enter Output Test Mode. Refer to OUTPUT TEST MODE .
Command outputs ON
Observe the PCM output driver fault PID AIRF. While commanding outputs on with OTM, wiggle the SAIR line harness and connectors, and lightly tap components while observing the AIRF PID.
Command outputs OFF
Exit Output Test Mode

Was a fault found?

Yes	No
KEY OFF. REPAIR/REPLACE as necessary	KEY OFF. GO to HM11.

HM11 CHECK THE RESISTANCE OF AIR SOLENOID

AIR Solenoid connector disconnected.

Measure the resistance between:

( + )AIR Solenoid Connector, Component Side	( - )AIR Solenoid Connector, Component Side
SAIR - Pin 1	VPWR - Pin 2

Is the resistance between 50 ohms-95 ohms?

Yes	No
GO to HM12.	INSTALL a new AIR solenoid.

HM12 CHECK THE VPWR VOLTAGE TO THE AIR SOLENOID

Key ON Engine OFF.

Measure the voltage between:

( + )AIR Solenoid Connector, Harness Side	( - )
VPWR - Pin 2	Ground

Is the voltage greater than 10.5 V?

Yes	No
KEY OFF. GO to HM13.	KEY OFF. REPAIR open circuit.

HM13 CHECK THE RESISTANCE OF AIR RELAY

AIR Relay connector disconnected.

Measure the resistance between:

( + )AIR Relay Connector, Component Side	( - )AIR Relay Connector, Component Side
SAIR - Pin 85	VPWR - Pin 86

Is the resistance between 40 ohms - 80 ohms?

Yes	No
GO to HM14.	INSTALL a new AIR relay.

HM14 CHECK THE VPWR VOLTAGE TO THE AIR RELAY

Key ON Engine OFF.

Measure the voltage between:

( + )AIR Relay Connector, Harness Side	( - )
VPWR - Pin 86	Ground

Is the voltage greater than 10.5 V?

Yes	No
GO to HM15.	KEY OFF. REPAIR open circuit.

HM15 CHECK THE SAIR CIRCUIT(S) FOR AN OPEN IN THE HARNESS

Key OFF.
PCM connector disconnected.

Measure the resistance between:

( + )PCM Connector, Harness Side	( - )AIR Solenoid Connector, Harness Side
SAIR - Pin B17	SAIR - Pin 1

Measure the resistance between:

( + )PCM Connector, Harness Side	( - )AIR Relay Connector, Harness Side
SAIR - Pin B17	SAIR - Pin 85

Is the resistance less than 5 ohms?

Yes	No
GO to HM16.	REPAIR open circuit.

HM16 CHECK THE SAIR FOR SHORTS TO POWER(S) AND GROUND(S) IN THE HARNESS - DIRECT AND INDIRECT

Measure the resistance between:

( + )PCM Connector, Harness Side	( - )PCM Connector, Harness Side
SAIR - Pin B17	VPWR - Pin B35
SAIR - Pin B17	PWRGND - Pin B47
SAIR - Pin B17	CASE GND - Pin B10
SAIR - Pin B17	SIGRTN - Pin B41
SAIR - Pin B17	VREF - Pin B40

Measure the resistance between:

( + )PCM Connector, Harness Side	( - )
SAIR - Pin B17	Ground

Is the resistance greater than 10K ohms?

Yes	No
Unable to duplicate or identify the fault at this time. GO to PINPOINT TEST Z step 1 .	REPAIR short circuit.

HM17 DTC P0411: VISUALLY INSPECT THE AIR SYSTEM COMPONENTS AND HOSES

Visually inspect the AIR system components and hoses for damage, obstruction, binding, including exhaust damage, cracking, a blocked water shield on the AIR pump inlet hose, water, or ice.

Are the AIR system components and hoses OK?

Yes	No
GO to HM18.	KEY OFF. REPAIR/REPLACE as necessary CLEAR the DTCs and REPEAT Self-Test.

HM18 CHECK THE AIR PUMP/MOTOR OPERATION

CAUTION: Running the AIR pump with OTM longer than 2 minutes may overheat and damage the AIR pump. Refer to DIAGNOSTIC METHODS - CNG, FLEX-FUEL & GASOLINE , OTM).

Key ON Engine OFF.
Scan Tool Connected
Enter Output Test Mode. Refer to OUTPUT TEST MODE .
Listen for the AIR pump operation while toggling to OTM states from ON to OFF.
Command outputs ON
Command outputs OFF
Exit Output Test Mode

Does AIR pump operation correspond with the OTM ON and OFF commands?

Yes	No
GO to HM19.	GO to HM33.

HM19 MEASURE THE VACUUM AT THE AIR DIVERTER VALVE

Connect a vacuum gauge to the control vacuum hose at the AIR diverter valve(s).
Apply 54 kPa (16 in-Hg) of vacuum at the manifold side of the AIR bypass solenoid vacuum supply hose(s).
Scan Tool Connected
Enter Output Test Mode. Refer to OUTPUT TEST MODE .
Command outputs ON
Observe the vacuum gauge reading at the AIR diverter valve(s).
Command outputs OFF

Is applied vacuum present at the AIR diverter valve(s)?

Yes	No
GO to HM22.	Exit Output Test Mode GO to HM20.

HM20 MEASURE THE VACUUM AT THE AIR SOLENOID VALVE

Connect a vacuum gauge to the control vacuum outlet at the AIR solenoid valve(s).
Apply 54 kPa (16 in-Hg) of vacuum at the manifold side of the AIR bypass solenoid vacuum supply hose(s).
Scan Tool Connected
Enter Output Test Mode. Refer to OUTPUT TEST MODE .
Command outputs ON
Observe the vacuum gauge reading at the AIR solenoid valve.
Command outputs OFF
Exit Output Test Mode

Is applied vacuum present at the AIR diverter valve(s)?

Yes	No
KEY OFF. REPAIR/REPLACE as necessary the restricted vacuum duct, tubing or hoses between the AIR solenoid and the AIR diverter valve	GO to HM21.

HM21 MEASURE MANIFOLD VACUUM AT THE AIR SOLENOID VALVE

Connect a vacuum gauge to the manifold vacuum hose at the AIR solenoid valve(s).
Key ON Engine RUN.

Is the manifold vacuum greater than 47 kPa (14 in-Hg)?

Yes	No
KEY OFF. GO to HM30.	KEY OFF. REPAIR the cause of the restriction

HM22 MEASURE THE VACUUM AT THE AIR DIVERTER VALVE - VACUUM RELEASE

Command outputs OFF
Exit Output Test Mode
Observe the vacuum gauge reading at the AIR solenoid valve.

Was vacuum released - 0 kPa (0 in-Hg)?

Yes	No
GO to HM23.	KEY OFF. INSTALL a new AIR solenoid.

HM23 CHECK THE AIR FLOW AT THE AIR DIVERTER VALVE(S) OUTLET

Disconnect the air hose from the AIR diverter valve(s) outlet side.
Apply 53 kPa (16 in-Hg) of vacuum at the AIR diverter valve(s).
Key ON Engine OFF.
Scan Tool Connected
Enter Output Test Mode. Refer to OUTPUT TEST MODE .
Command outputs ON
Observe air flow at the AIR diverter valve(s) outlet.
Command outputs OFF
Exit Output Test Mode

Is air flow present at the AIR diverter valve(s) outlet?

Yes	No
GO to HM24.	KEY OFF. GO to HM25.

HM24 CHECK THE AIR FLOW AT THE AIR DIVERTER VALVE(S) OUTLET. - CONTINUED

Disconnect the control vacuum hose from the AIR diverter valve(s).
Key ON Engine OFF.
Scan Tool Connected
Enter Output Test Mode. Refer to OUTPUT TEST MODE .
Command outputs ON
Observe air flow at the AIR diverter valve(s) outlet.
Command outputs OFF
Exit Output Test Mode

Is air flow present at the AIR diverter valve(s) outlet?

Yes	No
KEY OFF. REPLACE the appropriate AIR diverter valve(s).	KEY OFF. GO to HM28.

HM25 CHECK THE AIR FLOW AT THE AIR DIVERTER VALVE(S) INLET

Disconnect the air hose from the AIR diverter valve(s) inlet side.
Key ON Engine OFF.
Scan Tool Connected
Enter Output Test Mode. Refer to OUTPUT TEST MODE .
Command outputs ON
Observe air flow at the AIR diverter(s) inlet hose.
Command outputs OFF
Exit Output Test Mode

Is air flow present at the AIR diverter valve(s) inlet hose?

Yes	No
KEY OFF. REPLACE the appropriate AIR diverter valve(s).	KEY OFF. GO to HM26.

HM26 CHECK THE AIR FLOW AT THE AIR PUMP

Disconnect the air hose from the AIR pump outlet side.
Scan Tool Connected
Enter Output Test Mode. Refer to OUTPUT TEST MODE .
Command outputs ON
Observe air flow at the AIR pump outlet.
Command outputs OFF
Exit Output Test Mode

Was air flow present at the AIR pump outlet?

Yes	No
REPAIR/REPLACE as necessary the restricted air flow duct, tubing or hoses between the AIR pump and the AIR diverter valve	KEY OFF. GO to HM27.

HM27 CHECK THE AIR FLOW AT THE AIR PUMP - CONTINUED

Disconnect the air hose from the AIR pump inlet side.
INSPECT the air hose and water shield from the AIR pump inlet side for restrictions or damage.
Scan Tool Connected
Enter Output Test Mode. Refer to OUTPUT TEST MODE .
Command outputs ON
Observe air flow at the AIR pump outlet.
Command outputs OFF
Exit Output Test Mode

Was air flow present at the AIR pump outlet?

Yes	No
REPAIR/REPLACE as necessary the restricted air flow duct, tubing or hoses between the AIR pump inlet and the pump AIR water shield/silencer and/or silencer.	KEY OFF. INSTALL a new AIR motor.

HM28 CHECK THE AIR DISTRIBUTION MANIFOLD INTEGRITY AT THE EXHAUST MANIFOLD

CHECK the AIR distribution manifold at the exhaust manifold for restrictions, blockage or damage.

Is the AIR distribution manifold at the exhaust manifold restriction free?

Yes	No
GO to HM29.	REPAIR/REPLACE as necessary

HM29 CHECK FOR RESTRICTIONS IN THE EXHAUST SYSTEM

CHECK for restrictions in the exhaust system.

Is the exhaust system restriction free?

Yes	No
GO to PINPOINT TEST Z step 1 .	REPAIR/REPLACE as necessary

HM30 CHECK THE RESISTANCE OF AIR SOLENOID

AIR Solenoid connector disconnected.

Measure the resistance between:

( + )AIR Solenoid Connector, Component Side	( - )AIR Solenoid Connector, Component Side
SAIR - Pin 1	VPWR - Pin 2

Is the resistance between 50 ohms - 95 ohms?

Yes	No
GO to HM31.	INSTALL a new AIR solenoid.

HM31 CHECK THE ELECTRICAL CONNECTOR INTEGRITY

Observe the AIR Solenoid harness connector and component connector.
CHECK the electrical connector for damage, corrosion, and water ingress.

Is the connector in good working order?

Yes	No
GO to HM32.	REPAIR/REPLACE as necessary

HM32 CHECK THE VPWR VOLTAGE TO THE AIR SOLENOID

Key ON Engine OFF.

Measure the voltage between:

( + )AIR Solenoid Connector, Harness Side	( - )
VPWR - Pin 2	Ground

Is the voltage greater than 10.5 V?

Yes	No
INSTALL a new AIR solenoid.	REPAIR open circuit.

HM33 CHECK THE AIR PUMP/MOTOR ELECTRICAL CONNECTOR INTEGRITY

CHECK the AIR pump/motor electrical connector for damage, corrosion, and water ingress.
AIR Motor connector disconnected.

Is the connector in good working order?

Yes	No
GO to HM34.	REPAIR/REPLACE as necessary

HM34 CHECK THE AIR PUMP/MOTOR GROUND CIRCUIT FOR AN OPEN IN THE HARNESS

AIR Motor connector disconnected.

Measure the resistance between:

( + )AIR Motor Connector, Harness Side	( - )
AIR_GND - Pin 1	Ground

Is the resistance less than 5 ohms?

Yes	No
GO to HM35.	REPAIR open circuit.

HM35 CHECK THE B+ VOLTAGE FROM THE AIR RELAY AT THE AIR PUMP/MOTOR

l Key ON Engine OFF.
Scan Tool Connected
Enter Output Test Mode. Refer to OUTPUT TEST MODE .
Command outputs ON

Measure the voltage between:

( + )AIR Motor Connector, Harness Side	( - )
AIR_PWR - Pin 2	Ground

Command outputs OFF
Exit Output Test Mode

Is the voltage above 10.5 volts?

Yes	No
KEY OFF. INSTALL a new AIR motor.	KEY OFF. GO to HM36.

HM36 CHECK THE AIR PUMP/MOTOR FOR WATER OR ICE CONTAMINATION

NOTE: Water ingested in the AIR pump reduces the life of the pump.

Disconnect the air hose from the AIR pump inlet side.
Disconnect the air hose from the AIR pump outlet side.
AIR Motor connector disconnected.

NOTE: The AIR pump temperature must be above 0 C (32 F) degrees.

Tilt the AIR pump assembly to a range of positions to see if any water is present.

Is water or evidence of ice present in AIR pump?

Yes	No
INSTALL a new AIR motor. Carefully inspect the AIR pump hoses for proper routing and installation of the inlet water shield/silencer. REPAIR/REPLACE as necessary	INSTALL a new AIR motor.

HM37 DTC P2257: CHECK THE AIR PID OPERATION WITH OTM

CAUTION: Running the AIR pump with OTM longer than 2 minutes may overheat and damage the AIR pump. Refer to DIAGNOSTIC METHODS - CNG, FLEX-FUEL & GASOLINE , OTM).

Key ON Engine OFF.
Access the PCM -AIR PID.
Scan Tool Connected
Enter Output Test Mode. Refer to OUTPUT TEST MODE .
Observe the AIR PID while toggling the OTM state from ON to OFF.

NOTE: When the OTM outputs are commanded on, the PCM output signal AIR PID should turn on.

Command outputs ON
Command outputs OFF
Exit Output Test Mode

Does the AIR PID correspond with the OTM ON and OFF commands?

Yes	No
GO to HM38.	GO to HM47.

HM38 CHECK THE AIRM PID OPERATION WITH THE OTM

Key ON Engine OFF.
Access the PCM -AIR and PCM-AIRM PIDs.
Scan Tool Connected
Enter Output Test Mode. Refer to OUTPUT TEST MODE .
Observe the AIRM PID while toggling the OTM state from ON to OFF.

NOTE: When the OTM outputs are commanded on, the PCM output signal AIR PID should turn on followed by the PCM input signal AIRM PID. The AIRM PID indicates voltage at the AIR pump/motor.

Command outputs ON
Command outputs OFF
Exit Output Test Mode

Does the AIRM PID correspond with the OTM ON and OFF commands?

Yes	No
Unable to duplicate or identify the fault at this time. GO to HM39.	GO to HM40.

HM39 PERFORM A THOROUGH WIGGLE TEST ON THE AIR HARNESS - SAIRM LINE

Access the PCM -AIR and PCM-AIRM PIDs.

NOTE: When the OTM outputs are commanded on, the PCM output signal AIR PID should turn on followed by the PCM input signal AIRM PID. The AIRM PID indicates voltage at the AIR pump/motor.

Scan Tool Connected
Enter Output Test Mode. Refer to OUTPUT TEST MODE .
Command outputs ON
While commanding the outputs on with the OTM, wiggle the SAIRM line harness and connectors, and lightly tap the components while observing the AIRM PID.

NOTE: Changing AIRM PID states indicate a fault location in the secondary side of the AIR relay circuit. The AIRM PID indicates voltage at the AIR pump/motor.

Command outputs OFF
Exit Output Test Mode

Was a fault found?

Yes	No
KEY OFF. REPAIR/REPLACE as necessary	KEY OFF. Unable to duplicate or identify the fault at this time. GO to PINPOINT TEST Z step 1 .

HM40 CHECK THE B+ AND VPWR VOLTAGE TO THE AIR RELAY

Key OFF.
AIR Relay connector disconnected.
Key ON Engine OFF.

Measure the voltage between:

( + )AIR Relay Connector, Harness Side	( - )
B+ - Pin 30	Ground
VPWR - Pin 86	Ground

Are the voltages greater than 10.5 V?

Yes	No
GO to HM43.	KEY OFF. REPAIR open circuit. GO to HM41.

HM41 CHECK FOR AN ISOLATED B+ AIR FUSE FAULT IN THE LAST STEP

NOTE: An isolated B+ AIR fuse fault could be the result of frozen water in the AIR pump.

Was a B+ AIR fuse fault the only fault in the last step?

Yes	No
KEY OFF. GO to HM42.	KEY OFF. Stop The repair is complete

HM42 CHECK THE AIR PUMP/MOTOR FOR WATER OR ICE CONTAMINATION

NOTE: Water ingested in the AIR pump reduces the life of the pump.

Disconnect the air hose from the AIR pump inlet side.
Disconnect the air hose from the AIR pump outlet side.
AIR Motor connector disconnected.

NOTE: The AIR pump temperature must be above 0 C (32 F) degrees.

Tilt the AIR pump assembly to a range of positions to see if any water is present.

Is water or evidence of ice present in AIR pump?

Yes	No
INSTALL a new AIR motor. Carefully inspect the AIR pump hoses for proper routing and installation of the inlet water shield/silencer.	Stop The repair is complete

HM43 CHECK THE POWER CIRCUIT FROM THE AIR RELAY TO THE AIR PUMP/MOTOR FOR AN OPEN CIRCUIT

Key OFF.
AIR Motor connector disconnected.

Measure the resistance between:

( + )AIR Relay Connector, Harness Side	( - )AIR Motor Connector, Harness Side
AIR_PWR - Pin 87	AIR_PWR - Pin 2

Is the resistance less than 5 ohms?

Yes	No
GO to HM44.	REPAIR open circuit.

HM44 CHECK THE AIRM PID OPERATION WITH A JUMPER

CAUTION: Running the AIR Pump with a jumper wire longer than 2 minutes may overheat and damage the AIR pump.

Key ON Engine OFF.
Access the PCM -AIRM and PCM-AIR PIDs.
NOTE: The AIRM PID indicates voltage at the AIR pump/motor.

Connect a 5 amp fused jumper wire between the following:

Point A AIR Relay Connector, Harness Side	Point B AIR Relay Connector, Harness Side
B+ - Pin 30	AIR_PWR - Pin 87

REMOVE jumper wire(s)

Did the AIRM PID turn on with the jumper applied?

Yes	No
KEY OFF. INSTALL a new AIR relay.	GO to HM45.

HM45 CHECK THE SAIRM CIRCUIT AND THE AIR PUMP/MOTOR POWER CIRCUIT FOR SHORT(S)

Key OFF.
PCM connector disconnected.

Measure the resistance between:

( + )PCM Connector, Harness Side	( - )
SAIRM - Pin B19	Ground

Measure the resistance between:

( + )AIR Relay Connector, Harness Side	( - )
AIR_PWR - Pin 87	Ground

Is the resistance greater than 10K ohms?

Yes	No
GO to HM46.	REPAIR open circuit.

HM46 CHECK THE SAIRM CIRCUIT AND THE AIR PUMP/MOTOR POWER CIRCUIT FOR AN OPEN(S) IN THE HARNESS

Measure the resistance between:

( + )PCM Connector, Harness Side	( - )AIR Relay Connector, Harness Side
SAIRM - Pin B19	AIR_PWR - Pin 87

Measure the resistance between:

( + )PCM Connector, Harness Side	( - )AIR Motor Connector, Harness Side
SAIRM - Pin B19	AIR_PWR - Pin 2

Is the resistance less than 5 ohms?

Yes	No
INSTALL a new PCM. REFER to FLASH ELECTRICALLY ERASEABLE PROGRAMMABLE READ ONLY MEMORY - FLASH EEPROM .	REPAIR open circuit.

HM47 CHECK THE SAIR CIRCUIT(S) FOR AN OPEN IN THE HARNESS

Key OFF.
AIR Relay connector disconnected.
AIR Solenoid connector disconnected.
PCM connector disconnected.

Measure the resistance between:

( + )PCM Connector, Harness Side	( - )AIR Solenoid Connector, Harness Side
SAIR - Pin B17	SAIR - Pin 1

Measure the resistance between:

( + )PCM Connector, Harness Side	( - )AIR Relay Connector, Harness Side
SAIR - Pin B17	SAIR - Pin 85

Is the resistance less than 5 ohms?

Yes	No
GO to HM48.	REPAIR open circuit.

HM48 CHECK THE SAIR FOR SHORTS TO POWER(S) AND GROUND(S) IN THE HARNESS - DIRECT AND INDIRECT

Measure the resistance between:

( + )PCM Connector, Harness Side	( - )PCM Connector, Harness Side
SAIR - Pin B17	VPWR - Pin B35
SAIR - Pin B17	PWRGND - Pin B47
SAIR - Pin B17	SIGRTN - Pin B41
SAIR - Pin B17	VREF - Pin B40
SAIR - Pin B17	CASE GND - Pin B10

Measure the resistance between:

( + )PCM Connector, Harness Side	( - )
SAIR - Pin B17	Ground

Is the resistance greater than 10K ohms?

Yes	No
INSTALL a new PCM. REFER to FLASH ELECTRICALLY ERASEABLE PROGRAMMABLE READ ONLY MEMORY - FLASH EEPROM .	REPAIR short circuit.

HM49 DTC P2258: CHECK THE AIR PID OPERATION WITH OTM

CAUTION: Running the AIR pump with OTM longer than 2 minutes may overheat and damage the AIR pump. Refer to OUTPUT TEST MODE .

Key ON Engine OFF.
Access the PCM -AIR PID.
Observe the AIR PID(s) while toggling the OTM states from ON to OFF.
NOTE: When the OTM outputs are commanded on, the PCM output signal AIR PID should turn on.
Scan Tool Connected
Enter Output Test Mode. Refer to OUTPUT TEST MODE .
Command outputs ON
Command outputs OFF
Exit Output Test Mode

Does the AIR PID correspond with the OTM ON and OFF commands?

Yes	No
GO to HM50.	GO to HM61.

HM50 CHECK THE AIRM PID OPERATION WITH THE OTM

Scan tool connector connected.
Key ON Engine OFF.
Access the PCM -AIR and PCM-AIRM PIDs.
Observe the AIRM PID while toggling the OTM state from ON to OFF.
NOTE: When the OTM outputs are commanded on, the PCM output signal AIR PID should turn on followed by the PCM input signal AIRM PID. The AIRM PID indicates voltage at the AIR pump/motor.
Scan Tool Connected
Enter Output Test Mode. Refer to OUTPUT TEST MODE .
Command outputs ON
Command outputs OFF
Exit Output Test Mode

Does the AIRM PID correspond with the OTM ON and OFF commands?

Yes	No
GO to HM51.	GO to HM52.

HM51 PERFORM A THOROUGH WIGGLE TEST ON THE AIR HARNESS

Access the PCM -AIR and PCM-AIRM PIDs.

NOTE: When the OTM outputs are commanded on, the PCM output signal AIR PID should turn on followed by the PCM input signal AIRM PID. The AIRM PID indicates voltage at the AIR pump/motor.

Scan Tool Connected
Enter Output Test Mode. Refer to OUTPUT TEST MODE .
Command outputs ON
While commanding the outputs on with the OTM, wiggle the harness and connectors, and lightly tap the components while observing the AIRM PID.
NOTE: Changing AIRM PID states indicate a fault location in the secondary side of the AIR relay circuit. The AIRM PID indicates voltage at the AIR pump/motor.
Command outputs OFF
Exit Output Test Mode

Was a fault found?

Yes	No
KEY OFF. REPAIR/REPLACE as necessary	KEY OFF. Unable to duplicate or identify the fault at this time. GO to PINPOINT TEST Z step 1 .

HM52 REMOVE THE AIR RELAY AND OBSERVE THE AIR MONITOR PID

Key OFF.
AIR Relay connector disconnected.
Key ON Engine OFF.
NOTE: AIRM PID corresponds to PCM input SAIRM line voltage indicating voltage to the AIR pump / motor and should be in the OFF state.
Access the PCM -AIR and PCM-AIRM PIDs.

Is the AIRM PID in the OFF state?

Yes	No
GO to HM53.	GO to HM56.

HM53 CONFIRM THE SAIR SIGNAL WITH A TEST LAMP

Key ON Engine OFF.

Connect non-powered test lamp between:

( + )AIR Relay Connector, Harness Side	( - )Vehicle battery
SAIR - Pin 85	Positive terminal

Is the test lamp OFF?

Yes	No
KEY OFF. INSTALL a new AIR relay.	GO to HM54.

HM54 CHECK THE SAIR CIRCUIT FOR AN OPEN IN THE HARNESS

Key OFF.
AIR Solenoid connector disconnected.
PCM connector disconnected.

Measure the resistance between:

( + )PCM Connector, Harness Side	( - )AIR Solenoid Connector, Harness Side
SAIR - Pin B17	SAIR - Pin 1

Measure the resistance between:

( + )PCM Connector, Harness Side	( - )AIR Relay Connector, Harness Side
SAIR - Pin B17	SAIR - Pin 85

Is the resistance less than 5 ohms?

Yes	No
GO to HM55.	REPAIR open circuit.

HM55 CHECK THE SAIR LINE FOR SHORTS TO GROUND(S) IN THE HARNESS - DIRECT AND INDIRECT

Measure the resistance between:

( + )PCM Connector, Harness Side	( - )PCM Connector, Harness Side
SAIR - Pin B17	PWRGND - Pin B47
SAIR - Pin B17	VREF - Pin B40
SAIR - Pin B17	CASE GND - Pin B10

Measure the resistance between:

( + )PCM Connector, Harness Side	( - )
SAIR - Pin B17	Ground

Is the resistance greater than 10K ohms?

Yes	No
INSTALL a new PCM. REFER to FLASH ELECTRICALLY ERASEABLE PROGRAMMABLE READ ONLY MEMORY - FLASH EEPROM .	REPAIR short circuit.

HM56 CHECK FOR VOLTAGE AT THE AIR RELAY TO THE AIR PUMP\MOTOR POWER CIRCUIT

Key ON Engine OFF.

Measure the voltage between:

( + )AIR Relay Connector, Harness Side	( - )Vehicle battery
AIR_PWR - Pin 87	Negative terminal

Is the voltage less than 0.1 V?

Yes	No
KEY OFF. GO to HM60.	KEY OFF. GO to HM57.

HM57 CHECK THE AIR PUMP/MOTOR ELECTRICAL CONNECTOR INTEGRITY

CHECK the AIR pump/motor electrical connector for damage, corrosion, and water ingress.
AIR Motor connector disconnected.

Is the connector in good working order?

Yes	No
GO to HM58.	REPAIR/REPLACE as necessary

HM58 CHECK THE AIR PUMP/MOTOR GROUND CIRCUIT FOR AN OPEN IN THE HARNESS

Measure the resistance between:

( + )AIR Motor Connector, Harness Side	( - )
AIR_GND - Pin 1	Ground

Is the resistance less than 5 ohms?

Yes	No
GO to HM59.	REPAIR open circuit.

HM59 CHECK THE AIR PUMP/MOTOR FOR AN OPEN

Measure the resistance between:

( + )AIR Motor Connector, Component Side	( - )AIR Motor Connector, Component Side
AIR_GND - Pin 1	AIR_PWR - Pin 2

Is the resistance less than 10 ohms?

Yes	No
GO to HM60.	INSTALL a new AIR motor.

HM60 CHECK THE SAIR LINE FOR SHORTS TO GROUND(S) IN THE HARNESS

Measure the resistance between:

( + )PCM Connector, Harness Side	( - )PCM Connector, Harness Side
SAIR - Pin B17	PWRGND - Pin B47
SAIR - Pin B17	VREF - Pin B40
SAIR - Pin B17	CASE GND - Pin B10

Measure the resistance between:

( + )AIR Solenoid Connector, Harness Side	( - )
SAIR - Pin 1	Ground

Measure the resistance between:

( + )AIR Relay Connector, Harness Side	( - )
SAIR - Pin 85	Ground

Is the resistance greater than 10K ohms?

Yes	No
INSTALL a new PCM. REFER to FLASH ELECTRICALLY ERASEABLE PROGRAMMABLE READ ONLY MEMORY - FLASH EEPROM .	REPAIR short circuit.

HM61 CHECK THE SAIR CIRCUIT(S) FOR AN OPEN IN THE HARNESS

Key OFF.
AIR Relay connector disconnected.
AIR Solenoid connector disconnected.
PCM connector disconnected.

Measure the resistance between:

( + )PCM Connector, Harness Side	( - )AIR Solenoid Connector, Harness Side
SAIR - Pin B17	SAIR - Pin 1

Measure the resistance between:

( + )PCM Connector, Harness Side	( - )AIR Relay Connector, Harness Side
SAIR - Pin B17	SAIR - Pin 85

Is the resistance less than 5 ohms?

Yes	No
GO to HM62.	REPAIR open circuit.

HM62 CHECK THE SAIR FOR SHORTS TO POWER(S) AND GROUND(S) IN THE HARNESS - DIRECT AND INDIRECT

Measure the resistance between:

( + )PCM Connector, Harness Side	( - )PCM Connector, Harness Side
SAIR - Pin B17	VPWR - Pin B35
SAIR - Pin B17	PWRGND - Pin B47
SAIR - Pin B17	SIGRTN - Pin B41
SAIR - Pin B17	VREF - Pin B40
SAIR - Pin B17	CASE GND - Pin B10

Measure the resistance between:

( + )PCM Connector, Harness Side	( - )
SAIR - Pin B17	Ground

Is the resistance greater than 10K ohms?

Yes	No
INSTALL a new PCM. REFER to FLASH ELECTRICALLY ERASEABLE PROGRAMMABLE READ ONLY MEMORY - FLASH EEPROM .	REPAIR short circuit.