Opel Frontera UBS. Manual - part 307

6E–134

ENGINE DRIVEABILITY AND EMISSIONS

DTC P0122 –TP Sensor Circuit  Low Voltage

 

Step

Action

Value(s)

Yes

No

1

Was the “On-Board Diagnostic (OBD) System Check”
performed?

—

Go to 

Step 2

Go to 

OBD

System

Check

2

1. Ignition “ON,” engine “OFF.”
2. With the throttle closed, observe the “TP Sensor”

display on the Tech 2.

Is the “TP Sensor” below the specified value?

0.22 V

Go to 

Step 4

Go to 

Step 3

3

1. Ignition “ON,” engine “OFF.”
2. Review and record Tech 2 Failure Records data.
3. Operate the vehicle within Failure Records

conditions as noted.

4. Using a Tech 2, monitor the “DTC” info for DTC

P0122.

Does the Tech 2 indicate DTC P0122 failed?

—

Go to 

Step 4

Refer to

Diagnostic

Aids

4

1. Ignition “OFF.”
2. Disconnect the TP sensor electrical connector.
3. Jumper the 5 volt reference “A” circuit and the TP

signal together at the TP sensor harness connector.

4. Ignition “ON.”
Observe the “TP Sensor” display on the Tech 2.

Is the “TP Sensor” at the specified value?

5 V

Go to 

Step 10

Go to 

Step 5

5

1. Disconnect jumper.
2. Connect a test light between B+ and the TP sensor

signal circuit at the TP sensor harness connector.

Observe the “TP Sensor” display on the Tech 2.

Is the “TP Sensor” at the specified value?

5 V

Go to 

Step 6

Go to 

Step 8

6

1. Ignition “OFF.”
2. Disconnect the PCM and check the 5 volt reference

“A” circuit for an open or short to ground.

3. If the 5 volt reference “A” circuit is open or shorted to

ground, repair it as necessary.

Was the 5 volt reference “A” circuit open or shorted to
ground?

—

Verify repair

Go to 

Step 7

7

Check the 5 volt reference “A” circuit for a poor
connection at the PCM and replace the terminal if
necessary.

Did the terminal require replacement?

—

Verify repair

Go to 

Step 12

8

1. Ignition “OFF.”
2. Disconnect the PCM, and check the TP signal

circuit for an open, short to ground, or short to the
sensor ground circuit.

3. If the TP sensor signal circuit is open or shorted to

ground, repair it as necessary.

Was the TP signal circuit open or shorted to ground?

—

Verify repair

Go to 

Step 9

9

Check the TP sensor signal circuit for a poor
connection at the PCM and replace the terminal if
necessary.

Did the terminal require replacement?

—

Verify repair

Go to 

Step 12

6E–135

ENGINE DRIVEABILITY AND EMISSIONS

DTC P0122 –TP Sensor Circuit  Low Voltage

  (Cont'd)

Step

No

Yes

Value(s)

Action

10

Check the TP sensor signal circuit for a poor
connection at the TP sensor and replace the terminal if
necessary.

Did the terminal require replacement?

—

Verify repair

Go to 

Step 11

11

Replace the TP sensor.

Is the action complete?

—

Verify repair

—

12

Replace the PCM.

IMPORTANT: The replacement PCM must be
programmed.  Refer to 

UBS 98model year Immobilizer

Workshop Manual.

Is the action complete?

—

Verify repair

—

6E–136

ENGINE DRIVEABILITY AND EMISSIONS

Diagnostic Trouble Code (DTC) P0123 TP Sensor Circuit  High Voltage

D06RW028

Circuit Description

The throttle position (TP) sensor circuit provides a voltage
signal that changes relative to throttle blade angle.  The
signal voltage will vary from about 0.6 volts at closed
throttle to about 4.5 volts at wide open throttle (WOT).
The TP signal is one of the most important inputs used by
the powertrain control module (PCM) for fuel control and
many of the PCM-controlled outputs.

Conditions for Setting the DTC

D

The ignition is “ON.”

D

TP sensor signal voltage is greater than 4.88 volts for
a total of 0.78 second over a 1.5-second period.

Action Taken When the DTC Sets

D

The PCM will illuminate the malfunction indicator lamp
(MIL) the first time the fault is detected.

D

The PCM will store conditions which were present
when the DTC was set as Freeze Frame and in the
Failure Records data.

D

The PCM will use a default throttle position based on
mass air flow and RPM.

Conditions for Clearing the MIL/DTC

D

DTC P0123 can be cleared by using the Tech 2 “Clear
Info” function or by disconnecting the PCM battery
feed.

Diagnostic Aids

Check for the following conditions:

D

Check intermittent codes.

D

The TP sensor shares a 5 Volt reference with the EGR
position sensor.  Check the 5 Volt reference if these
DTCs are also set.

D

The TP sensor shares a ground with the IAT sensor
and the EGR position sensor.  Check the ground if
these other DTCs are also set.

D

Poor connection at PCM – Inspect harness connectors
for backed-out terminals, improper mating, broken
locks, improperly formed or damaged terminals, and
poor terminal-to-wire connection.

D

Damaged harness – Inspect the wiring harness for
damage.  If the harness appears to be OK, observe the
TP sensor display on the Tech 2 while moving
connectors and wiring harnesses related to the TP
sensor.  A change in the display will indicate the
location of the fault.

D

Faulty TP sensor – With the ignition key “ON,” engine
“OFF,” observe the TP sensor display on the Tech 2
while slowly depressing the accelerator to wide open
throttle.  If a voltage over 4.88 volts is seen at any point
in normal accelerator travel, replace the TP sensor.

If DTC P0123 cannot be duplicated, the information
included in the Failure Records data can be useful in
determining vehicle mileage since the DTC was last set.

Test Description

Number (s) below refer to the step number(s) on the
Diagnostic Chart.
7. Components that share the TP sensor 5 volt reference
“A” circuit include the following device:

D

EGR valve

6E–137

ENGINE DRIVEABILITY AND EMISSIONS

Disconnect the component while observing the TP
sensor display on the Tech 2.  If the reading
changes drastically when this component is

disconnected, replace the component that affected
the reading.

DTC P0123 – TP Sensor Circuit High Voltage

 

Step

Action

Value(s)

Yes

No

1

Was the “On-Board Diagnostic (OBD) System Check”
performed?

—

Go to 

Step 2

Go to 

OBD

System

Check

2

1. Ignition “ON,” engine “OFF.”
2. With the throttle closed, observe the “TP Sensor”

display on the Tech 2.

Is the “TP Sensor” above the specified value?

4.88 V

Go to 

Step 4

Go to 

Step 3

3

1. Ignition “ON,” engine “OFF.”
2. Review and record Tech 2 Failure Records data.
3. Operate the vehicle within Failure Records

conditions as noted.

4. Using a Tech 2, monitor “Specific DTC” info for DTC

P0123.

Does the Tech 2 indicate DTC P0123 failed.

—

Go to 

Step 4

Refer to

Diagnostic

Aids

4

1. Disconnect the TP sensor electrical connector.
2. Observe the “TP Sensor” display on the Tech 2.

Is the “TP Sensor” near the specified value?

0 V

Go to 

Step 5

Go to 

Step 6

5

Probe the sensor ground circuit at the TP sensor
harness connector with a test light connected to B+.

Is the test light “ON?”

—

Go to 

Step 7

Go to 

Step 10

6

1. Ignition “OFF,” disconnect the PCM.
2. Ignition “ON,” engine “OFF.”
3. Check for a short to voltage on the TP sensor signal

circuit.

4. If the TP sensor signal circuit is shorted, repair it as

necessary.

Was the TP sensor signal circuit shorted?

—

Verify repair

Go to 

Step 12

7

1. Ignition “ON.”
2. Monitor the “TP Sensor” Tech 2 display while

disconnecting each of the components that share
the 5 volt reference “A” circuit (one at a time).

3. If the “TP Sensor” Tech 2 display changes, replace

the component that caused the display to change
when disconnected.

Does disconnecting any of these components cause
the “TP Sensor” display to change?

—

Verify repair

Go to 

Step 8

8

1. Ignition “OFF,” disconnect the PCM.
2. Ignition “ON,” engine “OFF.”
3. Check for a short to B+ on the 5 volt reference “A”

circuit.

4. If the 5 volt reference “A” circuit is shorted, repair it

as necessary.

Was the 5 volt reference “A” circuit shorted?

—

Verify repair

Go to 

Step 9

9

Check for poor electrical connections at the TP sensor
and replace terminals if necessary.

Did any terminals require replacement?

—

Verify repair

Go to 

Step 11