Ford F150 Pickup. Instruction - part 1521

10) Check AIR Diverter Valve Integrity 
Turn ignition switch to OFF position. Disconnect air tube from diverter valve(s) outlet side. Check 
diverter valve outlet(s) for heat damage and repair if necessary. Using hand vacuum pump, apply 16 in. 
Hg (54 kPa) of vacuum to AIR diverter valve(s). Turn ignition switch to ON position. Using scan tool, 
enter OUTPUT TEST MODE. If air is present from AIR diverter valve(s), turn ignition switch to OFF 
position and check exhaust tube(s) from AIR diverter valve to exhaust manifold(s). If exhaust tube(s) 
from diverter valve are okay, go to next step. If air is not present from AIR diverter valve(s), turn ignition 
switch to OFF position and check hose from EAIR pump to AIR diverter valve(s). Replace as necessary. 
If hose is okay, replace appropriate AIR diverter valve(s). 

11) Check Manifold Vacuum With Exhaust Manifold Disconnected 
Disconnect exhaust pipe from exhaust manifold. Install vacuum gauge to intake manifold port (if not 
done previously). Start engine and gradually raise engine speed to 2000 RPM. Observe vacuum gauge 
reading response while maintaining increased engine RPM. If manifold vacuum increases quickly to 16 
in. Hg (54 kPa) as increased RPM is maintained, exhaust system is free of restrictions. Exhaust restriction 
is downstream of exhaust manifold. Reconnect exhaust system to exhaust manifold and go to next step. If 
manifold vacuum is low or slow to respond, restriction is present in exhaust manifold. Check exhaust 
manifold for restrictions. If restrictions are present and are unable to be removed, replace exhaust 
manifold. 

12) Check Manifold Vacuum With Muffler & Tailpipe Assembly Disconnected For Indication Of A 
Restriction 
 
Disconnect muffler and tailpipe assembly from catalytic converter. Start engine and gradually raise 
engine speed to 2000 RPM. Observe vacuum gauge reading response while maintaining increased engine 
RPM. If vacuum gauge needle moves quickly to more than 16 in. Hg (54 kPa) with engine speed 
increased, restriction is in muffler and tailpipe assembly. Repair as necessary. If vacuum gauge needle 
does not move quickly to more than 16 in. Hg (54 kPa) with engine speed increased, restriction is in 
catalytic converter. Replace catalytic converter. After replacing catalytic converter, check muffler and 
tailpipe assembly for debris from faulty catalytic converter. 

13) Check Voltage On EAIR Monitor Circuit 
 
Connect scan tool to Data Link Connector (DLC). Turn ignition switch to OFF position. Disconnect 
EAIR pump. Turn ignition switch to ON position. Using scan tool, enter OUTPUT TEST MODE. Using 
a DVOM, measure voltage between negative battery terminal and SAIRM circuit at EAIR pump harness 
connector. See Fig. 249. If voltage is more than 10.5 volts, go to step 15). If voltage is 10.5 volts or less, 
go to next step. 

14) Check EAIR Pump GND Circuit For Open In Harness 
 
Using a DVOM, measure resistance of GND circuit between EAIR pump harness connector and negative 
battery terminal. See Fig. 249. If resistance is less than 5 ohms, go to step 21). If resistance is 5 ohms or 
more, repair open in GND circuit. 

NOTE:

An intake manifold gasket leak can cause vacuum gauge reading to 
remain below normal range.

 

2003 Ford Pickup F150 

2003 ENGINE PERFORMANCE Self-Diagnostics - CNG, Flex-Fuel & Gasoline

  

15) Check Air Hose To EAIR Pump 
 
Disconnect air inlet hose to EAIR pump. Check hose for cracks, binding, obstructions, water or ice (in 
colder climates). Drain water from air hose, repair, reposition or replace hose as necessary and go to step 
17). If hose is okay, go to step 17). 

16) Check Solid State Relay Output 
 
Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC). Reconnect AIR 
by-pass solenoid. Reconnect PCM harness connector. Ensure SSR is connected. Turn ignition switch to 
ON position. Using scan tool, enter OUTPUT TEST MODE. Access AIR and AIRM PIDs from 
PID/DATA MONITOR & RECORD menu. Compare AIR and AIRM PID readings. If both PID readings 
indicate ON, replace SSR. If either PID value indicates OFF, fault may be intermittent. Go to TEST Z, 
step 2) to check for intermittent faults. If no intermittent faults are found, replace PCM. 

17) Check Air Pump For Water 
Turn ignition switch to OFF position. Disconnect EAIR pump air hoses and harness connector. Carefully 
tilt EAIR pump at various angles to check for water. If water is present, replace EAIR pump. If water is 
not present proceed as follows: 

z

If fuse was replaced in step 6), testing is complete.  

z

On all others, go to step 9).  

19) For KOEO, KOER & Continuous Memory DTC P1413: Check B+ Circuit Voltage To Solid 
State Relay 
DTC P1413 indicates SAIRM circuit is low (EAIR pump OFF) although PCM is commanding EAIR 
pump ON. Possible causes are: 

z

B+ Circuit Open  

z

EAIRM Circuit Open Or Short To GND  

z

Faulty PCM  

z

Faulty EAIR Pump  

z

Faulty Solid State Relay (SSR)  

Turn ignition switch to OFF position. Disconnect SSR harness connector. Turn ignition switch to ON 
position. Using a DVOM, measure voltage between chassis ground and B+ circuit at SSR harness 
connector. See Fig. 249. If voltage is more than 10.5 volts, go to next step. If voltage is 10.5 volts or less, 
go to step 26). 

NOTE:

Water contamination in EAIR pump will shorten life of pump.

NOTE:

A break in step numbering sequence occurs at this point. Procedure skips 
from step 17) to step 19). No test procedures have been omitted.

NOTE:

For additional testing information, see DIAGNOSTIC AIDS.

 

2003 Ford Pickup F150 

2003 ENGINE PERFORMANCE Self-Diagnostics - CNG, Flex-Fuel & Gasoline

  

20) Check VPWR Voltage To SSR 
 
Turn ignition switch to ON position. Using a DVOM, measure voltage between chassis ground and 
VPWR circuit at SSR harness connector. See Fig. 249. If voltage is more than 10.5 volts, go to next step. 
If voltage is 10.5 volts or less, go to TEST B, step 5) (LS V6), or repair open in VPWR circuit between 
PCM power relay and SSR (all others). 

21) Check Voltage On EAIR Monitor (SAIRM) Circuit 
 
Turn ignition switch to OFF position. Ensure scan tool is connected to Data Link Connector (DLC). 
Reconnect SSR harness connector. Disconnect EAIR pump connector. Turn ignition switch to ON 
position. Using scan tool, enter OUTPUT TEST MODE. See OUTPUT TEST MODE under 
ADDITIONAL SYSTEM FUNCTIONS. Access AIRM PID. If AIRM PID value indicates ON, remain in 
OUTPUT TEST MODE and go to step 25). If AIRM PID value indicates OFF and DTC P0411 is present, 
replace EAIR pump, remain in OUTPUT TEST MODE and go to next step. 

22) Check SAIRM Circuit Voltage To PCM 
 
Ensure ignition switch is in ON position. Using scan tool, access AIRM PID from PID/DATA 
MONITOR & RECORD menu. If AIRM PID value indicates ON, replace PCM. If AIRM PID value 
indicates OFF, go to next step. 

23) Check EAIR Driver & SAIRM Circuits For Open In Harness 
 
Turn ignition switch to OFF position. Disconnect SSR and EAIR pump harness connectors. Using a 
DVOM, measure resistance of EAIR driver circuit and SAIRM circuit between PCM harness connector 
and SSR harness connector. Using a DVOM, measure resistance of SAIRM circuit between SSR harness 
connector and EAIR pump harness connector. See Fig. 249. If any resistance measurement is 5 ohms or 
more, repair open in affected circuit. If all resistance measurements are less than 5 ohms, go to next step. 

24) Check EAIRM Circuit For Short To Ground 
 
Using a DVOM, measure resistance between EAIRM and PWR GND circuits at PCM harness connector. 
See Fig. 249. If resistance measurement is more than 10 k/ohms, replace SSR. If resistance measurement 
is 10 k/ohms or less, repair short between circuits. 

25) Check EAIRM Circuit Voltage To PCM 
 
Reconnect EAIR pump and PCM harness connectors. Turn ignition switch to ON position. Ensure scan 
tool is still in OUTPUT TEST MODE and all outputs are selected ON. Using scan tool, access AIRM 
PID. If AIRM PID value indicates ON, replace PCM. If AIRM PID value indicates OFF, repair open in 
EAIR circuit. 

26) Check B+ Circuit For Open In Harness 
 
Using a DVOM, measure resistance of B+ circuit between SSR harness connector and SSR dedicated B+ 
circuit fuse. See Fig. 249. If resistance is less than 5 ohms, replace SSR dedicated fuse. If resistance is 5 

 

2003 Ford Pickup F150 

2003 ENGINE PERFORMANCE Self-Diagnostics - CNG, Flex-Fuel & Gasoline

  

ohms or more, repair open in B+ circuit. 

27) For KOEO, KOER & Continuous Memory DTC P1414 & P2257: Check EAIRM Circuit For 
Open In Harness 
DTC P1414 indicates SAIRM circuit is high (EAIR pump is ON) although PCM is commanding EAIR 
pump OFF. Possible causes are: 

z

SAIRM Circuit Open  

z

EAIR Circuit Shorted To PWR  

z

Faulty Solid State Relay (SSR)  

z

Open EAIR Pump GND  

z

Faulty EAIR Pump  

z

Faulty PCM  

Turn ignition switch to OFF position. Disconnect EAIR pump, SSR harness connector and PCM 
connector(s). Using a DVOM, measure resistance of SAIRM circuit between PCM harness connector and 
EAIR pump harness connector. See PCM CONNECTOR IDENTIFICATION and Fig. 249. If 
resistance is 5 ohms or more, repair open in SAIRM circuit. If resistance is less than 5 ohms, go to next 
step. 

28) Check EAIR Pump For Open 
 
Using a DVOM, measure resistance between both EAIR pump terminals. If resistance is 0.5-5.0 ohms, go 
to next step. If resistance is not 0.5-5.0 ohms, replace EAIR pump. 

29) Check SAIRM Circuit For Short To PWR In Harness 
 
Turn ignition switch to ON position. Using a DVOM, measure voltage between chassis ground and 
SAIRM circuit at PCM harness connector. See Fig. 249. If voltage is more than 10.5 volts, repair short to 
PWR in SAIRM circuit. If voltage is 10.5 volts or less, SAIRM circuit is okay. Go to next step. 

30) Check Solid State Relay Output 
 
Reconnect all connectors. Connect scan tool to Data Link Connector (DLC). Turn ignition switch to ON 
position. Using scan tool, access OUTPUT TEST MODE. See OUTPUT TEST MODE under 
ADDITIONAL SYSTEM FUNCTIONS. Access AIR and AIRM PIDs. Observe PID values. If both PID 
values indicate ON, replace SSR. If either PID value indicates OFF, replace PCM. 

32) Check Vacuum Hose Integrity 
 
Turn ignition switch to OFF position. Remove vacuum hose between intake manifold and AIR diverter 

NOTE:

For additional testing information, see DIAGNOSTIC AIDS.

NOTE:

A break in step numbering sequence occurs at this point. Procedure skips 
from step 30) to step 32). No test procedures have been omitted.

 

2003 Ford Pickup F150 

2003 ENGINE PERFORMANCE Self-Diagnostics - CNG, Flex-Fuel & Gasoline