Measure resistance between pin 14 of the CCRM harness connector and chassis ground.
Is resistance greater than 10,000 ohms? Yes
REPLACE CCRM. VERIFY applicable FAN PWR circuit is not shorted to ground.
No
REPAIR short circuit.
X80 LOW AND/OR HIGH SPEED COOLING FAN ALWAYS RUNS (NO DTCS): VERIFY FAN IS NOT ON BECAUSE OF A/C HIGH PRESSURE SWITCH INPUT TO PCM
Start engine.
Access ACP PID.
Is the ACP PID "CLOSED"? Yes
The PCM will turn the cooling fan on when the A/C high pressure switch input is "closed". Leave engine running. GO to X81
.
No
Input OK. GO to X82
.
X81 CHECK A/C HIGH PRESSURE SWITCH (THE MEDIUM PRESSURE, NORMALLY OPEN CONTRACTS)
Disconnect A/C high pressure switch.
Again, view the ACP PID on scan tool.
Is the ACP PID still "CLOSED"? Yes
KEY OFF. GO to X135
(to check A/C high pressure switch input to PCM).
No
KEY OFF. RECONNECT A/C high pressure switch. REFER to the Heating and Air Conditioning to check for proper A/C high pressure switch function, over-pressurized A/C system and other checks as directed.
X82 DISCONNECT CCRM AND CHECK IF FAN STILL RUNS
Accessories off (A/C, blower, lamps).
Key on, verify cooling fan always on symptom.
Key off.
Disconnect CCRM.
Key on, engine off.
Is cooling fan still on? Yes
KEY OFF.
For 3.8L Mustang:
REPAIR FAN PWR circuit short to power.
For all others:
GO to X83
.
No
Key off. GO to X84
.
X83 CHECK LOW FAN PWR AND HIGH FAN PWR CIRCUITS FOR SHORT TO POWER
Disconnect cooling fan.
Key on, engine off.
Check for voltage on both the LOW FAN PWR and HIGH FAN PWR circuits at the cooling fan harness connector.
Are both voltages less than 1.0 volt? Yes
KEY OFF. No fault is indicated at this time. VERIFY results of previous
X84 CHECK OPERATION OF LOW SPEED FAN OR HIGH SPEED FAN PRIMARY CIRCUITS
Note: The symptom cooling fan always runs can be caused by a primary circuit fault, even though a DTC was not set. This step will check the primary circuit operation.
Reconnect CCRM.
Key on, engine off.
Access LFC and LFCF PIDs. With LFC PID off (low speed fan commanded off by PCM), the LFCF PID must be no.
For all except 3.8L Mustang, access HFC and HFCF PIDs. With HFC PID off (high speed fan commanded off by PCM), the HFCF PID must be no.
Is the HFCF or LFCF PID yes with the fan commanded off? Yes
KEY OFF. An HFC or LFC primary circuit fault is detected.
If the HFCF PID was yes:
GO to X15
and follow DTC P1479 diagnosis.
If the LFCF PID was yes:
GO to X20
and follow DTC P1474 diagnosis.
No
Primary circuits OK. REPLACE CCRM.
X98 LACK OF COOLING (A/C)/A/C NOT FUNCTIONING: CHECK FOR VOLTAGE TO A/C CLUTCH
Note: If the A/C clutch will engage, follow the "YES" Action to Take of this test step. If not, or unsure, continue this test step.
Key off.
Disconnect A/C cycling switch.
Install a jumper wire in the A/C cycling switch harness connector (to complete the circuit).
Disconnect A/C clutch.
Connect digital multimeter between the power pin and ground pin at the A/C clutch vehicle harness connector.
Start engine.
Turn A/C on, wait 15 seconds.
Check voltage reading.
After testing, turn key off and reconnect A/C clutch.
Was voltage greater than 10.5 volts? Yes
REMOVE jumper. RECONNECT A/C cycling switch.
For all except 3.8L Mustang with the symptom "poor A/C system performance in hot ambient temperature":
GO to X145
to check A/C high pressure switch input to PCM.
All others:
REFER to the Heating and Air Conditioning. Also be aware
that if the engine coolant temperature is detected high, the PCM will
disengage the A/C clutch.
No
No voltage to A/C clutch. GO to X99
.
X99 CHECK ACCS INPUT TO PCM WITH A/C ON
Start engine.
A/C on.
Access and view ACCS PID.
After testing, remove jumper reconnect A/C cycling switch and turn key OFF.
Was the ACCS PID "ON"? Yes
GO to X110
.
No
The PCM is not receiving the ACCS signal, and as a result will not allow the A/C to turn on. GO to X100
.
X100 ACCS PID OFF WITH A/C ON: CHECK FOR VOLTAGE TO A/C CYCLING SWITCH
Key on, engine off.
Disconnect A/C cycling switch.
A/C demand switch to A/C on.
Measure voltage at the A/C demand switch side of the A/C cycling switch harness connector.
Is voltage greater than 10.5 volts? Yes
KEY OFF. GO to X101
.
No
KEY OFF. REFER to the Heating and Air Conditioning to check for causes of no voltage to the A/C cycling switch.
X101 CHECK IF A/C CYCLING SWITCH CONTACTS ARE CLOSED
Measure resistance of the A/C cycling switch contacts at the A/C cycling switch connector.
Is resistance less than 5.0 ohms? Yes
GO to X102
.
No
REFER to the Heating and Air Conditioning to check the operation of the A/C cycling switch and proper refrigerant charge. REPAIR as necessary.
X102 CHECK FOR VOLTAGE TO DUAL FUNCTION A/C HIGH PRESSURE SWITCH
Reconnect A/C cycling switch.
Disconnect A/C high pressure switch.
Key on, engine off.
A/C on.
Measure voltage on the A/C demand switch pin at the A/C high pressure switch harness connector.
Is voltage greater than 10.5 volts?
Yes
KEY OFF. GO to X103
.
No
REPAIR open between A/C cycling switch and A/C high pressure switch.
X103 CHECK RESISTANCE OF A/C HIGH PRESSURE SWITCH HIGH PRESSURE CONTACTS
Measure resistance of the normally closed A/C high pressure switch high pressure contacts.
Is resistance less than 5.0 ohms?
Yes
GO to X104
.
No
REFER to the Heating and Air Conditioning to check for overpressurized A/C system,etc. If OK, REPLACE A/C high pressure switch, following instructions in the Heating and Air Conditioning.
REPAIR open circuit between the A/C high pressure switch and PCM.
X105 KOEO/KOER DTC P1460: VERIFY ACCS PID IS OFF
Note: Verify A/C and Defrost were off during KOEO/KOER Self-Test. If vehicle is not equipped with A/C, the WAC circuit is not used and the DTC P1460 can be ignored.
Start engine.
A/C and defroster off.
Access ACCS PID.
Is the ACCS PID off? Yes
KEY OFF. GO to X106
.
No
KEY OFF. GO to X125
(to check A/C circuits for short to power).
X106 CHECK WAC CIRCUIT AND WOT A/C CUTOFF RELAY IN CCRM
Disconnect CCRM.
Check WOT A/C cutoff relay coil resistance:
Measure resistance between pin 22 and pin 24 of the CCRM.
Resistance must be between 130 and 200 ohms.
Check CCRM for internal short circuit:
Measure resistance of CCRM between pin 22 and the following pins: 1 through 11, 13, 15 and 21.
Measure resistance between pin 22 and the CCRM case.
Measure resistance of A/C clutch PWR circuit between pin 23 of the CCRM harness connector and the A/C clutch harness connector.
Measure resistance of A/C clutch ground circuit between pin 16 of the CCRM harness connector and the A/C clutch harness connector.
Are both resistances less than 5.0 ohms? Yes
VERIFY engine is not overheating when there is no voltage to A/C clutch
(if engine coolant temperature is high, the PCM will turn off the A/C).
If OK, REPLACE CCRM. VERIFY A/C Clutch PWR circuit is not shorted to
ground.
No
REPAIR open circuit.
X115 DTC P1469: CHECK FOR CAUSES OF FAST A/C COMPRESSOR CLUTCH CYCLING
Refer to the Heating and Air Conditioning to test A/C compressor clutch cycle times, and to check causes of fast A/C compressor clutch cycling.
Is a fault indicated? Yes
REPAIR as required according to diagnostic/repair information direction. CLEAR the
DTCs. START engine and turn A/C on for about 2 minutes. A/C off. RERUN
Quick Test.
No
GO to X116
to CHECK for intermittent electrical concern.
X116 CHECK FOR INTERMITTENT OPEN IN ACCS CIRCUIT
Key on.
Access ACCS PID.
A/C on.
Observe ACCS PID for an indication of a fault while completing the following (the ACCS PID will turn off and on quickly when a fault is detected, indicating an intermittent open):
Shake, wiggle, bend the ACCS circuit between the PCM and the source of the circuit (such as A/C switch, EATC module).
Lightly tap any pressure switches in the circuit to simulate road shock.
Disconnect and inspect the A/C cycling switch connector.
Is a fault indicated? Yes
KEY OFF. ISOLATE fault and REPAIR as necessary. CLEAR the DTCs. START
engine and TURN A/C on for about two minutes. A/C off. RERUN Quick Test.
Note: Verify A/C and defrost were off during Self-Test. If A/C or defrost were on, turn off and rerun Self-Test.
Key on, engine off.
A/C and defrost off.
Access ACCS PID.
Is ACCS PID on? Yes
GO to X125
.
No
The ACCS PID indicates that the ACCS input to the PCM is low. VERIFY
test results. With A/C and defrost off, RERUN Self-Test where DTC P1464
was received.
X125 ACCS PID ON: DISCONNECT A/C CYCLING SWITCH AND CHECK IF ACCS PID TURNS OFF
Disconnect A/C cycling switch.
Key on, engine off.
Access ACCS PID.
Is ACCS PID off? Yes
KEY OFF. VERIFY operation of A/C demand switch (REFER to the Heating and Air Conditioning). If OK, REPAIR short to power in A/C demand circuit to A/C
cycling switch.
No
KEY OFF.
For Escort:
GO to X127
.
All others:
GO to X126
.
X126 CHECK A/C CLUTCH PWR CIRCUIT FOR SHORT TO POWER IN HARNESS
Disconnect CCRM.
Key on.
Measure voltage between pin 23 of the CCRM harness connector and ground.
Is voltage less than 1.0 volt? Yes
KEY OFF. GO to X127
.
No
REPAIR short circuit. RESTORE vehicle. VERIFY a symptom no longer exists.
X127 CHECK ACCS CIRCUIT FOR SHORT TO POWER IN HARNESS
Key off.
A/C cycling switch and CCRM (except Escort) disconnected.
Disconnect PCM.
Key on.
Measure voltage between PCM harness connector pin 41 and ground.
Is voltage less than 1.0 volt? Yes
For Escort:
REPLACE PCM.
All others:
KEY OFF. GO to X128
.
No
REPAIR short circuit.
X128 CHECK ACCS CIRCUIT VOLTAGE TO PCM WITH CCRM CONNECTED
Reconnect CCRM.
Key on.
Again, measure voltage between PCM harness connector pin 41 and ground.
Is voltage less than 1.0 volt? Yes
REPLACE PCM.
No
REPLACE CCRM.
X130 DOES THE A/C TURN OFF WHEN THE A/C DEMAND SWITCH IS TURNED OFF?
Does the A/C turn off when the A/C demand switch is turned off? Yes
GO to X131
.
No
GO to X140
.
X131 CHECK IF A/C CUTS OFF DURING WOT
Start engine.
A/C on.
Initiate brief Wide Open Throttle (WOT) and return to idle. Listen for the A/C clutch to disengage during the WOT, then re-engage a few seconds after returning to idle (a "click" sound will be heard when the clutch re-engages).
Note: If the clicking sound cannot be heard, disconnect the A/C clutch. With a test lamp connected between the power pin and ground pin of the A/C clutch harness connector, observe the test lamp while performing the brief WOT. The test lamp must go off during the brief WOT, then come back on a few seconds after returning to idle.
Repeat test, if necessary, to verify results.
Does A/C clutch or test lamp operate as indicated? Yes
KEY OFF. RECONNECT A/C clutch (if necessary). The WAC circuit is
KEY OFF. REFER to the Heating and Air Conditioning.
No
KEY OFF. GO to X125
.
X145 CHECK A/C HIGH PRESSURE SWITCH MEDIUM PRESSURE CIRCUITS
Note: An A/C high pressure switch medium pressure circuit concern can result in the high speed cooling fan not coming on when the A/C refrigerant pressure becomes high. In hot ambient conditions, this may result in the refrigerant pressure continuing to increase until the A/C high pressure switch high pressure contacts open, shutting off the A/C until the pressure drops to an acceptable range.
Key off.
Disconnect A/C high pressure switch.
A/C off (to prevent chance of short circuits).
Connect a jumper wire between the A/C high pressure switch circuit and ground circuit at the A/C high pressure switch harness connector.
Start engine, wait 15 seconds.
Does the high speed fan come on?
Yes
KEY OFF. A/C high pressure switch medium pressure circuits are OK.
REMOVE jumper. RECONNECT A/C high pressure switch.
No
An A/C high pressure switch medium pressure circuit concern may exist. GO to X146
.
X146 CHECK FOR OPEN GROUND CIRCUIT TO A/C HIGH PRESSURE SWITCH
Key on, engine running.
Connect jumper wire between the A/C high pressure switch circuit at the A/C high pressure switch harness connector and the battery negative post.
Wait 15 seconds.
Does the high speed fan come on now? Yes
KEY OFF. REPAIR open ground circuit to the A/C high pressure switch. REMOVE jumper wire.
No
KEY OFF. REMOVE jumper wire. GO to X147
.
X147 CHECK FOR OPEN A/C HIGH PRESSURE SWITCH (ACPSW) CIRCUIT BETWEEN A/C HIGH PRESSURE SWITCH AND PCM
Disconnect PCM.
Measure resistance of the ACPSW circuit between the PCM harness connector pin 86 and the A/C high pressure switch harness connector.
