Isuzu Trooper (2000 year). Service manual - part 320

6E–409

TROOPER 6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

Diagnostic Trouble Code (DTC) 

P1167 Fuel System Rich During Decel Fuel Cut Off (Bank 1)

D06RY00171

Circuit Description

The powertrain control module (PCM) continuously
monitors the heated oxygen sensor (HO2S) activity for 90
seconds after “closed loop” has been enabled. During the
monitoring period the powertrain control module (PCM)
counts the number of times a rich to lean and respones is
indicated and adds the amountof time it look to complete
all rich to lean transisitions and lean to rich transitions.
This code detects if Bank1 02 sensor indicated rich
exhaust while in Decel Fuel Cut Off (DFCO) for fuel
control sensors.

Conditions for setting the DTC

D

No related DTCs.

D

The engine coolant temperature is more than 60 

°

C

(140 

°

F).

D

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

D

While in “power enrichment” mode the oxygen sensor
voltage remains more than 600mV in DFCO.

Action Taken When the DTC Sets

D

The PCM will not illuminate the malfunction
malfunction indicator lamp (MIL).

D

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

Conditions for Clearing the MIL/DTC

D

A history DTC P1167 will clear after 40 cosecutive trip
cycle during which the warm up cycles have occurred
without a fault.

D

DTC P1167 can be cleared using the Tech 2 “Clear
Info” function or by disconnecting the PCM battery
feed.

Diagnostic Aids

D

Check for faulty fuel injectors and fuel pump.

6E–410

TROOPER 6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

Diagnostic Trouble Code (DTC) 

P1167 Fuel System Rich During Decel Fuel Cut Off (Bank1)

 

Step

Action

Value(s)

Yes

No

1

Was the “On-Board (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. Place the transmission in Park.
2. Using a Tech 2, HO2S 1 voltage while running warm

engine 75 

°

C – 95 

°

C (167 

°

F – 203 

°

F) at 1200

RPM.

3. HO2S 1 votages should vary within the specified

range. (100 – 900mV)

4. Quickly open the wide open the throtle for a few

Did the voltage suddenly rise toward the low endof the
specified range?

100 – 600 mV

Go to

 OBD

System

Check

Go to

 Step 4 

4

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

temperatur.

4. Disconnect the vacuum line going to the fuel

pressure regurlator.

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

280 – 325Kpa

(41 – 46psi)

Go to

 OBD

System

Check

Go to

 Step 5

5

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 opreating, 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 value?

Is the TP sensor reading near the specified value?

414KPa

(60psi)

325KPa

(46psi)

Refer to

Diagnostic

Aids

Go to

 Step 6

6

Check the following items;

D

Faulty fuel pump

D

Incorrect fuel pump

D

Incorrect fuel being used

D

Cold fuel

If a problem is found, repair one as necessary.

Was a problem found?

—

Verify repair

—

6E–411

TROOPER 6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

Diagnostic Trouble Code (DTC) 

P1169 Fuel System Rich During Decel Fuel Cut Off (Bank 2)

D06RY00175

Circuit Description

The powertrain control module(PCM)
continuously monitors the heated oxygen sensor (HO2S)
activity for 90 seconds after “closed loop” has been
enabled. During the monitoring period the powertrain
control module (PCM) counts the number of times a rich
to lean and respones is indicated and adds the amountof
time it look to complete all rich to lean transisitions and
lean to rich transitions.
This code detects if Bank2 sensor indicated rich exhaust
while in Decel Fuel Cut Off (DFCO) for fuel control
sensors.

Conditions for setting the DTC

D

No related DTCs.

D

The engine coolant temperature is more than 60 

°

C

(140 

°

F).

D

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

D

While in “power enrichment” mode the oxygen sensor
voltage remains more than 600mV in DFCO.

Action Taken When the DTC Sets

D

The PCM will not illuminate the malfunction
malfunction indicator lamp(MIL).

D

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

Conditions for Clearing the MIL/DTC

D

A history DTC P1169 will clear after 40 cosecutive trip
cycle during which the warm up cycles have occurred
without a fault.

D

DTC P1169 can be cleared using the Tech 2 “Clear
Info” function or by disconnecting the PCM battery
feed.

Diagnostic Aids

D

Check for faulty fuel injectors and fuel pump.

6E–412

TROOPER 6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

Diagnostic Trouble Code (DTC) 

P1169 Fuel System Rich During Decel Fuel Cut Off (Bank2)

 

Step

Action

Value(s)

Yes

No

1

Was the “On-Board (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. Place the transmission in Park.
2. Using a Tech 2, HO2S 2 voltage while running warm

engine75 C – 95 C (167 F – 203 F) at 1200 RPM.

3. HO2S 1 votages should vary within the specified

range. (100 – 900mV)

4. Quickly open the wide open the throtle for a few

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

100 – 600 mV

Go to

 OBD

System

Check

Go to

 Step 4 

4

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

temperatur.

4. Disconnect the vacuum line going to the fuel

pressure regurlator.

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

280 – 325Kpa

(41 – 46psi)

Go to

 OBD

System

Check

Go to

 Step 5

5

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 opreating, 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 value?

Is the TP sensor reading near the specified value?

414KPa

(60psi)

325KPa

(46psi)

Refer to

Diagnostic

Aids

Go to

 Step 6

6

Check the following items;

D

Faulty fuel pump

D

Incorrect fuel pump

D

Incorrect fuel being used

D

Cold fuel. 

If a problem is found, repair one as necessary.

Was a problem found?

—

Verify repair

—