Ford F150 Pickup. Manual — part 1585

Fig. 373: Identifying Constant Control Relay Module Circuits (Mustang 4.6L)
Courtesy of FORD MOTOR CO.

2003 Ford Pickup F150

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

Fig. 374: Identifying Constant Control Relay Module Circuits (ZX2)
Courtesy of FORD MOTOR CO.

2003 Ford Pickup F150

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

Fig. 375: Identifying Constant Control Relay Module Connector Terminals
Courtesy of FORD MOTOR CO.

CCRM LOCATIONS

Testing

Application

Location

Mustang

Mounted On Bracket, Behind Engine Coolant Reservoir

ZX2

In Left Front Of Engine Compartment

2003 Ford Pickup F150

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

1) Check For Open VPWR Circuit Between IAC Valve & CCRM
Turn ignition switch to OFF position. Disconnect fuel injector and CCRM connectors. See CCRM
LOCATIONS table. Disconnect scan tool from Data Link Connector (DLC). Using a DVOM, measure
resistance of VPWR circuit between fuel injector harness connector and CCRM harness connector
terminals No. 12 and 24. See Fig. 372-Fig. 375 . If both resistances are less than 5 ohms, reconnect fuel
injector and go to next step. If both resistances are 5 ohms or more, repair open in VPWR circuit between
CCRM and splice to fuel injector. See WIRING DIAGRAMS.

2) Check B+ Voltage & IGN START/RUN Voltage To CCRM

Using a DVOM, measure voltage between negative battery terminal and B+ circuit at CCRM harness
connector terminals No. 8 and 10. Note voltage. Turn ignition switch to ON position. Using a DVOM,
measure voltage between negative battery terminal and IGN START/RUN circuit at CCRM harness
connector terminal No. 13. If all voltages are more than 10.5 volts, go to next step. If any voltage
measurement is 10.5 volts or less, check related fuses. If fuse is blown, check for short to ground in B+ or
IGN START/RUN circuit. Repair as necessary and replace fuse. If fuses are okay, repair open in B+ or
IGN START/RUN circuit.

3) Check CCRM GND Circuit

Turn ignition switch to OFF position. Leave CCRM disconnected. Using a DVOM, measure voltage
between terminals No. 8 (VPWR) and No. 15 (GND) at CCRM harness connector. If voltage is more than
10.5 volts, replace CCRM. If voltage is 10.5 volts or less, repair open in GND circuit to CCRM.

15) For KOEO & KOER Only DTC P0481 & P1479: Check HFC Control Relay & HFC Circuit In
CCRM
DTC P0481 or P1479 is set when PCM detects a High Speed Fan Control (HFC) primary circuit failure.
Possible causes are:

z

Open Or Shorted HFC Circuit

z

Open VPWR Circuit To HFC Relay

z

Faulty CCRM (HFC Relay Or Internal Circuit)

z

Faulty Powertrain Control Module (PCM)

Turn ignition switch to OFF position. Disconnect CCRM connector. See CCRM LOCATIONS table.
Using a DVOM, measure HFC relay coil resistance between CCRM terminals No. 17 (HFC) and No. 24
(VPWR). See Fig. 375. Resistance should be 65-110 ohms. Also, measure CCRM internal resistance
between terminal No. 17 and terminals No. 1-11, 13 and 21, and CCRM case. Measure resistance of

NOTE:

Diagnostic procedures beginning with step 1) are performed when
directed here from TEST C, step 5), or TEST HX, step 76).

NOTE:

A break in step numbering sequence occurs at this point. Procedure skips
from step 3) to step 15). No test procedures have been omitted.

NOTE:

On single speed cooling fan applications, ignore DTC P1479.

2003 Ford Pickup F150

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