Ford F150 Pickup. Instruction — part 1489

Fig. 216: Throttle Position Sensor Voltage
Courtesy of FORD MOTOR CO.

Diagnostic Aids

Perform this test only when directed here. This system test is intended to diagnose the following:

z

ETC Throttle Position (TP) sensor.

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ETC throttle body control motor.

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ETC throttle body assembly.

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Harness Circuits: TP1, TP2, ETCREF, ETCRTN.

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Powertrain Control Module (PCM).

2003 Ford Pickup F150

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

Fig. 217: Identifying ETC Motor Circuits & Connector Terminals
Courtesy of FORD MOTOR CO.

For TP sensor circuit and connector terminals, see Fig. 164.

Testing

1) For KOEO, KOER & Continuous Memory DTCs P0121, P0221, P2104, P2105, P2106 , P2111 &
P2112: Check For Throttle Plate Binding Or Obstruction
For DTC P0121, P2111 and P2112, fault exhibits a symptom of limited power. A TP V PID reading less
than 13 percent (.65 volt), or greater than 93 percent (4.65 volts) in KOEO, continuous memory or KOER
indicates a hard fault. Possible causes for this fault are:

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Binding throttle linkage.

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Damaged throttle body.

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TP circuit open to PCM.

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Damaged TP sensor.

NOTE:

Always service Accelerator Pedal Position (APP) sensor DTCs first, then
proceed to Throttle Position (TP) sensor and TACM motor DTCs that may be
present. This is necessary because the ETC system DTCs effect each other. It
should also be noted, that a KOER DTC P0121 can be set by the operator
resting a foot on the accelerator pedal during the test.

NOTE:

For additional testing information, see DIAGNOSTIC AIDS.

2003 Ford Pickup F150

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

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SIG RTN circuit open to TP sensor.

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Operator placing.

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PCM damaged.

For DTCs P2104, P2105 and P2106, throttle actuator control system is in FMEM mode. Possible causes
for this fault are:

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Unplugged motor, circuits shorted to power.

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TACM motor open.

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TACM motor stuck open or closed.

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PCM damaged.

The following steps should be taken in order due to the nature of the Electronic Throttle Control system:

A. These DTCs effect system operation and must be repaired first: P0102, P0103, P0122, P0123,

P0222, P0223, P0320, P0715, P0720, P0500 and P2135. See DIAGNOSTIC TROUBLE CODE
DEFINITIONS.

B. These DTCs must be repaired next due to the nature of the system: P2121, P2122, P2123, P2126,

P2127, P2128, P2131, P2132 and P2133. Go to TEST DK, step 2).

C. If DTCs P2111 or P2112 are present, continue with this step.

D. If DTC U0300 is present, see appropriate BODY CONTROL MODULES article.

If should also be noted that a KOER DTC P0121 can be set by the operator resting a foot on the
accelerator pedal during the test.

Turn ignition switch to OFF position. Visually inspect the throttle plate for binding or sticking. Remove
air inlet from the throttle body. Slowly push the throttle plate open and release, then push closed
completely. Does the throttle plate open and close fully, without sticking? If yes, go to next step. If DTC
P2100 is present, go to step 22). If DTC P2101 is present, go to step 25). If DTC P2107 is present, go to
step 23). If no, repair or replace throttle body as necessary.

2) For KOEO, KOER & Continuous Memory DTC P0122: Check TP1 & TP2 Closed & Open
Voltage Ranges
Fault exhibits a symptom of limited power. A TP1 PID (TP V PID) reading less than 3.42 percent (0.17
volt) in KOEO, continuous memory or KOER, indicates a hard fault. Possible causes of this fault are:

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Open ETC TP sensor harness.

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Short to ground in ETC TP sensor harness.

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Damaged TP sensor.

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SIG RTN circuit open to TP sensor.

Turn ignition switch to ON position, with engine off. Access TP 1 and TP 2 PIDS. Depress accelerator
pedal slowly to the floor and release. Are the TP sensor signals within the following chart ranges? See
ETC TP SENSOR VOLTAGE RANGES table. If yes, go to step 9). If no, for DTCs P0121, P0122,

NOTE:

For additional testing information, see DIAGNOSTIC AIDS.

2003 Ford Pickup F150

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

P0221, P0222 and P2106 together, go to next step. For P0121, P2106 and 2135, and/or P0221, P0222,
P2106 and P2135, go to step 4). For DTCs P0121, P0122, P2106 and P2135, and/or P0221, P0223, P2106
and P2135, go to step 5). For DTCs P0121, P0123, P2106 and P2135, or P0221, P0223, P2106 and
P2135, go to step 6).

ETC TP SENSOR VOLTAGE RANGES

3) Check For Proper ETCREF Voltage

Disconnect ETC TP harness connector. Turn ignition switch to ON position. Measure voltage between
ETCREF and ETCRTN pins at the ETC TP sensor harness connector. See Fig. 164. Is the voltage
between 4.0 and 6.0 volts? If yes, go to next step. For P0122, go to step 4). If no, go to TEST C, step 1).

4) For KOEO, KOER & Continuous Memory DTC P0223 & P2135: Check TP Sensor Harness For
Open Circuit
PCM flagged a fault indicating that TP1 and TP2 disagree, or that TP1 should not be in it's present
position given the position of TP2 unless a problem is present. Possible causes for this fault are:

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ETC TP is defective.

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TP sensor shorted internally to VREF.

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TP sensor harness is shorted to power.

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TP sensor signal wire are shorted together.

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Damaged PCM.

For DTCs P0122, P2106 and P2135, check TP1 circuit only, for DTCs P0221, P0222, P2106 and P2135,
check TP2 circuit only. Turn ignition switch to OFF position, remove PCM harness connector. Measure
resistance between the PCM and TP sensor harness connectors for the TP1 circuit. Measure resistance
between the PCM and TP sensor harness connectors for the TP2 circuit. Are both resistances less than 5
ohms? If yes, go to next step. If no, repair open circuit.

5) For KOEO, KOER & Continuous Memory DTC P0222: Check TP Sensor Harness For Short To
GND

For DTCs P0121, P0122, P2106 and P2135, check TP1 circuit only, for DTCs P0221, P0222, P2106 and
P2135, check TP2 circuit only. Measure resistance between the TP1 circuit, and battery ground from the
TP sensor harness connector. Measure resistance between the TP2 circuit, and battery ground from the TP
sensor harness connector. Are both resistances greater than 10 k/ohms? If yes, go to next step. If no,
repair short circuit.

6) Check TP Sensor Circuits For Shorts To ETCRTN

Accelerator Pedal Position

TP 1 (Volts)

TP 2 (Volts)

Closed Throttle

4.0-4.4

0.9-1.5

Wide Open Throttle

0.9-1.5

3.5-5.5

NOTE:

For additional testing information, see DIAGNOSTIC AIDS.

2003 Ford Pickup F150

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