HX: Evaporative Emission (EVAP) Monitor and System

HX: Introduction See: HX: Evaporative Emission (EVAP) Monitor and System - Introduction

Continued from: See: HX1 - HX35

HX36 CHECK OPPOSITE INDUCED LOW FTP SIGNAL

• Connect a jumper wire between SIG RTN and FTP circuits at the FTP sensor harness connector.
• Key on, engine off.
• If a scan tool communication concern exists, turn the key off, remove jumper immediately and GO to HX41.
• Access FTP V PID.
• If FTP V PID is not present on the scan tool, measure voltage between FTP and SIG RTN circuits at the PCM harness connector with PCM connected.

Is measured voltage or FTP V PID reading less than 0.10 volt?
Yes

• REMOVE jumper. GO to HX37

.

No

• Unable to induce opposite signal. KEY OFF. GO to HX39

.

HX37 CHECK FOR IN RANGE VOLTAGE BETWEEN VREF AND SIG RTN CIRCUITS AT FTP SENSOR

• Key on, engine off.
• Measure voltage between VREF and SIG RTN circuits at the FTP sensor vehicle harness connector.

Is voltage between 4.0 and 6.0 volts?
Yes

• KEY OFF. GO to HX38

.

No

• VREF voltage is out of range. GO to C1 See: C: Reference Voltage - Pinpoint Test

.

HX38 CHECK FTP CIRCUIT FOR SHORT TO VREF IN SENSOR OR HARNESS

Note: Refer to the PCM connector pin numbers in the beginning of this pinpoint test.

• Disconnect PCM.
• Measure resistance between FTP and VREF circuits at the PCM harness connector. (For 150PIN PCM, measure to both VREF pins.)

Is the resistance greater than 10,000 ohms?
Yes

• REPLACE FTP sensor. REFER to Evaporative Emissions System for component removal and installation. RESTORE

vehicle. FOLLOW the Vehicle Preparation for Monitor Repair Verification Drive
Cycle and COMPLETE an Evaporative Emission Leak Check Monitor Repair Verification
Drive Cycle (REFER to Section 2, Drive Cycles See: Diagnostic Trouble Code Tests and Associated Procedures\SECTION 2: Diagnostic Methods\Drive Cycles).

No

• REPAIR short circuit.

HX39 CHECK FTP CIRCUIT FOR OPEN IN HARNESS

Note: Refer to the PCM connector pin numbers in the beginning of this pinpoint test.

• Disconnect PCM.
• Measure resistance of FTP circuit between PCM harness connector pin and FTP sensor harness connector.

Is resistance less than 5.0 ohms?
Yes

• GO to HX40

.

No

• REPAIR open circuit.

HX40 CHECK FOR OPEN SIG RTN CIRCUIT BETWEEN PCM AND FTP SENSOR

• Measure resistance of SIG RTN circuit between PCM harness connector pin and FTP sensor harness connector.

Is resistance less than 5.0 ohms?
Yes

• GO to HX41

.

No

• REPAIR open circuit.

HX41 CHECK FTP CIRCUIT FOR SHORT TO VREF IN PCM

• PCM disconnected.
• Measure resistance between FTP and VREF circuits at the PCM harness connector. (For 150 PIN PCM, measure to both VREF pins.)

Is the resistance greater than 10,000?
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

• REPAIR short circuit.

HX43 DTC P0457: CHECK FOR MISSING OR LEAKING FUEL FILLER CAP

• Check for missing fuel filler cap.
• Check for a loose fuel filler cap.
• Check for possible cross-thread fuel filler cap condition.

Is a concern present with the proper installation of the fuel filler cap?
Yes

• REPLACE cross-threaded or damaged fuel filler cap. RECONNECT

and TIGHTEN the fuel filler cap only one-eighth turn so that the cap initially
clicks by sound or touch. COMPLETE PCM KAM Reset to clear DTCs and adaptive
memory. (REFER to Section 2, Diagnostic Methods See: Diagnostic Trouble Code Tests and Associated Procedures\SECTION 2: Diagnostic Methods\Diagnostic Methods).
COMPLETE an Evaporative Emission Leak Check Monitor Repair Verification Drive
Cycle (REFER to Section 2, Drive Cycles See: Diagnostic Trouble Code Tests and Associated Procedures\SECTION 2: Diagnostic Methods\Drive Cycles).
RERUN Quick Test. If DTC P0455 is present, REFER to Evaporative Emissions System.

No

• COMPLETE PCM KAM Reset to clear DTCs and adaptive memory. (REFER

to Section 2, Diagnostic Methods See: Diagnostic Trouble Code Tests and Associated Procedures\SECTION 2: Diagnostic Methods\Diagnostic Methods). COMPLETE
an Evaporative Emission Leak Check Monitor Repair Verification Drive Cycle
(REFER to Section 2, Drive Cycles See: Diagnostic Trouble Code Tests and Associated Procedures\SECTION 2: Diagnostic Methods\Drive Cycles). RERUN
Quick Test. If DTC P0455 is present, REFER to Evaporative Emissions System. Otherwise, INFORM the vehicle owner that it is important and necessary to immediately install the fuel filler cap after every refueling event.

HX65 DTC P1451: CHECK VPWR VOLTAGE TO CV SOLENOID

• Key off.
• Disconnect canister vent (CV) solenoid.
• Connect a non-powered test lamp between CV and VPWR circuits at the CV solenoid harness connector.
• Key on, engine off.
• Attempt to close and open CV solenoid driver in PCM by accessing Output Test Mode.
• Select ALL OFF mode.
• Cycle START button ON and OFF, and observe the test lamp.

Does the test lamp cycle on and off (light up and turn off)?
Yes

• KEY OFF. GO to HX66

.

No

• For test lamp always off

:

• GO to HX67

.

• For test lamp always on

:

• KEY OFF. GO to HX70

.

HX66 CHECK CV SOLENOID RESISTANCE

• Measure CV solenoid resistance.

Is resistance between 48 and 65 ohms?
Yes

• Unable to identify fault at this time. GO to Z1 See: Diagnostic Trouble Code Tests and Associated Procedures\SECTION 5: Pinpoint Tests\Z: Intermittent - Pinpoint Test

.

No

• REPLACE damaged CV solenoid. COMPLETE an EVAP system leak test

at the evaporative test port to VERIFY that a leak did not occur during component
replacement. FOLLOW the Vehicle Preparation for Monitor Repair Verification
Drive Cycle and COMPLETE an Evaporative Emission Leak Check Monitor Repair
Verification Drive Cycle (REFER to Section 2, Drive Cycles See: Diagnostic Trouble Code Tests and Associated Procedures\SECTION 2: Diagnostic Methods\Drive Cycles).

HX67 CHECK FOR OPEN VPWR CIRCUIT BETWEEN CV SOLENOID AND POWER RELAY

• Measure voltage between VPWR circuit at the CV solenoid harness connector and battery negative post.

Is voltage greater than 10.5 volts?
Yes

• KEY OFF. GO to HX68

.

No

• KEY OFF. REPAIR open circuit.

HX68 CHECK VPWR CIRCUIT FOR OPEN IN HARNESS

Note: Refer to the PCM connector pin numbers in the beginning of this pinpoint test.

• Disconnect PCM.
• Measure resistance of VPWR circuit between PCM harness connector pin (or for 150 PIN PCM, the VPWR fuse to the power relay) and CV solenoid harness connector.

Is resistance less than 5.0 ohms?
Yes

• GO to HX69

.

No

• REPAIR open circuit.

HX69 CHECK CV CIRCUIT FOR OPEN IN HARNESS

• Measure resistance of CV circuit between PCM harness connector pin and CV solenoid harness connector.

Is resistance less than 5.0 ohms?
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

• REPAIR open circuit.

HX70 CHECK CV CIRCUIT FOR SHORT TO PWR GND IN HARNESS

Note: Refer to the PCM connector pin numbers in the beginning of this pinpoint test.

• Disconnect PCM.
• Disconnect scan tool from DLC.
• Measure resistance between CV circuit at the CV solenoid harness connector and battery negative post.

Is resistance greater than 10,000 ohms?
Yes

• RECONNECT scan tool. GO to HX71

.

No

• REPAIR short circuit.

HX71 CHECK CV CIRCUIT FOR SHORT TO PWR OR CHASSIS GND IN HARNESS

• Key on, engine off.
• Measure voltage between CV circuit at the PCM harness connector and chassis ground.

Is voltage less than 1.0 volt?
Yes

• 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).

No

• KEY OFF. REPAIR short circuit to VPWR, VREF or chassis ground.

HX76 DTC P0460: CHECK FUEL TANK LEVEL

Note: For Focus, Escape, Mustang, LS6/LS8, Town Car, Windstar, Explorer/Mountaineer (150 Pin PCM), F-Series, 5.4L Lightning and Expedition/Navigator/Blackwood applications, go to Instrument Panel, Gauges and Warning Indicators, fuel level indicator or Rear Electronic Module (REM) diagnosis.

• Key on, engine off.
• Observe and record fuel gauge reading.
• Access fuel level input (FLI) PID.

Are both the fuel gauge and the FLI PID indicating between slightly above one-third (33% on FLI PID) and three quarters (75% on the FLI PID) filled?
Yes

• GO to HX78

.

No

• KEY OFF. INSPECT fuel tank for leaks. REPAIR fuel tank if necessary.

CHECK for a damaged fuse for the fuel pump (FP) to fuel gauge circuit.

• For a damaged fuse without a DTC P0460

:

• CHECK for CASE GND short to VPWR circuit. GO to B1 See: B: Electronic Engine Control (EC) Power Relay - Pinpoint Test

or GO to X1 See: X: Constant Control Relay Module (CCRM) - Pinpoint Test
(CCRM applications).

• For fuel gauge inoperative without a DTC P0460:
• REFER to Instrument Panel, Gauges and Warning Indicators.
• For DTC P0460:
• GO to HX77

.

HX77 CHECK FOR INADEQUATE FUEL LEVEL

• Key on, engine off.
• Observe both the fuel gauge and FLI PID.
• If fuel level is under one third (33% on FLI PID), add fuel (7.57 to 11.36 liters [2 to 3 gallons]) to the fuel tank.
• If fuel level is greater than three quarters (75% on FLI PID), drain (7.57 to 11.36 liters [2 to 3 gallons]) fuel from the fuel tank.

Did either the fuel gauge or FLI PID indicate a movement upward or downward as the fuel is either added or drained?
Yes

• DRIVE vehicle and RERUN Quick Test for DTCs. If DTC P0460 is

still present, GO to HX78
.

No

• KEY OFF. GO to HX79

.

HX78 CHECK FLI CIRCUIT VOLTAGE

Note: The FLI V PID must not be used for diagnosis on the 2.5L Cougar in this Pinpoint Test Step, but only applications without returnless fuel systems.
For 2.5L Cougar (without returnless fuel systems only):

• Key on, engine running.
• Measure voltage between the FLI and SIG RTN circuits at the PCM harness connector.

For All Others:

• Key on, engine running.
• Access FLI V PID.

Is voltage or FLI V PID reading between 1.23 and 2.25 volts (6.14 and 4.39 volts on 2.0L/2.5L Cougar without returnless fuel system)?
Yes

• KEY OFF.
• For Continental:
• GO to HX87

.

• For All others:
• GO to HX86

.

No

• KEY OFF. GO to HX79

.

HX79 CHECK FUEL PUMP MODULE RESISTANCE

• Disconnect fuel pump (FP) module (refer to FP module pigtail connector at the beginning of this pinpoint test).
• Measure resistance between FLI and CASE GND pins on the FP module (at pigtail).

Is resistance between 15 and 160 ohms?
Yes

• GO to HX80

.

No

• CHECK for stuck fuel level float on fuel pump (FP) module. REPAIR

as necessary. If free movement is present, REPLACE fuel pump module assembly.

HX80 CHECK FLI CIRCUIT VOLTAGE AT FP MODULE

• Disconnect the instrument cluster connector to the fuel gauge. (Refer to Instrument Panel, Gauges and Warning Indicators.)
• Key on, engine off.
• Measure voltage between FLI circuit at the FP module harness connector and battery negative post.

Is voltage greater than 5 volts?
Yes

• KEY OFF. GO to HX81

.

No

• KEY OFF. GO to HX82

.

HX81 CHECK FLI CIRCUIT FOR SHORT TO VPWR IN HARNESS

• Disconnect PCM.
• Key on, engine off.
• Measure voltage between FLI circuit at the FP module harness connector and battery negative post.

Is voltage greater than 10.5 volts?
Yes

• REPAIR short circuit.

No

• 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).

HX82 CHECK FLI CIRCUIT FOR SHORT TO PWR GND IN HARNESS

• Disconnect PCM.
• Measure resistance between FLI circuit at the PCM harness connector and battery negative post.

Is resistance greater than 10,000 ohms?
Yes

• For Continental

:

• GO to HX84

.

• For All others

:

• GO to HX83

.

No

• REPAIR short circuit.

HX83 CHECK FLI CIRCUIT FOR SHORT TO CASE GND IN HARNESS

• Measure resistance between FLI and CASE GND circuits at the PCM harness connector.

Is resistance greater than 10,000 ohms?
Yes

• GO to HX85

.

No

• REPAIR short between FLI and CASE GND circuits.

HX84 CHECK FLI CIRCUIT FOR SHORT TO CASE GND IN HARNESS ON CONTINENTAL

• Measure resistance between fuel level input Pin 4 and fuel level return Pin 28 at the virtual image instrument cluster harness connector at the fuel gauge. (Refer to the Wiring Diagrams, fuel pump module to fuel gauge.)
• Measure resistance between fuel level input Pin 4 and fuel logic ground Pin 27 at the virtual image instrument cluster harness connector at the fuel gauge. (Refer to the Wiring Diagrams, PCM to fuel gauge.)

Is each resistance greater than 10,000 ohms?
Yes

• GO to HX85

.

No

• REPAIR short between FLI and fuel level return circuits or FLI

and fuel logic ground circuits.

HX85 CHECK FLI CIRCUIT FOR OPEN IN HARNESS

• Measure resistance of FLI circuit between PCM harness connector and fuel pump (FP) module (pigtail) harness connector.
• Measure resistance of FLI circuit between PCM harness connector and the instrument cluster fuel gauge harness connector.

Is each resistance less than 10.0 ohms?
Yes

• For Continental

:

• GO to HX87

.

• For All others

:

• GO to HX86

.

No

• REPAIR open circuit.

HX86 CHECK CASE GND CIRCUIT FOR OPEN IN HARNESS

• Measure resistance of CASE GND circuit between PCM harness connector and FP module (pigtail) harness connector.
• Measure resistance between the CASE GND circuit at the PCM harness connector and the fuel gauge ground at the instrument cluster fuel gauge harness connector.

Is each resistance less than 10.0 ohms?
Yes

• REFER to Instrument Panel, Gauges and Warning Indicators

(reference: Wiring Diagrams) for fuel gauge diagnosis. REPLACE fuel
gauge or REPAIR as necessary. Then RERUN Quick Test. If DTC P0460 is still
present, 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

• REPAIR open circuit.

HX87 CHECK CASE GND CIRCUIT FOR OPEN IN HARNESS ON CONTINENTAL

• Measure resistance of CASE GND circuit between PCM harness connector Pin 25 and virtual image instrument cluster harness connector Pin 27 at the fuel gauge.
• Measure resistance between CASE GND pin at FP module (pigtail) harness connector and virtual image instrument cluster harness connector Pin 28 at the fuel gauge.

Is each resistance less than 10,000 ohms?
Yes

• REFER to Instrument Panel, Gauges and Warning Indicators

(reference: Wiring Diagrams) for fuel gauge diagnosis. REPLACE fuel
gauge or REPAIR as necessary. Then RERUN Quick Test. If DTC P0460 is still
present, 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

• REPAIR open circuit.

HX88 CHECK FUEL CAP LAMP ALWAYS ON W/O DTCS

• Disconnect PCM.
• Key on, engine off.

Is the Check Fuel Cap Indicator Lamp OFF with the PCM disconnected?
Yes

• 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).

No

• The PCM has not attempted to ground the circuit between the

Check Fuel Cap Indicator Lamp and corresponding PCM pin. This has not turned the indicator lamp ON. REFER to Instrument Panel, Gauges and Warning Indicators.

HX89 CHECK FUEL CAP LAMP ALWAYS OFF W/O DTCS

• Key off.
• Disconnect the Check Fuel Cap Indicator Lamp harness connector at the instrument cluster.
• Disconnect PCM.
• Measure resistance between PCM harness connector pin (refer to Fuel Cap Off Indicator Lamp PCM Pin Table at the beginning of this pinpoint test for correct pin number) and Check Fuel Cap circuit at the indicator lamp harness connector.

Is resistance less than 5.0 ohms?
Yes

• REFER to Instrument Panel, Gauges and Warning Indicators to diagnose instrument cluster and Check Fuel Cap Bulb. If OK, 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).
VERIFY repair by turning key to ON position (lamp will turn OFF in 3 seconds).

No

• REPAIR open circuit. VERIFY repair by turning key to ON position

(lamp will turn OFF in 3 seconds).