Ford F150 Pickup. Instruction - part 1575

1) For KOEO, KOER & Continuous Memory DTC P1229: Check VPWR To CAC Pump Relay 
Coil 
DTC P1229 is set when PCM is requesting CAC pump motor to operate, but voltage is not detected on 
CAC circuit. Possible causes are: 

z

Internal Open In CAC Pump Motor  

z

B+ Or VPWR Circuit Open Or Shorted To Ground  

z

CAC Or CAC PUMP PWR Circuit Open Or Shorted To Ground  

z

Faulty CAC Pump Relay  

z

CAC Pump Motor Shorted  

z

Bad CAC Pump Motor Ground Connection  

z

Faulty PCM  

Turn ignition switch to OFF position. Disconnect CAC pump relay. Turn ignition switch to ON position. 
Using a DVOM, measure VPWR circuit voltage at the CAC pump relay harness connector. If the voltage 
is greater than 10.5 volts, go to next step. If voltage is 10.5 volts or less, repair open circuit. 

2) Check CAC Pump Relay 
 
Turn ignition switch to OFF position. Remove CAC pump relay from battery junction box in engine 
compartment. Using a DVOM, measure resistance between relay terminals No. 1 and 2. Resistance 
should be 90-110 ohms. Measure resistance between relay terminal No. 1 and all other relay terminals. 
Resistance should be more than 10 k/ohms. See Fig. 307 and Fig. 353 . If resistance is as specified, go to 
next step. If resistance is not as specified, replace CAC relay. 

3) Check For Open CAC Circuit Between PCM & CAC Relay 
 
Ensure ignition switch is in OFF position. Disconnect PCM connector. Inspect connector for loose, 
damaged or corroded terminals. Repair as necessary. Using a DVOM, measure resistance of CAC circuit 
(White/Orange wire) between PCM harness connector and CAC pump relay cavity. See PCM 
CONNECTOR IDENTIFICATION and Fig. 353. If resistance is less than 5 ohms, go to next step. If 
resistance is 5 ohms or more, repair open in CAC circuit. 

4) Check CAC Circuit Between PCM & CAC Pump Relay For Short To PWR 
 
Ensure CAC relay is removed from battery junction box in engine compartment. Turn ignition switch to 
ON position. Using a DVOM, measure voltage between negative battery terminal and CAC circuit at 
PCM harness connector. If voltage is less than .05 volt, go to next step. If voltage is .05 volt or more, 
repair short to B+ or VPWR in CAC circuit. 

5) Check CAC Circuit Between PCM & CAC Pump Relay For Short To Ground 
 
Turn ignition switch to OFF position. Using a DVOM, measure resistance between negative battery 
terminal and CAC circuit (White/Orange wire) at PCM harness connector. See PCM CONNECTOR 

NOTE:

For additional testing information, see DIAGNOSTIC AIDS.

 

2003 Ford Pickup F150 

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

  

IDENTIFICATION and Fig. 353. If resistance is more than 10 k/ohms, go to next step. If resistance is 
10 k/ohms or less, repair short to ground in CAC circuit. 

6) Check Status Of SCICP PID 
Ensure ignition switch is turned to OFF position. Reconnect PCM connector. Reinstall CAC relay and 
fuses No. 23 and 106. Turn ignition switch to ON position. Using scan tool, access SCICP PID from 
PID/DATA MONITOR & RECORD menu. If SCICP PID value indicates OFF, check for intermittent 
faults. Go to TEST Z, step 1). If SCICP PID value indicates ON, proceed as follows: 

z

Check CAC reservoir level.  

z

Check for air flow blockage at CAC radiator.  

z

Check for high resistance or open circuit in Intake Air Temperature (IAT) 2 sensor and connecting 
circuits.  

z

Check for reversed intercooler hoses.  

Repair as necessary. If no concerns are found and DTC P1229 is present in KOEO and KOER self-test, 
replace PCM. 

7) Check Charge Air Cooler Pump Operation 
Turn ignition switch to OFF position. Using scan tool, access OUTPUT TEST MODE. See OUTPUT 
TEST MODE under ADDITIONAL SYSTEM FUNCTIONS. Select mode ALL ON. If charge air 
intercooler pump runs, check for low fluid level in intercooler system, check for cracked or incorrectly 
routed intercooler lines or airflow blockage at the CAC radiator. Repair as necessary. If symptom still 
exists, see appropriate TROUBLE SHOOTING - NO CODES article. If charge air intercooler pump does 
not run, go to next step. 

8) Check Power And Ground Circuits At CAC Pump Motor 
 
Turn ignition switch to OFF position. Disconnect the CAC pump. Connect scan tool to DLC. Turn 
ignition switch to ON position. Using scan tool, access OUTPUT TEST MODE. See OUTPUT TEST 
MODE under ADDITIONAL SYSTEM FUNCTIONS. Select mode ALL ON. Using DVOM, measure 
the voltage across the CAC pump motor harness connector. If the voltage is greater than 10.5 volts, 
replace CAC pump motor. If the voltage is 10.5 volts or less, go to next step. 

9) Check Integrity Of CAC Pump Ground Connection 
 
Turn ignition switch to OFF position. Disconnect the CAC pump. Using a DVOM, measure the resistance 
between chassis ground circuit at the CAC pump connector and battery negative terminal. If the 
resistance is less than 5 ohms, go to next step. If the resistance is 5 ohms or more, check the tightness of 
the ground lug. If tight, check wire back to the CAC connector. 

NOTE:

On some scan tools, SCICP PID may indicate ICP PID.

NOTE:

Step 7) is performed when directed here from symptom under SYMPTOMS 
in TROUBLE SHOOTING - NO CODES - CNG, FLEX-FUEL & GASOLINE 
article.

 

2003 Ford Pickup F150 

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

  

10) Check B+ To CAC Pump Relay 
 
Disconnect CAC pump relay. Using a DVOM, measure B+ circuit voltage at the CAC pump relay 
connector. If voltage is greater than 10.5 volts, go to next step. If voltage is 10.5 volts or less, B+ circuit 
has a fault. Check condition of related fuses. If fuses are okay, repair open circuit. If fuse is damaged, 
check B+ and CAC pump motor circuits for short to ground before replacing. 

11) Check For Open CAC Pump Motor Circuit 
 
Using a DVOM, measure resistance of the CAC pump motor circuit between the CAC pump motor relay 
harness connector and the pump motor harness connector. If the resistance is less than 5 ohms, replace 
CAC pump motor relay. If resistance is 5 ohms or more, repair open circuit.  

TEST KQ: THERMOSTAT HEATER CONTROL 

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

Thermostat  

z

Wiring Harness Circuits (THTRC & VPWR)  

z

Powertrain Control Module (PCM)  

NOTE:

After each service or repair procedure has been completed, reconnect all 
components. Clear DTCs and repeat QUICK TEST procedures to ensure all EEC-
V systems are working properly

 

2003 Ford Pickup F150 

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

  

Fig. 354: Identifying Thermostat Heater Control Harness Connector Terminals 
Courtesy of FORD MOTOR CO. 

Testing 

10) For KOEO, KOER & Continuous Memory DTCs P0597 & P1432: Check VPWR To THTRC 
Harness Connector 
DTC P0597 or P1432 is set when PCM detects THTRC circuit voltage below a calibrated limit for a 
calibrated time during Comprehensive Component Monitor (CCM). Possible causes are: 

z

THTRC Circuit Open Or Shorted To B+, GND Or VPWR  

z

VPWR Circuit Open  

NOTE:

Procedure starts from step 10). 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