Opel Frontera UBS. Manual - part 2168

6E–245

ENGINE DRIVEABILITY AND EMISSIONS

Diagnostic Trouble Code (DTC) P1171 Fuel System Lean During Acceleration

060RW193–1

Circuit Description

The powertrain control module (PCM) internal circuitry
can identify if the vehicle fuel system is capable of
supplying adequate amounts of fuel during heavy
acceleration (power enrichment).  The PCM monitors the
voltage of the oxygen sensor during power enrichment.
When a power enrichment mode of operation is
requested during “closed loop” operation (by heavy
acceleration), the PCM will provide more fuel to the
engine.  Under these conditions the PCM should detect a
“rich”  condition (high oxygen sensor voltage).  If this “rich”
exhaust is not detected at this time, a DTC P1171 will set.
A plugged fuel filter, restricted fuel line, restricted in-tank
filter or defective fuel pump can prevent adequate
amounts of fuel from being supplied during power
enrichment mode.

Conditions for Setting the DTC

D

No related DTCs.

D

Engine is operating in “closed loop power enrichment”
mode for 3 seconds.

D

Engine coolant temperature is above 60

°

C (140

°

F).

D

While in “power enrichment” mode the oxygen sensor
voltage remains below 400 mV for 3 seconds.

Action Taken When the DTC Sets

D

The PCM will illuminate the malfunction indicator lamp
(MIL) the first 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.

Conditions for Clearing the MIL/DTC

D

DTC P1171 can be cleared by using Tech 2 “Clear Info”
function or by disconnecting the PCM battery feed.

Diagnostic Aids

D

A restricted fuel filter or fuel line, restricted in-tank filter,
or a defective fuel pomp may supply adequate

6E–246

ENGINE DRIVEABILITY AND EMISSIONS

amounts of fuel at idle, but may not be able to supply
enough fuel during heavy acceleration.

D

Water or alcohol in the fuel may cause low HO2S
voltage during acceleration.

D

Check for faulty or plugged fuel injector(s).

D

Check for low fuel.

Test Description

Number(s) below refer to the step number(s) on the
Diagnostic Chart.

4. When the engine is idling or at steady cruise, the

HO2S voltage should vary from between
approximately 100 mV to 900 mV.  It is possible to
measure a satisfactory fuel pressure at idle even
though the pressure may drop at high flow
requirements.  It may be necessary to watch fuel
pressure at high engine load.

5. Wrap a shop towel around the fuel pressure

connector to absorb any small amount of fuel
leakage that may occur when installing gauge.
Ignition “ON,” pump pressure should be 280-320
kPa.

DTC P1171 – Fuel System Lean During Acceleration

 

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

Are any component-related DTCs set?

—

Go to

component

DTC charts

Go to 

Step 3

3

1. Check the vehicle’s fuel tank for an adequate

amount of fuel.

2. Add fuel to the vehicle’s fuel tank if the tank is almost

empty.

Was fuel added to the vehicle’s fuel tank?

—

Go to 

Step 4

Go to 

Step 5

4

1. Place the transmission in park.
2. Using Tech 2, observe HO2S 1 voltage while

running warm engine 75

°

C-95

°

C (167

°

F-203

°

F) at

1200 RPM.

3. HO2S 1 voltage should vary within the specified

range.

4. Quickly open the throttle halfway for a few seconds.

Did the voltage suddenly rise toward the high end of the
specified range?

100-900 mV

Go to Chart

A-7

Go to 

Step 5

5

1. Disconnect the fuel pump relay and crank the

engine to relieve the fuel pressure.

2. Install the fuel pressure gauge.
3. Start the engine and idle at normal operating

temperature.

4. Disconnect the vacuum line going to the fuel

pressure regulator.

With the engine running, is the fuel pressure within the
specified range?

280-325 kPa

(41-46 psi)

Go to 

OBD

System

Check

Go to 

Step 6

6

Check for restricted fuel lines or restricted in-line filter.

Was a problem found?

—

Verify repair

Go to 

Step 7

6E–247

ENGINE DRIVEABILITY AND EMISSIONS

DTC P1171 – Fuel System Lean During Acceleration

  (Cont'd)

Step

No

Yes

Value(s)

Action

7

1. Ignition “OFF.”
2. Remove the fuel pump relay and replace it with a

fused jumper which will connect the relay’s battery
terminal to the terminal leading to the fuel pump
fuse.

3. While the fuel pump is operating, use pliers to slowly

close the return line (do not exceed the first
specified value).

Using the pliers to restrict the return line, can the fuel
pressure be manipulated to exceed the second
specified value?

414 kPa

(60 psi)

325 kPa

(46 psi)

Go to

Diagnostic

Aids

Go to 

Step 8

8

Check for:

D

Faulty fuel pump

D

Restricted fuel pump strainer (sock)

D

Incorrect fuel pump

D

Incorrect fuel being used

D

Hot fuel

Is the action complete?

—

Verify repair

—

6E–248

ENGINE DRIVEABILITY AND EMISSIONS

Diagnostic Trouble Code (DTC) P1380 ABS Rough Road ABS System Fault

Circuit Description

The powertrain control module (PCM) monitors ABS fault
signal. When PCM receives fault signal, PCM will set
DTC P1380.

Conditions for Setting the DTC

D

Vehicle speed is more than 5 mph.

D

Load is less than 99%.

D

Engine revolution is less than 6250 rpm.

D

PCM receives ABS fault signals from ABS unit.

D

Ignition on.

D

Misfire DTCs exist.

D

100 test failures within 120 test samples.

Action Taken When the DTC Sets

D

The PCM will store DTC 1380 only, no MIL turn on.

Conditions for Clearing the MIL/DTC

D

A history DTC P1380 will clear after 40 consecutive
warm-up cycles have occurred without a fault.

D

DTC 1380 can be cleared by using Tech-2 or
disconnecting the PCM battery feed.

Diagnostic Aids

Check for the following conditions:

D

PCM and ABS communication line short circuit to other
line may cause faulty signal.  Inspect communication
line.

D

Follow ABS ECU diagnosis procedure, refer to ABS
procedure page.

DTC P1380 – ABS Rough Road ABS System Fault

 

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”, review and record

Tech 2 Failure Records Data.

2. Operate the vehicle within Failure Records

conditions as noted.

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

P1380 and Misfire DTCs until the DTC P1380 and
Misfire DTCs test runs. Note the result.

Does the Tech 2 indicates DTC P1380 and Misfire
DTCs failed this ignition?

—

Refer to ABS

diagnosis

After inspect

ABS, unit re-

peat 

Step 2

Still problem

exists, go to

Step 3

Clear DTC by

Tech 2

3

Check short circuit among communication line of
PCM/ABS and others.

Was short circuit?

—

Repair wiring

Verify repair

Go to 

Step 4

4

Replace the PCM.

IMPORTANT: The replacement PCM must be
programmed.  Refer to 

UBS 98model year Immobilizer

Workshop Manual.

Is the action complete?

—

Verify repair

—