Ford F150 Pickup. Instruction - part 1522

valve(s). Check hose for cracks, blockage, restrictions, kinks, poor connections, obstructions or water or 
ice (in colder climates). Replace or repair hose as necessary. If hose is okay, go to next step. 

33) Check AIR By-Pass Solenoid Electrical Operation 
 
Ensure scan tool is connected to DLC. Disconnect air by-pass solenoid connector. Turn ignition switch to 
ON position. Using scan tool, access OUTPUT TEST MODE. Connect DVOM between both AIR by-
pass solenoid harness connector terminals. See Fig. 249. Observe DVOM voltage reading while cycling 
outputs first ON, and then OFF. If voltage reading cycles more than 0.5 volt, remain in OUTPUT TEST 
MODE and go to next step. If voltage reading does not cycle more than 0.5 volt, turn ignition switch to 
OFF position and go to step 35). 

34) Check AIR By-Pass Solenoid For Mechanical Operation 
 
Ensure scan tool is in OUTPUT TEST MODE. Reconnect AIR by-pass solenoid harness connector. 
Disconnect source vacuum hose from AIR by-pass solenoid. Connect hand vacuum pump to vacuum 
source side of AIR by-pass solenoid. Apply 16 in. Hg (54 kPa) to AIR by-pass solenoid. Observe DVOM 
while cycling outputs ON and OFF. If vacuum does not release as outputs are cycled ON and OFF, 
replace AIR by-pass solenoid. If vacuum releases as outputs are cycled ON and OFF, repair vacuum hose 
between AIR by-pass solenoid and intake manifold vacuum tree. If hose is okay, go to TEST Z, step 2). 

35) Check Air By-Pass Solenoid Resistance 
 
Turn ignition switch to OFF position. Disconnect AIR by-pass solenoid harness connector. Using a 
DVOM, measure resistance between both AIR by-pass solenoid terminals. If resistance is 50-100 ohms, 
go to next step. If resistance is not 50-100 ohms, replace AIR by-pass solenoid. 

36) Check VPWR Circuit For Open In Harness 
 
Turn ignition switch to ON position. Using a DVOM, measure voltage between negative battery terminal 
and VPWR circuit at AIR by-pass solenoid 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, repair open in VPWR circuit. On LS V6, ensure 
dedicated B+ circuit fuse is okay. 

37) Check EAIR Circuit For Open In Harness 
 
Turn ignition switch to OFF position. Disconnect SSR and PCM connector(s). Using a DVOM, measure 
resistance of EAIR circuit between PCM harness connector, AIR by-pass solenoid harness connector and 
SSR harness connector. See PCM CONNECTOR IDENTIFICATION and Fig. 249. If any resistance 
measurement is 5 ohms or more, repair open in EAIR circuit. If both resistance measurements are less 
than 5 ohms, go to next step. 

38) Check EAIR Circuit For Short To Ground In Harness 
 
Turn ignition switch to OFF position. Using a DVOM, measure resistance between EAIR and PWR GND 
circuits at PCM harness connector. See PCM PWR GND, SIG RTN & VREF TERMINAL 
IDENTIFICATION table. See PCM CONNECTOR IDENTIFICATION and Fig. 249. If resistance 

 

2003 Ford Pickup F150 

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

  

measurement is more than 10 k/ohms, go to next step. If resistance measurement is 10 k/ohms or less, 
repair short between circuits. 

39) Check EAIR Circuit For Short To PWR In Harness 
 
Using a DVOM, measure resistance between EAIR, and PWR and VREF circuits at PCM harness 
connector. See PCM PWR GND, SIG RTN & VREF TERMINAL IDENTIFICATION table. See 
PCM CONNECTOR IDENTIFICATION and Fig. 249. If resistance is more than 10 k/ohms, replace 
PCM. If resistance is 10 k/ohms or less, repair short between circuits.  

TEST HU: AIR INTAKE SYSTEM 

Diagnostic Aids 

Perform this test when instructed during QUICK TEST or if directed by other test procedures. This test is used 
to diagnose the following:  

z

Throttle Body Assembly  

z

Speed Control Cable  

z

Accelerator Linkage To Throttle Body  

z

Air Cleaner Assembly (Including Element)  

z

Air Inlet Tube  

z

Clean Air Tube & Resonator  

z

Intake Manifold Runner Control (IMRC) Assembly  

z

IMRC Actuator Assembly  

z

Intake Manifold Swirl Control (IMSC) Actuator Assembly  

z

Wiring Harness Circuits (IMRC Or IMSC, IMRC Or IMSC MONITOR, SIG RTN, PWR GND, VREF & 
VPWR)  

z

Intake Manifold Tuning (IMT) Valve  

z

Powertrain Control Module (PCM)  

NOTE:

After each service or repair procedure has been completed, reconnect all 
components. Go to step 38) and perform IMRC Or IMSC REPAIR VERIFICATION 
DRIVE CYCLE to ensure all EEC-V systems are working properly and DTCs are 
no longer present.

NOTE:

Intake Manifold Runner Control (IMRC), Intake Manifold Swirl Control (IMSC) 
and Swirl Control Valve Monitor (SCVM) will be referred to as IMRC, IMSC or 
SCVM throughout diagnostic procedures. See Fig. 251-Fig. 255 .

 

2003 Ford Pickup F150 

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

  

Fig. 251: Identifying IMRC Wiring Harness Connector Terminals (Aviator) 
Courtesy of FORD MOTOR CO. 

Fig. 252: Identifying IMRC Actuator Wiring Harness Connector Terminals (Focus 2.0L 2V) 
Courtesy of FORD MOTOR CO. 

 

2003 Ford Pickup F150 

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

  

Fig. 253: Identifying IMRC Wiring Harness Connector Terminals (Econoline & Pickup 4.2L, & Mustang 
& Windstar) 
Courtesy of FORD MOTOR CO. 

Fig. 254: Identifying IMSC Wiring Harness Connector Terminals (Ranger 2.3L) 
Courtesy of FORD MOTOR CO. 

 

2003 Ford Pickup F150 

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