Ford F150 Pickup. Instruction - part 1498

Inspect engine for obvious defects in specified systems. Repair as necessary. If no faults are found, go to 
TEST DC, step 25). 

42) Perform KOER Self-Test 
 
Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC). Disconnect fuel 
vapor hose from intake manifold and plug fitting at intake manifold. Start engine, and operate at 2000 
RPM for 5 minutes, then allow to return to idle. Perform KOER ON-DEMAND SELF-TEST and 
proceed as follows: 

z

If KOER DTCs P0040, P0041, P1127, P1128 or P1129 are present, go to appropriate system test. 
See DIAGNOSTIC TROUBLE CODE DEFINITIONS.  

z

If KOER DTC (P1131, P2195) or (P1151, P2197) is present, go to next step.  

z

If KOER DTC (P1132, P2196) or (P1152, P2198) is present, go to step 49).  

If none of these DTCs are present, proceed as follows:  

z

If Continuous Memory DTC P0171, P0172, P0174 or P0175 is present, go to step 52).  

z

If DTCs P1132, P2196 and/or P1152, P2198 are no longer present, reconnect fuel vapor hose.  

z

If directed to this test to diagnose DTCs P1131, P1132, P1151 and/or P1152, perform evaporative 
system leakage tests. See EVAPORATIVE EMISSIONS DIAGNOSTIC TROUBLE CODE 
DEFINITIONS.  

z

If no DTCs have repeated and no DTCs are present, fault is unable to be duplicated at this time. Go 
to TEST Z, step 1).  

43) HO2S Circuit Test (With Lean DTCs) 
 
Disconnect HO2S harness connector that is related to DTC retrieved. Turn ignition switch to ON 
position. Using scan tool, access appropriate HO2S PID (11, 12, 21 or 22) from PID/DATA MONITOR 
& RECORD menu. Connect a jumper wire between HO2S SIG and VPWR circuits at suspect HO2S 
harness connector. 

If HO2S PID voltage is 1.3 volt or more, check SIG RTN circuit for open. Go to next step. If voltage is 
less than 1.3 volt, go to step 46). 

44) Check SIG RTN Circuit For Open 
 
Turn ignition switch to OFF position. Using a DVOM, measure resistance of SIG RTN circuit between 
negative battery terminal and suspect HO2S harness connector. See Fig. 233. If resistance is less than 5 
ohms, reconnect HO2S and go to step 52). If resistance is 5 ohms or more, go to next step. 

45) Check HO2S SIG RTN Circuit For Open In Harness 
 
Ensure ignition switch is in OFF position and PCM connector(s) is disconnected. Using a DVOM, 

NOTE:

If spark occurs when connecting jumper wire (indicating a short circuit), 
remove jumper wire, check fuse in HO2S HTR circuit and go to step 47).

 

2003 Ford Pickup F150 

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

  

measure resistance of SIG RTN circuit between PCM harness connector and suspect HO2S harness 
connector. See PCM HO2S, PWR GND & VPWR CIRCUIT TERMINAL IDENTIFICATION 
table. See PCM CONNECTOR IDENTIFICATION and Fig. 233. If resistance is less than 5 ohms, 
replace PCM. If resistance is 5 ohms or more, repair open in SIG RTN circuit. 

46) Check HO2S SIG Circuit For Open 
 
Turn ignition switch to OFF position. Disconnect PCM connector(s). Inspect connectors for loose, 
damaged or corroded terminals. Repair as necessary. Ensure suspect HO2S harness connector is 
disconnected. Using a DVOM, measure resistance of HO2S SIG circuit between suspect HO2S harness 
connector and appropriate PCM harness connector. See PCM HO2S, PWR GND & VPWR CIRCUIT 
TERMINAL IDENTIFICATION table. See PCM CONNECTOR IDENTIFICATION and Fig. 233. 
If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in SIG RTN 
circuit. 

47) Check HO2S SIG Circuit For Short To Ground 
 
Turn ignition switch to OFF position. Disconnect PCM connector(s). Ensure suspect HO2S harness 
connector is disconnected. Using a DVOM, measure resistance between HO2S SIG, and PWR GND and 
HO2S SIG RTN circuits at PCM harness connector. See PCM HO2S, PWR GND & VPWR CIRCUIT 
TERMINAL IDENTIFICATION table. See PCM CONNECTOR IDENTIFICATION. If both 
resistance measurements are more than 10 k/ohms, go to next step. If either resistance measurement is 10 
k/ohms or less, repair short between affected circuits. 

48) Check HO2S For Short To Ground 
 
Leave PCM disconnected. Reconnect suspect HO2S connector. Using a DVOM, measure resistance 
between HO2S SIG, and PWR GND and HO2S SIG RTN circuits at PCM harness connector. See PCM 
HO2S, PWR GND & VPWR CIRCUIT TERMINAL IDENTIFICATION table. See PCM 
CONNECTOR IDENTIFICATION. If both resistance measurements are 10 k/ohms or less, replace 
faulty HO2S. If both resistance measurements are more than 10 k/ohms, replace PCM. 

49) Check HO2S Circuit (Rich DTCs) 
 
Ensure ignition switch is in OFF position. Disconnect HO2S harness connector that is related to DTC 
retrieved. Turn ignition switch to ON position. Using scan tool, access appropriate HO2S PID (11, 12, 21 
or 22) from PID/DATA MONITOR & RECORD menu. If HO2S PID voltage is more than .2 volt, go to 
next step. If HO2S PID voltage is .2 volt or less, go to step 51). 

50) Check HO2S SIG Circuit For Short To VPWR & HO2S HTR Circuits 
 
Turn ignition switch to OFF position. Disconnect PCM connector(s). Inspect connector for loose, 
damaged or corroded terminals. Repair as necessary. Using a DVOM, measure resistance between HO2S 
SIG, and VPWR and HO2S HTR circuits at PCM harness connector. See PCM HO2S, PWR GND & 
VPWR CIRCUIT TERMINAL IDENTIFICATION table. See PCM CONNECTOR 
IDENTIFICATION. If both resistance measurements are more than 10 k/ohms, replace PCM. If either 
resistance measurement is 10 k/ohms or less, repair short between affected circuits. 

 

2003 Ford Pickup F150 

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

  

51) Check HO2S SIG For Short To HO2S HTR Circuit In Sensor 
 
Turn ignition switch to OFF position. Ensure suspect HO2S harness connector is disconnected. Using a 
DVOM, measure resistance between HO2S SIG and HO2S HTR circuits at suspect HO2S connector. See 
Fig. 233. If resistance measurement is more than 10 k/ohms, go to next step. If resistance measurement is 
10 k/ohms or less, replace internally shorted HO2S. 

52) Check Fuel Pressure 
Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC). Release fuel 
system pressure. See FUEL SYSTEM PRESSURE RELEASE procedure under FUEL SYSTEMS in 
appropriate REMOVAL & INSTALLATION article. Install fuel pressure gauge. Using scan tool, access 
OUTPUT TEST MODE. See OUTPUT TEST MODE under ADDITIONAL SYSTEM FUNCTIONS. 
Command fuel pump ON and run fuel pump to obtain maximum fuel pressure. Record fuel pressure. 
Compare measured fuel pressure to fuel pressure specification in illustration. See Fig. 167. If fuel system 
pressure is not as specified, go to TEST HC, step 1). If fuel system pressure is as specified, go to next 
step. 

53) Check Fuel System For Pressure Stability With Ignition On (Slow Leakdown) 
 
With fuel pressure gauge installed, cycle ignition from OFF to ON position 3-4 times to pressurize fuel 
system (DO NOT start engine). Note fuel pressure with ignition switch turned to ON position. If fuel 
pressure does not remain within 5 psi (34 kPa) of maximum pressure after 10 seconds, check fuel system 
for external leaks. If an external leak is detected, go to TEST HC, step 1). If an external leak is not 
detected, go to step 55). If fuel pressure remains within 5 psi (34 kPa) of maximum pressure after 10 
seconds, go to next step. 

54) Check Fuel System For Pressure Stability With Ignition ON 
 
With fuel pressure gauge installed, cycle ignition from OFF to ON position 3-4 times to pressurize fuel 
system (DO NOT start engine). Note fuel pressure with ignition switch turned to ON position. If fuel 
pressure remains within 5 psi (34 kPa) of maximum pressure after one minute, go to TEST HC, step 5). If 
fuel pressure does not remain within 5 psi (34 kPa) of maximum pressure after one minute, go to step 56) 
(for HO2S DTCs displayed with Misfire DTCs), or go to step 59) (for all other DTCs). 

55) Check Injector Fault PIDs & Associated DTCs 

WARNING:

Always refer to safety procedures to reduce possibility of injury. See 
FUEL SYSTEM SAFETY PRECAUTIONS.

NOTE:

Fuel pump will only operate for 8 seconds when OUTPUT TEST MODE is 
activated.

NOTE:

For additional information on Misfire DTCs and setting conditions, go to 
MISFIRE DETECTION MONITORING under DIAGNOSTIC MONITORING 
TESTS under ADDITIONAL SYSTEM FUNCTIONS.

 

2003 Ford Pickup F150 

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

  

Turn ignition switch to ON position. Using scan tool, access INJ1F-INJ10F PIDs from PID/DATA 
MONITOR & RECORD menu. If misfire DTCs are present (P0301-P0310), only select injector fault PID
(s) that correspond to appropriate misfire DTC(s). If DTCs P0201-P0212 or an injector fault(s) is present, 
go to next step. If no injector fault is present and only Misfire DTCs P0300-P0310 are present, go to 
TEST HD, step 12). If DTCs P0201-P0212 are not present, no injector fault(s) are present, and any other 
DTC is present, go to step 

59)

. 

56) For KOEO, KOER & Continuous Memory DTC P0201-P0212: Check Fuel Injector & Circuit 
Resistance 
The Comprehensive Component Monitor (CCM) monitors the operation of the fuel injector drivers in the 
PCM. The test fails when the fuel injector does not operate electrically even though the harness assembly 
and fuel injectors test satisfactorily. Possible cause is a faulty fuel injector driver within the PCM. 

Turn ignition switch to OFF position. Disconnect PCM connector(s). Inspect connector for loose, 
damaged or corroded terminals. Repair as necessary. Use injector fault PID noted in step 55) to determine 
fuel injector circuits that require testing. Using a DVOM, measure and record resistance between suspect 
fuel injector circuit and VPWR circuits at PCM harness connector. See PCM FUEL INJECTOR, PWR 
GND & VPWR CIRCUIT TERMINAL IDENTIFICATION table. See PCM CONNECTOR 
IDENTIFICATION. Resistance should be 11-18 ohms. If resistance is not as specified, go to next step. 
If resistance is as specified, concern may be intermittent. Go to TEST Z, step 1). If unable to duplicate 
concern, replace PCM. 

PCM FUEL INJECTOR, PWR GND & VPWR CIRCUIT TERMINAL IDENTIFICATION 

57) Check Fuel Injector Harness Resistance 
 
Turn ignition switch to OFF position. Disconnect suspect fuel injector harness connector. Using a 
DVOM, measure resistance of fuel injector circuit signal and VPWR circuit between PCM harness 
connector and suspect fuel injector harness connector. See PCM FUEL INJECTOR, PWR GND & 
VPWR CIRCUIT TERMINAL IDENTIFICATION table. See PCM CONNECTOR 

NOTE:

For additional testing information, see DIAGNOSTIC AIDS.

NOTE:

Performing this test step will clear Continuous Memory DTCs.

Injector No. 104-Pin PCM Terminal No. 122-Pin PCM Terminal No. 150-Pin PCM Terminal No.
1

75

E14

E2

2

101

E15

E14

3

74

E7

E24

4

100

E8

E32

5

73

E3

E11

6

99

E4

E21

7

72

E5

E29

8

98

E6

E37

9

68

N/A

N/A

10

42

N/A

N/A

 

2003 Ford Pickup F150 

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