Test Procedure

WARNING: This page does not describe the selected car, but rather 30 other vehicles, including the 2004 Mercury Sable, 2004 Mercury Mountaineer, 2004 Mercury Monterey, 2004 Mercury Marauder, and 2004 Mercury Grand Marquis. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: Proceed to DTC testing steps listed in FAULT CODE SETTING CONDITION table of fault code setting condition.

FAULT CODE SETTING CONDITION

Fault Code

KOEO

KOER

Continuous Memory

P0068 1

DH16

P0122 1

DH12

DH11

P0123 1

DH8

P1120

DH3

P1121

DH16

P1124

DH1

P1125

DH21

⁽¹⁾

For vehicles with a Electronic Throttle Control (ECT) see FAULT CODE SETTING CONDITION

DH1 KOEO AND KOER DTC P1124: CHECK FOR ANY OTHER DTCS

CHECK for DTC P1400 or P0405 in the KOEO or KOER self-test.
CHECK KOEO and KOER DTCs:

Are DTCs P1400 or P0405 present?

Yes	No
Disregard the current Diagnostic Trouble Code (DTC) at this time. Address the next DTC. Go to POWERTRAIN DTC CHARTS & DESCRIPTIONS - CNG, FLEX-FUEL & GASOLINE for DTC charts.	KEY OFF. GO to DH2.

DH2 CHECK FOR A STUCK THROTTLE PLATE OR LINKAGE

Visually inspect the throttle linkage and throttle plate for binding or sticking.
Verify the throttle plate and linkage is at closed throttle position.

Does the throttle move freely and return to a closed throttle position?

Yes	No
The throttle plate and linkage are OK. GO to DH8.	REPAIR as necessary.

DH3 DTC P1120: CHECK THE TP CIRCUIT FOR FRAYED WIRES OR CORROSION ON THE CONNECTORS

Key OFF.
Carry out a visual inspection of the pins on the harness connector at the TP sensor for corrosion.
Carry out a visual inspection of the harness wires between the TP sensor and the PCM for insulation fraying and corrosion.

Is a fault present?

Yes	No
REPAIR as necessary.	GO to DH4.

DH4 CHECK FOR A STUCK TP SENSOR

Key ON Engine OFF.
Slowly move the throttle from the closed throttle position to the wide open throttle position and observe the TP V PID.
Access the PCM -TP V PID.

Is the voltage less than 0.49 V?

Yes	No
KEY OFF. GO to DH5.	GO to DH21.

DH5 CHECK THE VOLTAGE BETWEEN THE VREF AND SIGRTN CIRCUITS AT THE TP SENSOR VEHICLE HARNESS CONNECTOR

TP Sensor connector disconnected.
Key ON Engine OFF.
Measure the voltage between:

( + )TP Sensor Connector, Harness Side	( - )TP Sensor Connector, Harness Side
VREF	SIGRTN

Is the voltage between 4 V - 6 V?

Yes	No
KEY OFF. GO to DH6.	GO to C1.

DH6 CHECK THE TP CIRCUIT FOR AN OPEN IN THE HARNESS

NOTE: REFER to the PCM connector pin numbers in the beginning of this pinpoint test.

PCM connector disconnected.
Measure the resistance between:

( + )PCM Connector, Harness Side	( - )TP Sensor Connector, Harness Side
TP	TP

Is the resistance less than 5 ohms?

Yes	No
GO to DH7.	REPAIR open circuit.

DH7 CHECK THE TP SENSOR VOLTAGE TO THE PCM

PCM connector connected.
TP Sensor connector connected.
Start the engine and idle for 2 minutes.
Key ON Engine OFF.
Access the PCM -TP V PID.
Slowly move the throttle from the closed throttle position to the wide open throttle position and observe the TP V PID.

Is the voltage between 0.17 V - 0.49 V?

Yes	No
INSTALL a new TP sensor.	If DTC P1120 is still present, GO to DH21.

DH8 DTC P0123 OR DTC P1124: INDUCE THE OPPOSITE TP SENSOR VOLTAGE

TP Sensor connector disconnected.
Key ON Engine OFF.
Access the PCM -TP V PID.

Is the voltage less than 0.17 V?

Yes	No
GO to DH9.	KEY OFF. GO to DH10.

DH9 CHECK THE VOLTAGE BETWEEN THE VREF AND SIGRTN CIRCUITS AT THE TP SENSOR VEHICLE HARNESS CONNECTOR

Key ON Engine OFF.
Measure the voltage between:

( + )TP Sensor Connector, Harness Side	( - )TP Sensor Connector, Harness Side
VREF	SIGRTN

Is the voltage between 4 V - 6 V?

Yes	No
INSTALL a new TP sensor.	GO to C1.

DH10 CHECK THE CIRCUIT FOR A SHORT TO VREF AND VPWR IN THE HARNESS

NOTE: REFER to POWERTRAIN CONTROL MODULE (PCM) CONNECTOR for PCM connector pin numbers in the beginning of this pinpoint test.

PCM connector disconnected.
NOTE: For the 150-pin PCM and the 122-pin PCM, measure to both VREF pins.
Measure the resistance between:

( + )PCM Connector, Harness Side	( - )PCM Connector, Harness Side
VPWR	TP
VREF	TP

Are the resistances greater than 10K ohms?

Yes	No
INSTALL a new PCM. REFER to FLASH ELECTRICALLY ERASEABLE PROGRAMMABLE READ ONLY MEMORY - FLASH EEPROM .	REPAIR short circuit.

DH11 CONTINUOUS MEMORY DTC P0122: CHECK THE TP CIRCUIT FOR AN INTERMITTENT CONCERN

Key ON Engine OFF.
CLEAR the PCM DTCs.
CHECK Continuous Memory DTCs:

Is DTC P0122 present?

Yes	No
GO to DH12.	GO to PINPOINT TEST Z step 1.

DH12 KOEO AND KOER DTC P0122: CHECK THE VOLTAGE BETWEEN THE VREF AND SIGRTN CIRCUITS AT THE TP SENSOR VEHICLE HARNESS CONNECTOR

Key OFF.
TP Sensor connector disconnected.
Key ON Engine OFF.
Measure the voltage between:

( + )TP Sensor Connector, Harness Side	( - )TP Sensor Connector, Harness Side
VREF	SIGRTN

Is the voltage between 4 V - 6 V?

Yes	No
GO to DH13.	GO to C1.

DH13 CHECK THE TP CIRCUIT FOR AN OPEN IN THE HARNESS

Key OFF.
PCM connector disconnected.
Measure the resistance between:

( + )PCM Connector, Harness Side	( - )TP Sensor Connector, Harness Side
TP	TP

Is the resistance less than 5 ohms?

Yes	No
GO to DH14.	REPAIR open circuit.

DH14 CHECK THE TP CIRCUIT FOR A SHORT TO PWRGND OR SIGRTN IN THE HARNESS

Measure the resistance between:

( + )PCM Connector, Harness Side	( - )PCM Connector, Harness Side
TP	PWRGND
TP	SIGRTN

Are the resistances greater than 10K ohms?

Yes	No
GO to DH15.	REPAIR short circuit.

DH15 INDUCE THE OPPOSITE TP SENSOR VOLTAGE

PCM connector connected.
Connect a 5 amp fused jumper wire between the following:

Point A TP Sensor Connector, Harness Side	Point B TP Sensor Connector, Harness Side
VREF	TP

Key ON Engine OFF.
Access the PCM -TP V PID.

Is the voltage greater than 4.65 V?

Yes	No
INSTALL a new TP sensor.	INSTALL a new PCM. REFER to FLASH ELECTRICALLY ERASEABLE PROGRAMMABLE READ ONLY MEMORY - FLASH EEPROM .

DH16 DTC P1121 OR P0068: CHECK THE RATIONALITY OPERATION BETWEEN THE TP AND MAF SENSORS

Attempt to start engine.

Does the engine start?

Yes	No
GO to DH17.	CHECK for major leaks, cracks and openings between the MAF sensor and the throttle body. If OK, GO to A1 .

DH17 CHECK THE TP SENSOR FOR MECHANICAL OPERATION

Key ON Engine OFF.
Slowly move the throttle from the closed throttle position to the wide open throttle position and observe the TP V PID.
Access the PCM -TP V PID.

Is the voltage between 0.49 V - 4.65 V?

Yes	No
GO to DH18.	INSTALL a new TP sensor.

DH18 CHECK THE TP SENSOR SIGNAL HIGH VERSUS THE ENGINE LOAD WHILE DRIVING THE VEHICLE

Key ON Engine RUN.
Drive the vehicle, exercising the throttle and TP sensor while accessing the PIDs.
Access the PCM -TP V and PCM-LOAD PIDs.

Is the TP V PID greater than 2.44 volts and the LOAD PID less than 30%?

Yes	No
Listen for air noise around the MAF sensor and throttle body while the engine is running. If OK, INSTALL a new TP sensor. GO to PINPOINT TEST HU step 1.	GO to DH20.

DH19 VERIFY NO START

Attempt to start the engine.

Does the engine start?

Yes	No
GO to DH20.	GO to A1 .

DH20 CHECK THE TP SENSOR SIGNAL LOW VERSUS THE ENGINE LOAD WHILE DRIVING THE VEHICLE

Key ON Engine RUN.
Drive vehicle while exercising the throttle and TP sensor near higher gears (preferably overdrive) while accessing the PIDs.
Access the PCM -TP V and PCM-LOAD PIDs.

Is the TP V PID less than 0.24 volt and the LOAD PID greater than 55%?

Yes	No
If continuous memory P1121 or P0068 is present, REPLACE the MAF sensor.	Unable to identify the fault at this time.

DH21 CMDTCS P1120 OR P1125: CHECK FOR TP CIRCUIT INTERMITTENT SIGNAL

Start engine and allow to idle.
Run the throttle up to 1,500 RPM for 5 seconds.
Access the PCM -TP V PID.
Lightly tap on the TP sensor and wiggle the harness connector to simulate road shock.

Is the voltage between 0.49 V - 4.65 V?

Yes	No
KEY OFF. GO to DH22.	INSPECT the TP sensor connector. If OK, INSTALL a new TP sensor.

DH22 CHECK THE TP SENSOR HARNESS FOR INTERMITTENT OPENS OR SHORTS

Key ON Engine OFF.
Access the PCM -TP V PID.
Grasp the vehicle harness closest to the TP sensor connector.
Shake and bend a small section of the harness all the way to the dashpanel.
Wiggle, shake, and bend the harness from the dash panel to the PCM.

Is the voltage between 0.49 V - 4.65 V?

Yes	No
KEY OFF. Unable to identify the fault at this time. GO to PINPOINT TEST Z step 1.	ISOLATE the fault and REPAIR as necessary.

DH23 DTC P0121: CHECK FOR OBSTRUCTION OR STICKING CONCERNS

Disconnect the accelerator cable and speed control cable from the throttle body linkage.
CAUTION: Do not attempt to clean the throttle bore and plate area. Cleaning will damage the throttle body assembly.

NOTE: Conditions of sticking or obstruction can either be within the cables or throttle body assembly.
Rotate the throttle body linkage.

Does the throttle body rotate freely without a sticking, binding or grabbing condition?

Yes	No
INSPECT the cable(s). REPAIR as necessary. RERUN the Quick Test. If DTC P0121 is still present, GO to DH24.	REPLACE the throttle body assembly.

DH24 CHECK THE FUNCTIONALITY OF THE THROTTLE POSITION SENSOR

Key ON Engine OFF.
While slowly pressing the accelerator from the closed throttle position to the wide open throttle position, observe the TP V PID.

Did the TP V PID display a smooth reading during accelerator movement?

Yes	No
VERIFY a symptom no longer exists.	KEY OFF. INSTALL a new TP sensor.