DTC P1122 Throttle Position (TP)
Sensor Circuit Intermittent Low Voltage
The Throttle Position
(TP) sensor is a potentiometer. The TP sensor is mounted to the left side of
the throttle body. The TP sensor provides a voltage signal that
changes relative to throttle blade angle. This signal voltage is one of
the most important inputs used by the PCM. The TP sensor has a 5.0 volt
reference, a ground and a signal circuit.
TP sensor Signal voltage
should be about 0.6 volt at idle. The TP sensor
voltage should increase to above 4.0 volts at wide open throttle (WOT).
When the PCM senses a
signal voltage lower than the normal operating range of the sensor, this DTC
will set.
Conditions
for Setting the DTC
TP sensor voltage is
less than 0.2 volts for 0.3 second.
Conditions
for Setting the DTC
- TP sensor voltage is less than
0.2 volts.
- All above conditions are present for
greater than 3.5 minutes.
Action
Taken When the DTC Sets
- The PCM stores the DTC information
into memory when the diagnostic runs and fails.
- The malfunction indicator lamp (MIL)
will not illuminate.
- The PCM records the operating
conditions at the time the diagnostic fails. The PCM stores this
information in the Failure Records.
Conditions
for Clearing the DTC
- A last test failed, or current DTC,
clears when the diagnostic runs and does not fail.
- A history DTC will clear after
40 consecutive warm-up cycles, if no failures are reported by this or
any other non-emission related diagnostic.
- Use a scan tool in order to clear
the DTC.
An intermittent DTC can
be caused by electromagnetic interference (EMI). Inspect related circuits for
being too close to secondary ignition wires and the alternator.
For an intermittent,
refer to Symptoms
.
Number(s) below refer to
step numbers on the diagnostic table.
- When moving related
connectors, visually/physically inspect connectors for the following:
- Poor
mating of the connector halves or a terminal not fully seated in the
connector body (backed out).
- Improperly
formed or damaged terminals. All connector terminals in the related
circuits should be carefully reformed or replaced to insure proper
contact tension.
- Poor
terminal to wire connection. Inspect for poor crimps, crimping over wire
insulation rather than the wire.
- Dirt
or corrosion on terminals. Inspect connector seals for being there and
for being damaged.
- When moving related
wiring harnesses, visually/physically inspect wiring for the following:
- Wire
insulation that is rubbed through, causing an intermittent short.
- Wiring
broken inside the insulation.
|
Step |
Action |
Value(s) |
Yes |
No |
|
Did
you perform the Powertrain On-Board Diagnostic
(OBD) System Check? |
-- |
|||
Did
DTC P0123 fail this ignition cycle? |
-- |
Go to DTC
P0122 Throttle Position (TP) Sensor Circuit Low Voltage |
||
Does
sensor value change abruptly while a related connector is being moved? |
-- |
|||
|
Using
a scan tool, observe affected sensor value while moving related wiring
harnesses. Does sensor value change abruptly while moving related electrical
harnesses? |
-- |
|||
Does
the scan tool indicate that this diagnostic failed this ignition? |
-- |
Go to Diagnostic Aids |
||
|
Repair
the damaged connectors/terminals. Refer to Repairing
Connector Terminals in Wiring Systems. Is the action complete? |
-- |
-- |
||
|
Repair
the faulty wiring. Refer to Wiring
Repairs in Wiring Systems. Is the action complete? |
-- |
-- |
||
Is
the action complete? |
-- |
-- |
||
Does
the scan tool indicate that this test ran and passed? |
-- |
|||
|
Select
the Capture Info option and the Review Info option using the scan tool. Does
the scan tool display any DTCs that you have not diagnosed? |
-- |
Go to the applicable
DTC table |
System OK |