X: Constant Control Relay Module (CCRM)

X: Introduction See: X: Constant Control Relay Module (CCRM) - Introduction

X1 VPWR CHECK AT IAC VALVE FAILED IN PINPOINT TEST C: CHECK FOR OPEN VPWR CIRCUIT BETWEEN IAC VALVE AND CCRM

• Disconnect IAC valve.
• Disconnect CCRM.
• Disconnect scan tool from DLC.
• Measure resistance of VPWR circuit between IAC valve harness connector and pins 12 and 24 (VPWR) of the CCRM harness connector.

Is either resistance less than 5.0 ohms?
Yes

• RECONNECT IAC valve. GO to X2

.

No

• BOTH resistances GREATER than 5.0 ohms. REPAIR open VPWR circuit between the CCRM and the splice to the IAC valve.

X2 CHECK B+ AND IGN START/RUN VOLTAGE TO CCRM

• Measure voltage to Pin 8 and Pin 10 (B+) of the CCRM harness connector.
• Key on, engine off.
• Measure voltage to Pin 13 (IGN START/RUN) of the CCRM harness connector.

Are all voltages greater than 10.5 volts?
Yes

• KEY OFF. GO to X3

.

No

• B + or IGN START/RUN circuit fault. CHECK condition of related fuse(s).

If OK, REPAIR open circuit. If fuse is damaged, CHECK IGN START/RUN or
B+ and VPWR circuits for short to ground before replacing.

X3 CHECK CCRM GROUND CIRCUIT

• Measure voltage between pin 8 (B+) and pin 15 (GND) at the CCRM harness connector.

Is voltage greater than 10.5 volts?
Yes

• REPLACE CCRM.

No

• REPAIR open ground circuit to CCRM (pin 15).

X15 DTC P1479: CHECK HIGH SPEED FAN CONTROL (FC) RELAY AND HFC CIRCUIT IN CCRM

Note: For one-speed fan applications, disregard DTC P1479.

• Disconnect CCRM.
• Check high speed FC relay coil resistance:
• Measure resistance between pin 17 and pin 24 of the CCRM.
• Resistance must be between 65 and 100 ohms.
• Check CCRM for internal shorts:
• Measure resistance of CCRM between pin 17 and the following pins: 1 through 11, 13, 15 and 21.
• Measure resistance between pin 17 and the CCRM case.
• Each resistance must be greater than 1,000 ohms.

Are the CCRM checks OK?
Yes

• GO to X16

.

No

• REPLACE CCRM.

X16 CHECK FOR OPEN HFC CIRCUIT

• Disconnect PCM.
• Measure resistance of HFC circuit between PCM harness connector and pin 17 of CCRM harness connector.

Is resistance less than 5.0 ohms?

• GO to X17

.

No

• REPAIR open circuit.

X17 CHECK HFC CIRCUIT FOR SHORT TO POWER IN HARNESS

• Key on.
• Measure voltage between HFC circuit at PCM harness connector and chassis ground.

Is voltage less than 1.0 volt?
Yes

• KEY OFF. GO to X18

.

No

• REPAIR short circuit.

X18 CHECK HFC CIRCUIT FOR SHORT TO GROUND IN HARNESS

• Disconnect scan tool from DLC.
• Measure resistance between HFC circuit at PCM harness connector and chassis ground.

Is resistance greater than 10,000 ohms?
Yes

• If DTC P1479 was received in Quick Test:
• CONNECT scan tool to DLC. Key on, engine off. Access Output Test

Mode on scan tool. Command high speed fan on, wait 10 seconds, then
turn fan off. If high speed fan turns on, and off as expected, disregard
P1479 and return to Section 3. See: Symptom Related Diagnostic Procedures If fan does not operate correctly, REPLACE PCM (refer to Section 2, Flash Electrically Erasable Programmable Read Only Memory (EEPROM) See: Programming and Relearning\Flash Electrically Eraseable Programmable Read Only Memory - Flash EEPROM).

• All others:
• REPLACE CCRM. VERIFY HIGH FAN PWR circuit is not short to ground.

No

• REPAIR short circuit.

X20 DTC P1474: DOES FAN RUN WITH KEY ON?

Note: During diagnosis, FC applies to the fan control circuit (single-speed fans), and LFC applies to the low fan control circuit (two-speed fans).
Does the cooling fan always run with the key on?
Yes

• KEY OFF. GO to X24

.

No

• KEY OFF. GO to X21

.

X21 CHECK FC/LFC CIRCUIT FOR SHORT TO GROUND IN HARNESS

• Disconnect scan tool from DLC.
• Disconnect PCM.
• Disconnect CCRM.
• Measure resistance between pin 14 of the CCRM harness connector and chassis ground.

Is resistance greater than 10,000 ohms?
Yes

• GO to X22

.

No

• REPAIR short circuit.

X22 CHECK FAN RUNNING MODE

• Connect CCRM.
• Key on, engine off.

Is fan running with the key on?
Yes

• REPLACE PCM (refer to Section 2, Flash Electrically Erasable Programmable Read Only Memory (EEPROM) See: Programming and Relearning\Flash Electrically Eraseable Programmable Read Only Memory - Flash EEPROM).

No

• REPLACE CCRM.

X24 CHECK FOR OPEN FC/LFC CIRCUIT IN HARNESS

• Disconnect PCM.
• Disconnect CCRM.
• Measure resistance of the FC/LFC circuit between PCM harness connector and pin 14 of the CCRM harness connector.

Is resistance less than 5.0 ohms?

• GO to X25

.

No

• REPAIR open circuit.

X25 CHECK FC/LFC CIRCUIT FOR SHORT TO POWER IN HARNESS

• Key on.
• Measure voltage between pin 14 of the CCRM harness connector and chassis ground.

Is voltage less than 1.0 volt?
Yes

• KEY OFF. GO to X26

.

No

• REPAIR short circuit.

X26 FC/LFC CIRCUIT FAULT ISOLATION CHECK

• Reconnect CCRM.
• Jumper FC/LFC circuit at PCM harness connector to chassis ground.
• Key on, engine off.

Does fan continue to run?
Yes

• KEY OFF. REPLACE CCRM.

No

• KEY OFF. REPLACE PCM (refer to Section 2, Flash Electrically Erasable Programmable Read Only Memory (EEPROM) See: Programming and Relearning\Flash Electrically Eraseable Programmable Read Only Memory - Flash EEPROM).

X30 CONTINUOUS MEMORY DTC P1474: CHECK FAN CONTROL (FC) OR LOW FAN CONTROL (LFC) CIRCUIT FOR OPEN OR SHORT TO POWER

• Disconnect cooling fan connector.
• Connect a non-powered test lamp between the (LOW) FAN PWR circuit and ground circuit at the cooling fan harness connector.
• Key on, engine off.
• Observe test lamp for an indication of a fault while completing the following (since the FC/LFC circuit is grounded to turn the fan OFF, the lamp will illuminate when an open or short to power is detected):
• Shake, wiggle, bend the FC/LFC circuit between the PCM and CCRM.
• Lightly tap on the CCRM to simulate road shock.

Is a fault indicated?
Yes

• KEY OFF. ISOLATE fault and REPAIR as necessary.

No

• GO to X31

.

X31 CHECK FC/LFC CIRCUIT FOR SHORT TO GROUND

• Key on, engine off.
• Access Output Test Mode on scan tool.
• Command Low Speed Fan on.
• Observe test lamp for an indication of a fault while completing the following (the lamp will turn off when a fault is detected, indicating a short to ground or an open in VPWR):
• Shake, wiggle, bend the FC/LFC circuit between the PCM and CCRM.
• Lightly tap on the CCRM to simulate road shock.

Is a fault indicated?
Yes

• ISOLATE fault and REPAIR as necessary.

No

• KEY OFF. GO to Z1 See: Diagnostic Trouble Code Tests and Associated Procedures\SECTION 5: Pinpoint Tests\Z: Intermittent - Pinpoint Test

.

X35 DTC P1479: CHECK HIGH FAN CONTROL (HFC) CIRCUIT FOR OPEN OR SHORT TO POWER

Note: For one-speed fan applications, disregard DTC P1479.

• Disconnect cooling fan connector. Inspect connector for damaged or pushed out pins, corrosion and loose wires. Repair as necessary.
• Connect a non-powered test lamp between the HIGH FAN PWR circuit and ground circuit at the cooling fan harness connector.
• Key on, engine off.
• Access Output Test Mode on scan tool.
• Command high speed fan on.
• Observe test lamp for an indication of a fault while completing the following (the lamp will turn off when a fault is detected, indicating an open or short to power):
• Shake, wiggle, bend the HFC circuit between the PCM and CCRM.
• Lightly tap on the CCRM to simulate road shock.

Is a fault indicated?
Yes

• KEY OFF. ISOLATE fault and REPAIR as necessary.

No

• GO to X36

.

X36 CHECK HFC CIRCUIT FOR SHORT TO GROUND

• Key on, engine off.
• Command high speed fan off.
• Observe test lamp for an indication of a fault while completing the following (the lamp will turn on when a fault is detected, indicating a short to ground):
• Shake, wiggle, bend the HFC circuit between the PCM and CCRM.
• Lightly tap on the CCRM to simulate road shock.

Is a fault indicated?
Yes

• ISOLATE fault and REPAIR as necessary. RESTORE vehicle.

No

• KEY OFF. GO to Z1 See: Diagnostic Trouble Code Tests and Associated Procedures\SECTION 5: Pinpoint Tests\Z: Intermittent - Pinpoint Test

.

X40 ELECTRIC COOLING FAN FUNCTIONAL CHECK

Note: For the proper results of these pinpoint tests, no DTCs must have been present during PCM Quick Test.

• Key on, engine off.
• Access Output Test Mode on scan tool.
• Command of the cooling fan on and check for fan operation. For two speed fan applications, check both fan speeds (wait 30 seconds after commanding high speed fan on).

Does the fan operate (all speeds)?
Yes

• KEY OFF. Cooling fan circuits OK. RETURN to Section 3 See: Symptom Related Diagnostic Procedures.

No

• COMMAND cooling fan off. REMAIN in Output Test Mode. GO to X41

.

X41 ELECTRIC COOLING FAN CONCERN: DID THE FAN OPERATE AT ANY SPEED?

• For 3.8L Mustang, GO to X42.

During the operational check of both fan speeds, did the fan operate at any speed?
Yes

• Only one fan speed is operational.
• GO to X50

.

No

• Cooling fan will not operate at any speed. GO to X42

.

X42 COOLING FAN WILL NOT OPERATE AT ANY SPEED: COMMAND FAN ON (HIGH SPEED FOR TWO-SPEED APPLICATIONS) AND CHECK FOR VOLTAGE AT FAN

• Key on, engine off.
• Disconnect cooling fan.
• Command fan on (high speed for two speed fan applications).
• Measure voltage between the (HIGH) FAN PWR circuit at the cooling fan harness connector and chassis ground.

Is voltage greater than 10.0 volts?
Yes

• KEY OFF. Power is being supplied to fan. GO to X45

.

No

• KEY OFF. GO to X43

.

X43 CHECK FOR B+ TO FAN CONTROL RELAYS IN CCRM

• Disconnect CCRM.
• Measure voltage at pins 3 and 4 of the CCRM harness connector.

Is voltage greater than 10.0 volts?
Yes

• GO to X44

.

No

• B+ fault. CHECK condition of related fuses. If OK, REPAIR open circuit.

If fuse is damaged, CHECK B+ and FAN PWR circuits for short to ground
before replacing.

X44 CHECK FOR OPEN FAN PWR CIRCUIT BETWEEN CCRM AND COOLING FAN

• For 3.8L Mustang:
• Measure resistance of FAN PWR circuit between pin 2 of the CCRM harness connector and the fan harness connector.
• All others:
• Measure resistance of HIGH FAN PWR circuit between pin 6 of the CCRM harness connector and the fan harness connector.
• Measure resistance of LOW FAN PWR circuit between pin 2 of the CCRM harness connector and the fan harness connector.

Is each resistance less than 7.0 ohms?
Yes

• For 3.8L Mustang:
• GO to X70

.

• All others:
• REPLACE CCRM. VERIFY FAN PWR circuit(s) are not short to ground.

No

• REPAIR open circuits(s).

X45 CHECK FOR OPEN COOLING FAN GROUND CIRCUIT

• Disconnect scan tool from DLC.
• Measure resistance of ground circuit between the cooling fan harness connector and chassis ground.

Is resistance less than 5.0 ohms?
Yes

• REPLACE fan.

No

• REPAIR open circuit.

X50 DETERMINE WHICH FAN SPEED IS OPERATIONAL

Was the low speed fan operational?
Yes

• High speed fan inoperative.
• GO to X65

.

No

• Low speed fan inoperative.
• GO to X51.

X51 LOW SPEED FAN INOPERATIVE: COMMAND LOW SPEED FAN ON AND CHECK FOR VOLTAGE TO COOLING FAN

• Key on, engine off.
• Disconnect cooling fan.
• Command low speed fan on.
• Measure LOW FAN PWR circuit voltage at the cooling fan harness connector.

Is voltage greater than 10.0 volts?
Yes

• KEY OFF.
• For 4.6L Mustang:
• GO to X54

.

• All others:
• REPLACE fan.

No

• KEY OFF. GO to X52

.

X52 CHECK FOR OPEN LOW FAN PWR CIRCUIT BETWEEN CCRM AND FAN

• Disconnect CCRM.
• Measure resistance of the LOW FAN PWR circuit between the cooling fan harness connector and pins 1 and 2 of the CCRM harness connector.

Are both resistances less than 5.0 ohms?
Yes

• GO to X70

.

No

• REPAIR open circuit.

X54 CHECK FOR OPEN DROPPING RESISTOR ON FAN SHROUD ASSEMBLY

• Measure resistance between the LOW FAN PWR and HIGH FAN PWR pins of the fan shroud assembly.

Is resistance less than 6.0 ohms?
Yes

• REPLACE fan.

No

• Verify condition of dropping resistor, replace as necessary (use care

when removing resistor from mounts). If OK, replace fan assembly.

X65 HIGH SPEED FAN INOPERATIVE: COMMAND HIGH SPEED FAN ON AND CHECK FOR VOLTAGE TO COOLING FAN

• Key on, engine off.
• Disconnect cooling fan.
• Command high speed fan on.
• Measure HIGH FAN PWR circuit voltage at the cooling fan harness connector.

Is voltage greater than 10.5 volts?
Yes

• KEY OFF. REPLACE fan.

No

• KEY OFF. GO to X66

.

X66 CHECK FOR OPEN HIGH FAN PWR CIRCUIT

• Disconnect CCRM.
• Measure resistance of HIGH FAN PWR circuit between the cooling fan harness connector and pin 6 of the CCRM harness connector.

Is resistance less than 5.0 ohms?
Yes

• GO to X70

.

No

• REPAIR open circuit.

X70 IS SCAN TOOL CAPABLE OF VIEWING PIDS WHILE IN OUTPUT TEST MODE?

Note: The symptom low speed fan or high speed fan inoperative can be caused by a primary circuit fault, even though a DTC was not set.
Is scan tool being used capable of viewing PIDS while in Output Test Mode?
Yes

• GO to X71

.

No

• For low speed fan inoperative (fan inoperative for 3.8L Mustang):
• GO to X73

.

• For high speed fan inoperative.
• GO to X16

.

Continued: See: X71 - X147