Opel Frontera UBS. Manual - part 290

6E–66

ENGINE DRIVEABILITY AND EMISSIONS

D

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

D

Damaged harness. Inspect the wiring harness for
damage.  If the harness is not damaged, observe an
affected sensor’s displayed value on the Tech 2 with
the ignition “ON” and the engine “OFF” while you move
the connectors and the wiring harnesses related to the
following sensors:

D

IAT

D

ECT

D

TP

D

MAP

D

EGR

D

TFT

Multiple PCM Information Sensor DTCs Set

 

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. Turn the ignition “OFF,” disconnect the PCM.
2. Turn the ignition “ON,” check the 5 volt reference A

circuit for the following conditions:

D

A poor connection at the PCM.

D

An open between the PCM connector and the
splice.

D

A short to ground.

D

A short to voltage.

Is there an open or short?

—

Go to 

Step 3

Go to 

Step 4

3

Repair the open or short.

Is the action complete?

—

Verify repair

—

4

Check the sensor ground circuit for the following
conditions:

D

A poor connection at the PCM or the affected
sensors.

D

An open between the PCM connector and the
affected sensors.

Is there an open or a poor connection?

—

Go to 

Step 5

Go to 

Step 6

5

Repair the open or the poor connection.

Is the action complete?

—

Verify repair

—

6

Measure the voltage between the EGR pintle position
sensor signal circuit at the PCM harness connector and
ground.

Does the voltage measure near the specified value?

0 V

Go to 

Step 7

Go to 

Step 12

7

Measure the voltage between the MAP sensor signal
circuit at the PCM harness connector and ground.

Does the voltage measure near the specified value?

0 V

Go to 

Step 8

Go to 

Step 15

8

Measure the voltage between the TP sensor signal
circuit at the PCM harness connector and ground.

Does the voltage measure near the specified value?

0 V

Go to 

Step 9

Go to 

Step 16

9

Measure the voltage between the IAT sensor signal
circuit at the PCM harness connector and ground.

Does the voltage measure near the specified value?

0 V

Go to 

Step 10

Go to 

Step 17

10

Measure the voltage between the ECT sensor signal
circuit at the PCM harness connector and ground.

Does the voltage measure near the specified value?

0 V

Go to 

Step 11

Go to 

Step 18

6E–67

ENGINE DRIVEABILITY AND EMISSIONS

Multiple PCM Information Sensor DTCs Set

  (Cont'd)

Step

No

Yes

Value(s)

Action

11

1. Disconnect the EGR valve.
2. Measure the voltage between the EGR pintle

position sensor signal circuit at the PCM harness
connector and ground.

Does the voltage measure near the specified value?

0 V

Go to 

Step 13

Go to 

Step 18

12

Measure the voltage between the TFT sensor signal
circuit at the PCM harness connector and ground.

Does the voltage measure near the specified value?

0 V

Go to 

Step 20

Go to 

Step 19

13

Replace the EGR valve.

Is the action complete?

—

Verify repair

—

14

Locate and repair the short to voltage in the MAP
sensor signal circuit.

Is the action complete?

—

Verify repair

—

15

Locate and repair the short to voltage in the TP sensor
signal circuit.

Is the action complete?

—

Verify repair

—

16

Locate and repair the short to voltage in the IAT sensor
signal circuit.

Is the action complete?

—

Verify repair

—

17

Locate and repair the short to voltage in the ECT
sensor signal circuit.

Is the action complete?

—

Verify repair

—

18

Locate and repair the short to voltage in the EGR pintle
position sensor signal circuit.

Is the action complete?

—

Verify repair

—

19

Locate and repair the short to voltage in the TFT sensor
signal circuit.

Is the action complete?

—

Verify repair

—

20

Replace the PCM.

IMPORTANT: The replacement PCM must be
programmed.  Refer to 

UBS 98model year Immobilizer

Workshop Manual.

Is the action complete?

—

Go to 

OBD

System

Check

—

6E–68

ENGINE DRIVEABILITY AND EMISSIONS

Exhaust Gas Recirculation (EGR)

Diagnosis (For except EXPORT and

SOUTH AFRICA)

Pintle position error diagnosis is covered by DTC P0402,
P0404, P1404, P0405, P0406. If EGR diagnostic trouble
codes P0402, P0404, P1404, P0405, P0406 are
encountered, refer to the DTC charts.

Engine Tech 2 Data Definitions and

Ranges

A/C CLUTCH – Tech 2 Displays ON or OFF –
Indicates whether the PCM has commanded the A/C
clutch ON.  Used in A/C system diagnostic.

A/C REQUEST — Tech 2 Displays YES or NO —
Indicates the state of the A/C request input circuit from the
HVAC controls.  The PCM uses the A/C request signal to
determine whether A/C compressor operation is being
requested.

AIR/FUEL RATIO — Tech 2 Range 0.0-25.5 —
Air/fuel ratio indicates the PCM commanded value.  In
closed loop, the air/fuel ratio should normally be
displayed around “14.2-14.7.”  A lower air/fuel ratio
indicates a richer commanded mixture, which may be
seen during power enrichment or TWC protection modes.
A higher air/fuel ratio indicates a leaner commanded
mixture.  This can be seen during deceleration fuel mode.

BAROMETRIC PRESSURE — Tech 2 Range 10-105
kPa/0.00-5.00 Volts —
The barometric pressure reading is determined from the
MAP sensor signal monitored during key up and wide
open throttle (WOT) conditions.  The barometric pressure
is used to compensate for altitude differences and is
normally displayed around “61-104” depending on
altitude and barometric pressure.

CHECK TRANS LAMP — AUTO TRANSMISSION —
Indicates the need to check for a DTC with the Tech 2
when the lamp is flashing 0.2 seconds ON and 0.2
seconds OFF.

CMP ACT. COUNTER – Cam Position Activity
DECEL FUEL MODE — Tech 2 Display ACTIVE or
INACTIVE —
“ACTIVE” displayed indicates that the PCM has detected
conditions appropriate to operate in deceleration fuel
mode.  The PCM will command the deceleration fuel
mode when it detects a closed throttle position while the
vehicle is traveling over 20 mph.  While in the deceleration
fuel delivered by entering open loop and decreasing the
injector pulse width.

DESIRED EGR POS. — Tech 2 Range 0%-100% —
Represents the EGR pintle position that the PCM is
commanding.

DESIRED IDLE — Tech 2 Range 0-3187 RPM —
The idle speed that the PCM is commanding.  The PCM
will compensate for various engine loads based on engine
coolant temperature,  to keep the engine at the desired
speed.

ECT — (Engine Coolant Temperature) Tech 2
Range –40

°

C to 151

°

C (–40

°

F to 304

°

F) —

The engine coolant temperature (ECT) is mounted in the
coolant stream and sends engine temperature
information to the PCM.  The PCM applies 5 volts to the
ECT sensor circuit.  The sensor is a thermistor which
changes internal resistance as temperature changes.
When the sensor is cold (high resistance), the PCM
monitors a high signal voltage and interprets that as a cold
engine.  As the sensor warms (decreasing resistance),
the voltage signal will decrease and the PCM will interpret
the lower voltage as a warm engine.

EGR DUTY CYCLE — Tech 2 Range 0%-100% —
Represents the EGR valve driver PWM signal from the
PCM.  A duty cycle of 0% indicates that no EGR flow is
being commanded; a 100% duty cycle indicates
maximum EGR flow commanded.

EGR FEEDBACK — Tech 2 Range 0.00-5.00 Volts —
Indicates the EGR pintle position sensor signal voltage
being monitored by the PCM.  A low voltage indicates a
fully extended pintle (closed valve); a voltage near 5 volts
indicates a retracted pintle (open valve).

ENGINE LOAD — Tech 2 Range 0%-100% —
Engine load is calculated by the PCM from engine speed
and MAF sensor readings.  Engine load should increase
with an increase in RPM or air flow.

ENGINE RUN TIME — Tech 2 Range
00:00:00-99:99:99 Hrs:Min:Sec —
Indicates the time elapsed since the engine was started.
If the engine is stopped, engine run time will be reset to
00:00:00.

ENGINE SPEED — Range 0-9999 RPM —
Engine speed is computed by the PCM from the 58X
reference input.  It should remain close to desired idle
under various engine loads with engine idling.

FUEL PUMP — Tech 2 Displays ON or OFF —
Indicates the PCM commanded state of the fuel pump
relay driver circuit.

FUEL TRIM CELL — Tech 2 Range 0-21 —
The fuel trim cell is dependent upon engine speed and
MAF sensor readings.  A plot of RPM vs.  MAF is divided
into 22 cells. Fuel trim cell indicates which cell is currently
active.

FUEL TRIM LEARN — Tech 2 Displays NO or YES
—
When conditions are appropriate for enabling long term
fuel trim corrections, fuel trim learn will display “YES.”
This indicates that the long term fuel trim is responding to
the short term fuel trim.  If the fuel trim learn displays
“NO,” then long term fuel trim will not respond to changes
in short term fuel trim.

HO2S BANK 1, SEN. 1 — Tech 2 Range 0-1132 mV
—
 Represents the fuel control exhaust oxygen sensor
output voltage.  Should fluctuate constantly within a range
between 10 mV (lean exhaust) and 1000 mV (rich
exhaust) while operating in closed loop.

6E–69

ENGINE DRIVEABILITY AND EMISSIONS

HO2S BANK2, SEN. 1—Tech 2 Range 0-1132 mV—
Represents the fuel control exhaust oxygen sensor
output voltage.  Should fluctuate constantly within a range
between 10mV (lean exhaust) and 1000 mV (rich
exhaust) while operating in closed loop.

HO2S BANK 1, SEN. 1—Tech 2 Displays NOT
READY or READY—
Indicates the status of the exhaust oxygen sensor.  The
Tech 2 will indicate that the exhaust oxygen sensor is
ready when the PCM detects a fluctuating HO2S voltage
sufficient to allow closed loop operation.  This will not
occur unless the exhaust oxygen sensor is warmed up.

HO2S BANK 2, SEN. 1 — Tech 2 Displays NOT
READY or READY —
Indicates the status of the exhaust oxygen sensor.  The
Tech 2 will indicate that the exhaust oxygen sensor is
ready when the PCM detects a fluctuating HO2S voltage
sufficient to allow closed loop operation.  This will not
occur unless the exhaust oxygen sensor is warmed up.

HO2S WARM UP TIME BANK 1, SEN. 1/BANK 2
SEN. 1 — Tech 2 Range 00:00:00-99:99:99
HRS:MIN:SEC —
Indicates warm-up time for each HO2S.  The HO2S
warm-up time is used for the HO2S heater test.  The PCM
will run the heater test only after a cold start (determined
by engine coolant and intake air temperature at the time
of start-up) and only once during an ignition cycle.  When
the engine is started the PCM will monitor the HO2S
voltage.  When the HO2S voltage indicates a sufficiently
active sensor, the PCM looks at how much time has
elapsed since start-up.  If the PCM determines that too
much time was required for the HO2S to become active,
a DTC will set.  If the engine was warm when started,
HO2S warm-up will the display “00:00:00”.

IAC POSITION — Tech 2 Range 0-255 Counts —
Displays the commanded position of the idle air control
pintle in counts.  A larger number of counts means that
more air is being commanded through the idle air
passage.  Idle air control should respond fairly quickly to
changes in engine load to maintain desired idle RPM.

IAT (INTAKE AIR TEMPERATURE) — Tech 2 Range
–40

°

C to 151

°

C (–40

°

F to 304

°

F) —

The PCM converts the resistance of the intake air
temperature sensor to degrees.  Intake air temperature
(IAT) is used by the PCM to adjust fuel delivery and spark
timing according to incoming air density.

IGNITION 1 — Tech 2 Range 0-25.5 Volts —
This represents the system voltage measured by the
PCM at its ignition feed.

INJ. PULSE BANK 1/INJ. PULSE BANK 2 — Tech 2
Range 0-1000 msec. —
Indicates the amount of time the PCM is commanding
each injector “ON” during each engine cycle.  A longer
injector pulse width will cause more fuel to be delivered.
Injector pulse width should increase with increased
engine load.

KS NOISE CHANNEL (Knock Sensor) —
Indicates the output from the KS noise channel.  There is
always some electrical noise in an engine compartment
and to avoid mistaking this as engine knock, the output
from the knock sensor is compared to the output from the
noise channel.  A knock condition is not set unless the
knock sensor output is greater than the noise channel
output.

LONG TERM FUEL TRIM BANK 1/BANK 2 —
The long term fuel trim is derived from the short term fuel
trim values and represents a long term correction of fuel
delivery for the bank in question.  A value of 0% indicates
that fuel delivery requires no compensation to maintain
the PCM commanded air/fuel ratio.  A negative value
significantly below 0% indicates that the fuel system is
rich and fuel delivery is being reduced (decreased injector
pulse width).  A positive value significantly greater than
0% indicates that a lean condition exists and the PCM is
compensating by adding fuel (increased injector pulse
width).  Because long term fuel trim tends to follow short
term fuel trim, a value in the negative range due to
canister purge at idle should not be considered unusual.
Fuel trim values at maximum authority may indicate an
excessively rich or lean system.

LOOP STATUS — Tech 2 Displays OPEN or
CLOSED —
“CLOSED” indicates that the PCM is controlling fuel
delivery according to oxygen sensor voltage.  In “OPEN”
the PCM ignores the oxygen sensor voltage and bases
the amount of fuel to be delivered on TP sensor, engine
coolant, and MAF sensor inputs only.

MAF — Tech 2 Range 0.0-512 gm/s —
MAF (mass air flow) is the MAF input frequency
converted to grams of air per second. This indicates the
amount of air entering the engine.

MAP — Tech 2 Range 10-105 kPa (0.00-4.97 Volts)
—
The manifold absolute pressure (MAP) sensor measures
the change in the intake manifold pressure from engine
load, EGR flow, and speed changes.  As intake manifold
pressure increases, intake vacuum decreases, resulting
in a higher MAP sensor voltage and kPa reading.  The
MAP sensor signal is used to monitor intake manifold
pressure changes during the EGR flow test, to update the
BARO reading, and as an enabling factor for several of
the diagnostics.

MIL — Tech 2 Displays ON or OFF —
Indicates the PCM commanded state of the malfunction
indicator lamp.

POWER ENRICHMENT — Tech 2 Displays ACTIVE
or INACTIVE —
“ACTIVE” displayed indicates that the PCM has detected
conditions appropriate to operate in power enrichment
mode.  The PCM will command power enrichment mode
when a large increase in throttle position and load is
detected. While in power enrichment mode, the PCM will
increase the amount of fuel delivered by entering open
loop and increasing the injector pulse width.  This is done
to prevent a possible sag or hesitation from occurring
during acceleration.