Opel Frontera UBS. Manual - part 2439

 

  Index      Opel     Opel Frontera UBS - service repair manual 1998-2002 year

 

Search            

 

 

 

 

 

 

 

 

 

Content   ..  2437  2438  2439  2440   ..

 

 

Opel Frontera UBS. Manual - part 2439

 

 

6E–70

4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS

Diagnostic Trouble Code (DTC) P0121 (Flash DTC 33) 

AP Sensor Rationality

060RW134

Circuit Description

The accel position (AP) sensor circuit provides a voltage
signal that changes relative to throttle blade angle.
The AP signal is one of the most important inputs used by
the Engine Control Module ECM for fuel volume control
and many of the ECM-controlled outputs. If the ECM
detects an out-of-range condition, DTC P0121 will set.

Action Taken When the DTC Sets

D

The ECM will illuminate the malfunction indicator lamp
(MIL) after fault is detected.

D

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

Conditions for Clearing the MIL/DTC

D

DTC P0121 can be cleared by using the Tech 2 “Clear
info ” function or by disconnecting the ECM battery
feed.

Diagnostic Aids

Check for the following conditions:

D

Poor connection at ECM – 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
ECT display on the Tech 2 while moving connectors
and wiring harnesses related to the sensor.  A change
in the display will indicate the location of the fault.

If DTC P0121 cannot be duplicated, the information
included in the Failure Records data can be useful in
determining vehicle mileage since the DTC was last set.

6E–71

4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS

DTC P0121 –AP Sensor Rationality

 

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

Check the Idle SW.

Was the Idle SW circuit open or darmage?

Replace the

Idle SW

circuit

Go to 

Step 3

3

Observe the AP angle reading on the Tech 2 while
slowly opening the throttle.

Does the AP angle increase steadily and evenly from
the closed throttle value to the wide open throttle
value?

Closed

throttle = 0%

Wide open

throttle =

100%

Refer to

Diagnostic

Aids

Go to 

Step 4

4

1. Disconnect the AP sensor.
2. Observe the AP sensor reading on the Tech 2.

Is the AP sensor reading near the specified value?

0 V

Go to 

Step 5

Go to 

Step 6

5

1. Connect a test light between the 5 volt reference

“J2” circuit and the AP sensor signal circuit at the AP
sensor harness connector.

2. Observe the AP sensor reading on the Tech 2.

Is the AP sensor reading at the specified value?

5 V

Go to 

Step 8

Go to 

Step 7

6

Check the following items:

1. AP signal circuit for a short to voltage.
2. AP sensor ground circuit for high resistance

between the ECM and the AP sensor.

3. AP sensor ground circuit for a poor connection.
4. If a problem is found, repair wiring harness as

necessary.

Was a problem found?

Verify repair

Go to 

Step 9

7

Check the following items:

1. AP signal circuit or 5 volt reference “J2” circuit for a

poor connection.

2. AP signal circuit or 5 volt reference “J2” circuit for

high resistance between the ECM and the AP
sensor.

3. If a problem is found, repair wiring harness as

necessary.

Was a problem found?

Verify repair

Go to 

Step 9

8

Replace the AP sensor.

Is the action complete?

Verify repair

9

Replace the ECM (Refer to the Data Programming in
Case of ECM change).

Is the action complete?

Verify repair

6E–72

4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS

Diagnostic Trouble Code (DTC) P0122 (Flash DTC 21) 

AP Sensor Low Voltage

060RW134

Circuit Description

The accelerator position (AP) sensor circuit provides a
voltage signal that changes relative to throttle blade
angle.
The AP signal is used by the Engine Control Module ECM
for fuel volume control and many of the ECM-controlled
outputs.

Action Taken When the DTC Sets

D

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

Conditions for Clearing the MIL/DTC

D

DTC P0122 can be cleared by using the Tech 2 “Clear
Info” function or by disconnecting the ECM battery
feed.

Diagnostic Aids

Check for the following conditions:

D

Poor connection at ECM – 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
throttle position 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.

If DTC P0122 cannot be duplicated, the information
included in the Failure Records data can be useful in
determining vehicle mileage since the DTC was last set.

DTC P0122 –AP Sensor 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

Check the AP sensor signal circuit.

Was the AP sensor signal circuit open or darmage?

Replace the

APS circuit

Go to 

Step 3

6E–73

4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS

DTC P0122 –AP Sensor Low Voltage

  (Cont'd)

Step

No

Yes

Value(s)

Action

3

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

display on the Tech 2.

Is the “AP Sensor” below the specified value?

0.1 V

Go to 

Step 5

Go to 

Step 4

4

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 5

Refer to

Diagnostic

Aids

5

1. Ignition “OFF.”
2. Disconnect the AP sensor electrical connector.
3. Jumper the 5 volt reference “J2” circuit and the AP

signal together at the AP sensor harness connector.

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

Is the “AP Sensor” at the specified value?

5 V

Go to 

Step 11

Go to 

Step 6

6

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

signal circuit at the AP sensor harness connector.

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

Is the “AP Sensor” at the specified value?

5 V

Go to 

Step 7

Go to 

Step 9

7

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

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

3. If the 5 volt reference “J2” circuit is open or shorted

to ground, repair it as necessary.

Was the 5 volt reference “J2” circuit open or shorted to
ground?

Verify repair

Go to 

Step 8

8

Check the 5 volt reference “J2” circuit for a poor
connection at the ECM and replace the terminal if
necessary.

Did the terminal require replacement?

Verify repair

Go to 

Step 13

9

1. Ignition “OFF.”
2. Disconnect the ECM, and check the AP signal

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

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

ground, repair it as necessary.

Was the AP signal circuit open or shorted to ground?

Verify repair

Go to 

Step 10

10

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

Did the terminal require replacement?

Verify repair

Go to 

Step 13

11

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

Did the terminal require replacement?

Verify repair

Go to 

Step 12

 

 

 

 

 

 

 

Content   ..  2437  2438  2439  2440   ..