Acceleration Control - 1.3L Duratec-8V
(Rocam)llI25L Duratec-1 6V (Sigma)llI4L
31 0-02A-4 Duratec-1 6V (Sigma)/l .6L
Duratec-1 6V (Sigma)
31 0-02A-4
DIAGNOSIS AND TESTING
Electronic Throttle Body
The electronic throttle body is similar to a
mechanical throttle body used on a cable
accelerator system. Instead of the cable moving
the throttle plate open and closed, it uses an
internal electrical motor that is driven by the PCM.
The electronic throttle body has two sensors that
measure the throttle plate position. The sensors
output a voltage to the PCM corresponding to the
plate position.
When the electronic throttle body motor is not in
use, the throttle plate sits slightly open in a default
position (not idle position). This position is
maintained by two internal springs. One acts
upwards and one downwards. Screws on the
electronic throttle body will not adjust the idle
speed, the idle speed is controlled by the PCM.
PCM
The PCM reads the voltage from the pedal and
converts this signal into a driver request. The driver
request is realized by opening or closing the throttle
body. To do this, the PCM increases or decreases
power to the electronic throttle body motor. The
PCM then checks the signal from the electronic
throttle body throttle position (TP) sensor, to make
sure that the requested position has been
achieved. The PCM also monitors all the sensors
to make sure that the system is functioning as
expected. All electronic accelerator control system
faults will be detected by the PCM and set a
diagnostic trouble code (DTC) which triggers the
electronic accelerator control fail message
accordingly. For safety reasons, some faults will
also reduce the vehicle performance.
Diagnostic Trouble Codes
Description
When a component electrical error is set it means
that the PCM is not receiving the expected signal.
This means that the concern may lie between the
component and the PCM. All wiring and electrical
connectors should be checked before a new
component is installed. Also note that general
vehicle electrical issues can have an effect on other
systems. Battery voltage and relay concerns should
be rectified first.
Accelerator Pedal Codes
These are the DTCs relating to the pedal circuit.
They do not imply necessarily that the accelerator
pedal is at fault, but it will in any case relate to area
"A (see system overview).
P2120 - Accelerator pedal sensor 1 electrical
error
P2122 - Accelerator pedal sensor I electrical
error short to ground or open circuit
P2123 - Accelerator pedal sensor I electrical
error short to battery
P2125 - Accelerator pedal sensor 2 electrical
error
P2127 - Accelerator pedal sensor 2 electrical
error short to ground or open circuit
P2128 - Accelerator pedal sensor 2 electrical
error short to battery
P2138 - Accelerator pedal sensor 1 & 2 ratio
error
Electronic Throttle Body Circuit Codes
These are the DTCs relating to the electronic
throttle body circuit. They do not imply necessarily
( ,)
that the electronic throttle body is the concern, but
it will in any case relate to area "B" (see system
overview).
PO1 20 - Throttle position (TP) sensor 1
electrical error
PO122 - (TP) sensor 1 electrical error short to
ground
PO123 - (TP) sensor 1 electrical error short to
battery or line break
PO220 - (TP) sensor 2 electrical error
PO222 - (TP) sensor 2 electrical error short to
ground or open circuit
PO223 - (TP) sensor 2 electrical error short to
battery
P2135 - (TP) sensor ratio error
P21
I 9 - Throttle plate convergence error
- This is when the throttle plate has not moved
to the requested position in the required time.
This could be caused by the following:
- The electronic throttle body motor is not
receiving the necessary voltage. Check the
--
electronic throttle body motor wiring. The ( PCM is not receiving the correct throttle plate '
position signal from the electronic throttle
body. Check the TP sensor wiring from the
2006.0 Fiesta 1212006 G356253en
procarmanuals.com
Acceleration Control - I .3L Duratec-8V
(Rocam)llI25L Duratec-I 6V (Sigma)llI4L
31 0-02A-6 Duratec-I 6V (Sigma)/l .6L Duratec-1 6V (Sigma)
31 0-02A-6
DIAGNOSIS AND TESTING
PO653 - Sensor voltage supply circuit 2 short Inspection and Verification
to battery
- Check the power supply to the PCM (battery 1. Verify the customer concern.
voltage, relays, wiring harness and electrical 2. Visually inspect for obvious signs of mechanical
connectors as well as fuses). If no concern
or electrical damage.
- Follow WDS instructions. I - Accelerator pedal I Fuse(s) I
- is found, install a new PCM.
PI 71 2 - Electronic gear shift torque demand is Visual
Inspection Chart
N0TE:lf the vehicle is in a limited performance
mode, a system related DTC and the electronic
accelerator control fail light message will illuminate.
If there is a performance issue without these items
the electronic accelerator control system is running
correctly but another issue may exist elsewhere
on the vehicle.
not
a plausible signal (ASM only) - Linkage
- Accelerator cable
- Throttle body
Relay(s)
Wiring harness
Electrical
connector(s)
Accelerator pedal
Throttle body
Mechanical
Electrical
Symptom Chart < .I
Be
aware that installing new system related
components without these
DTCs will not improve
Symptom Chart
- Vehicles With 1.3L Engine
Symptom Possible Sources
Powertrain control
module (PCM)
Action
the
vehicle behavior for general issues such as:
high fuel consumption 3.
If an obvious cause for an observed or reported
concern is found, correct the cause (if possible)
poor idle quality before proceeding to the next step.
poor or no engine start
4. If the cause is not visually evident, verify the
symptom and refer to Symptom Chart.
f
Accelerator pedal is hard to
depress or has a
roughlraspy
or sticky feel
Damaged accelerator cable.
REFER to: Throttle Body (303-
04A, Removal and Installa-
tion).
INSTALL a new accelerator
cable.
Accelerator cable incorrectly installed.
Worn or damaged throttle body.
I Accelerator pedal does not I Weak or broken throttle body I INSTALL a new throttle body. I
CHECK the accelerator cable
for correct installation.
INSTALL a new throttle body.
return freely REFER to: Throttle Body (303-
04A, Removal and Installa-
tion).
I Worn or damaged throttle body. I INSTALL a new throttle body. I
I I I REFER to: Throttle Body (303- 1 04A, Removal and Installa-
tion).
High engine idle speed Damaged accelerator cable. INSTALL a new accelerator
I cable.
2006.0 Fiesta 1212006 G356253en
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