2007 ISUZU KB P190 sensor

ENGINE DRIVEABILITY AND EMISSIONS 6E–245
HESITATION, SAG, STUMBLE SYMPTOM
DEFINITIONS: Momentary lack of response as the
accelerator is pushed down. Can occur at any vehicle
speed. Usually most pronounced when first trying to
make the vehicle move, as from a stop sign. May cause
the engine to stall if severe enough.
Step Action Value(s) Yes No
1 Was the “ On-Board Diagnostic (OBD) System Check ”
performed? — Go to Step 2Go to
OBD
System Check
2 1. Perform a bulletin search. 2. If a bulletin that addresses the symptom is found,correct the condition as instructed in the bulletin.
Was a bulletin found that addresses the symptom? — Verify repair Go to Step 3
3 Was a visual/physical check performed? —Go to Step 4Go to
Visual /
physical Check .
4 Check the fuel quality. Is the customer using improper fuel or degraded fuel? — Replace fuel Go to Step 5
5 1. Using a Tech 2, display the MAP sensor value in comparison with atmosphere temperature.
2. Check for a faulty, plugged, or incorrectly installed MAP sensor.
Was the problem found? — Verify repair Go to Step 6
6 Observe the throttle position display on the Tech 2 while slowly increasing throttle pedal.
Does the throttle position increase steady with
increasing smoothly?
—Go to Step 7Refer to
Diagnostic
Trouble Code P0123 for further
diagnosis
7 Check the knock sensor wire, shield wire, or installation condition.
Was a problem found? — Verify repair Go to Step 8
8 Run Engine. Check the fuel control Heated Oxygen Sensor
(HO2S). When monitored on the Tech 2, the HO2S
should respond quickly to different throttle positions. If
it doesn’t check for silicon or other contaminates from
fuel or use of improper sealant. The sensors may
have a white powdery coating. Silicon contamination
sends a rich exhaust signal which causes the ECM to
command and excessively lean air/fuel mixture.
Was a problem found? — Verify repair Go to Step 9
9 Check the fuel pressure. Refer to 6E-108 “Fuel
System Diagnosis
”.
Was a problem found? — Verify repair Go to Step 10

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ISUZU KB P190 2007

6E–246 ENGINE DRIVEABILITY AND EMISSIONS
10 Monitor “B1S1 (Bank 1 Sensor 1) Status ” on the Tech
2.
Is the “ B1S1 (Bank 1 Sensor 1) Status ” in the rich
condition? — Go to Step 11Go to Step 12
11 Check items that can cause the engine to run rich. Refer to DTC P1167 “Fuel Supply System Rich During
Deceleration Fuel Cut Off”.
Was a problem found? — Verify repair Go to Step 12
12 Check items that can cause the engine to run lean. Refer to DTC P1171 “Fuel Supply System Lean
During Power Enrichment”.
Was a problem found? — Verify repair Go to Step 13
13 Check for proper ignition voltage output with the spark tester.
Was a problem found? — Verify repair Go to Step 14
14 Check for a loose ignition control module ground. Was a problem found? — Verify repair Go to Step 15
15 Visually/physically inspect all spark plug high-tension cables. Check for the following conditions:
• Verify that the resistance of all spark plug high- tension cables are less than the specified value.
• Verify that the all spark plug high-tension cables are correctly fitted to eliminate cross-fitting.
• Verify that the all spark plug high-tension cables are not arcing to ground.
Spraying the spark plug high-tension cables with a
light mist of water may help locate an intermittent
problem.
Was a problem found? #1 cyl. 4.4k
Ω
#2 cyl. 3.6k Ω
#3 cyl. 3.1k Ω
#4 cyl. 2.8k ΩVerify repair Go to Step 16
16 1. Check the ignition coil secondary resistance. 2. Replace the coil if it is greater than the specifiedresistance.
Did the coil require replacement? 2.5kΩ Verify repair Go to Step 17
17 1. Remove the spark plugs and check for gas or oil fouling cracks, wear, improper gap, burned
electrodes, heavy deposits, or improper heat
range.
2. If spark plugs are fouled, the cause of fouling must be determined before replacing the spark plugs.
Was a problem found? — Verify repair Go to Step 18
18 Check the ECM grounds to verify that they are clean and tight. Refer to the ECM wiring diagrams.
Was a problem found? — Verify repair Go to Step 19
19 Visually/physically check the vacuum hose for splits, kinks and proper connections and routing.
Was a problem found? — Verify repair Go to Step 20
Step
Action Value(s) Yes No

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ISUZU KB P190 2007

6E–248 ENGINE DRIVEABILITY AND EMISSIONS
CUTS OUT, MISSES SYMPTOM
DEFINITIONS: Steady pulsation or jerking that follows
engine speed; usually more pronounced as engine load
increases.
Step Action Value(s) Yes No
1 Was the “ On-Board Diagnostic (OBD) System Check ”
performed? — Go to Step 2Go to
OBD
System Check
2 1. Perform a bulletin search. 2. If a bulletin that addresses the symptom is found,correct the condition as instructed in the bulletin.
Was a bulletin found that addresses the symptom? — Verify repair Go to Step 3
3 Was a visual/physical check performed? —Go to Step 4Go to
Visual /
physical Check .
4 Check the ECM grounds to verify that they are clean and tight. Refer to the ECM wiring diagrams in
Electrical Diagnosis .
Was a problem found? — Verify repair Go to Step 5
5 Check for a loose or short circuit of ignition coil module voltage feed.
Was a problem found? — Verify repair Go to Step 6
6 Check for a loose or short circuit of ignition coil module ground.
Was a problem found? — Verify repair Go to Step 7
7 Visually/physically inspect all spark plug high-tension cables. Check for the following conditions:
• Verify that the resistance of all spark plug high- tension cables are less than the specified value.
• Verify that the all spark plug high-tension cables are correctly fitted to eliminate cross-fitting.
• Verify that the all spark plug high-tension cables are not arcing to ground.
Spraying the spark plug high-tension cables with a
light mist of water may help locate an intermittent
problem.
Was a problem found? #1 cyl. 4.4k
Ω
#2 cyl. 3.6k Ω
#3 cyl. 3.1k Ω
#4 cyl. 2.8k ΩVerify repair Go to Step 7
8 Check the CKP sensor wire, shield wire, or installation condition.
Was a problem found? — Verify repair Go to Step 9
9 Monitor “ B1S1 (Bank 1 Sensor 1) Status ” on the Tech
2.
Is the “ B1S1 (Bank 1 Sensor 1) Status ” in the rich
condition? — Go to Step 10Go to Step 11

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ISUZU KB P190 2007

ENGINE DRIVEABILITY AND EMISSIONS 6E–249
10 Check items that can cause the engine to run rich.Refer to DTC P1167 “Fuel Supply System Rich During
Deceleration Fuel Cut Off” .
Was a problem found? — Verify repair Go to Step 11
11 Monitor “ B1S1 (Bank 1 Sensor 1) Status ” on the Tech
2.
Is the “ B1S1 (Bank 1 Sensor 1) Status ” in the lean
condition? — Go to Step 12Go to Step 13
12 Check items that can cause the engine to run lean. Refer to DTC P1171 “Fuel Supply System Lean
During Power Enrichment” .
Was a problem found? — Verify repair Go to Step 13
13 1. Visually/physically inspect for the following conditions:
• Restriction of air intake system. Check for a restricted air filter element, or foreign objects
blocking the air intake system.
• Check for objects blocking the IAC passage or throttle bore, excessive deposits in the throttle
bore and on the throttle plate.
• Check for a condition that causes a large vacuum leak, such as an incorrectly installed or
faulty crankcase ventilation hose/brake booster
hose.
Was a problem found? — Verify repair Go to Step 14
14 Check the injector connectors, if any of the injectors are connected an incorrect cylinder, correct as
necessary.
Was a problem found? — Verify repair Go to Step 15
15 Perform the “ Injector Coil/Balance Test” (Refer to 6E-
98 page).
Was a problem found. — Verify repair Go to Step 16
16 1. Check for fuel in the pressure regulator vacuum hose.
2. If fuel is present, replace the fuel pressure regulator assembly.
Was a problem found? — Verify repair Go to Step 17
17 Check for proper ignition voltage output with the spark tester.
Was a problem found? — Verify repair Go to Step 18
18 1. Remove the spark plugs and check for gas or oil fouling cracks, wear, improper gap, burned
electrodes, heavy deposits, or improper heat
range.
2. If spark plugs are fouled, the cause of fouling must be determined before replacing the spark plugs.
Was a problem found? — Verify repair Go to Step 19
Step
Action Value(s) Yes No

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ISUZU KB P190 2007

ENGINE DRIVEABILITY AND EMISSIONS 6E–251
LACK OF POWER, SLUGGISH OR SPONGY SYMPTOM
DEFINITIONS: Engine delivers less than expected power. Attempting part-throttle acceleration results in little or no
increase in vehicle speed.
Step Action Value(s) Yes No
1 Was the “ On-Board Diagnostic (OBD) System Check ”
performed? — Go to Step 2Go to
OBD
System Check
2 1. Perform a bulletin search. 2. If a bulletin that addresses the symptom is found,correct the condition as instructed in the bulletin.
Was a bulletin found that addresses the symptom? — Verify repair Go to Step 3
3 Was a visual/physical check performed? —Go to Step 4Go to
Visual /
physical Check .
4 1. Remove and check the air filter element for dirt or restrictions.
2. Replace the air filter element if necessary.
Was a repair required? — Verify repair Go to Step 5
5 Check the ECM grounds to verify that they are clean and tight. Refer to the ECM wiring diagrams.
Was a problem found? — Verify repair Go to Step 6
6 1. Using a Tech 2, display the MAP sensor value in comparison with atmosphere temperature.
2. Check for a faulty, plugged, or incorrectly installed MAP sensor.
Was the problem found? — Verify repair Go to Step 7
7 1. Using a Tech 2, display the ECT sensor and IAT sensor value and warm up condition compared
with the typical data.
2. Check the specified value or wire.
Was the problem found? — Verify repair Go to Step 8
8 Observe the throttle position display on the Tech 2 while slowly increasing throttle pedal.
Does the throttle position increase steady with
increasing smoothly?
—Go to Step 9Refer to
Diagnostic
Trouble Code P0123 for further
diagnosis
9 Check the knock sensor wire, shield wire, or installation condition.
Was a problem found? — Verify repair Go to Step 10
10 Run Engine. Check the fuel control Heated Oxygen Sensor
(HO2S). When monitored on the Tech 2, the HO2S
should respond quickly to different throttle positions. If
it doesn’t check for silicon or other contaminates from
fuel or use of improper sealant. The sensors may
have a white powdery coating. Silicon contamination
sends a rich exhaust signal which causes the ECM to
command and excessively lean air/fuel mixture.
Was a problem found? — Verify repair Go to Step 11
11 Check the fuel pressure. Refer to “Fuel System
Diagnosis
” 6E-108.
Was a problem found? — Verify repair Go to Step 12

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ISUZU KB P190 2007

6E–252 ENGINE DRIVEABILITY AND EMISSIONS
12 Monitor “B1S1 (Bank 1 Sensor 1) Status ” on the Tech
2.
Is the “ B1S1 (Bank 1 Sensor 1) Status ” in the rich
condition? — Verify repair Go to Step 13
13 Check items that can cause the engine to run rich. Refer to DTC P1167 “Fuel Supply System Rich During
Deceleration Fuel Cut Off”.
Was a problem found? — Verify repair Go to Step 14
14 Check items that can cause the engine to run lean. Refer to DTC P1171 “Fuel Supply System Lean
During Power Enrichment”.
Was a problem found? — Verify repair Go to Step 15
15 Check for proper ignition voltage output with a spark tester.
Was the problem found? — Verify repair Go to Step 16
16 1. Remove the spark plugs and check for gas or oil fouling cracks, wear, improper gap, burned
electrodes, heavy deposits, or improper heat
range.
2. If spark plugs are fouled, the cause of fouling must be determined before replacing the spark plugs.
Was a problem found? — Verify repair Go to Step 17
17 Drain sample fuel, visual inspection. Any suspecion about the fuel, such as discoloration,
particle, contamination, water, unusual smell, then
drain the fuel from fuel tank.
Replace the fuel from know vehicle source.
If any suspencion of alcohol contamination,
completely drain the fuel, replace by fuel from known
vehicle source. — Verify repair Go to Step 18
18 Check the exhaust system for a possible restriction: • Damaged or collapsed pipes
• Internal muffler failure
Was a problem found? — Verify repair Go to Step 19
19 Check for the following engine mechanical problems (refer to Engine Mechanical ):
• Low compression
• Leaking cylinder head gaskets
• Worn camshaft
• Loose timing belt
Was a problem found? — Verify repair Go to Step 20
20 1. Review all diagnostic procedures within this table. 2. If all procedures have been completed and nomalfunctions have been found, review/inspect the
following:
• Visual/physical inspection
• Tech 2 data
• All electrical connections within a suspected circuit and/or system
Was a problem found? — Verify repair Go to Step 21
Step
Action Value(s) Yes No

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ISUZU KB P190 2007

6E–254 ENGINE DRIVEABILITY AND EMISSIONS
DETONATION/SPARK KNOCK SYMPTOM
DEFINITIONS: A mild to severe ping, usually worse under acceleration. The engine makes a sharp metallic knocking
sound that changes with throttle opening. Prolonged detonation may lead to complete engine tailure.
Step Action Value(s) Yes No
1 Was the “ On-Board Diagnostic (OBD) System Check ”
performed? — Go to Step 2Go to
OBD
System Check
2 1. Perform a bulletin search. 2. If a bulletin that addresses the symptom is found,correct the condition as instructed in the bulletin.
Was a bulletin found that addresses the symptom? — Verify repair Go to Step 3
3 Was a visual/physical check performed? —Go to Step 4Go to
Visual /
physical Check .
4 1. If Tech 2 readings are normal (refer to Typical Scan Data Values) and there are no engine
mechanical faults, fill the fuel tank with a known
quality gasoline.
2. Re-evaluate the vehicle performance.
Is detonation present? — Go to Step 5Verify repair
5 1. Check for obvious overheating problems: • Low engine coolant
• Restricted air flow to radiator
• Incorrect coolant solution
2. If a problem is found, repair as necessary.
Was a problem found? — Verify repair Go to Step 6
6 Check the fuel pressure. Refer to 6E-108 page “ Fuel
System Diagnosis” .
Was a problem found? — Verify repair Go to Step 7
7 1. Using a Tech 2, display the MAP sensor value in comparison with atmosphere temperature.
2. Check for a faulty, plugged, or incorrectly installed MAP sensor.
Was the problem found? — Verify repair Go to Step 8
8 1. Using a Tech 2, display the ECT sensor and IAT sensor value and warm up condition compared
with the typical data.
2. Check the specified value or wire.
Was the problem found? — Verify repair Go to Step 9
9 Observe the throttle position display on the Tech 2 while slowly increasing throttle pedal.
Does the throttle position increase steady with
increasing smoothly?
—Go to Step 10Refer to
Diagnostic
Trouble Code P0123 for further
diagnosis
10 Check the knock sensor wire, shield wire, or installation condition.
Was a problem found? — Verify repair Go to Step 11
11 Check items that can cause the engine to run lean. Refer to DTC P1171 “Fuel Supply System Lean
During Power Enrichment”.
Was a problem found? — Verify repair Go to Step 12

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ISUZU KB P190 2007

6E–256 ENGINE DRIVEABILITY AND EMISSIONS
POOR FUEL ECONOMY SYMPTOM
DEFINITIONS: Fuel economy, as measured by an actual road test, is noticeably lower than expected. Also, economy
is noticeably lower than it was on this vehicle at one time, as previously shown by an actual road test.
Step Action Value(s) Yes No
1 Was the “ On-Board Diagnostic (OBD) System Check ”
performed? — Go to Step 2Go to
OBD
System Check
2 1. Perform a bulletin search. 2. If a bulletin that addresses the symptom is found,correct the condition as instructed in the bulletin.
Was a bulletin found that addresses the symptom? — Verify repair Go to Step 3
3 Was a visual/physical check performed? —Go to Step 4Go to Visual /
physical Check.
4 Check owner’s driving habits. • Is the A/C On full time (defroster mode On)?
• Are tires at the correct pressure?
• Are excessively heavy loads being carried?
• Is acceleration too much, too often? — Go to Step 5Go to Step 6
5 Review the items in Step 4 with the customer and advise as necessary.
Is the action complete? — System OK —
6 Visually/physically check: Vacuum hoses for splits, kinks, and improper connections and routing as
shown on the “Emission Control System Schematics”.
Was a problem found? — Verify repair Go to Step 7
7 Check for low engine coolant level. Was a problem found? — Verify repair Go to Step 8
8 Check for incorrect or faulty engine thermostat. Refer to Engine Cooling .
Was a problem found? — Verify repair Go to Step 9
9 Remove and check the air filter element for dirt or for restrictions.
Was a problem found? — Verify repair Go to Step 10
10 1. Using a Tech 2, display the MAP sensor value in comparison with atmosphere temperature.
2. Check for a faulty, plugged, or incorrectly installed MAP sensor.
Was the problem found? — Verify repair Go to Step 11
11 1. Using a Tech 2, display the ECT sensor and IAT sensor value and warm up condition compared
with the typical data.
2. Check the specified value or wire.
Was the problem found? — Verify repair Go to Step 12
12 Check the knock sensor wire, shield wire, or installation condition.
Was a problem found? — Verify repair Go to Step 13
13 Check the fuel pressure. Refer to 6E-108 page “Fuel
System Diagnosis
” .
Was a problem found? — Verify repair Go to Step 14

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TO MODEL INDEX
ISUZU KB P190 2007