2007 ISUZU KB P190 Harness

6E–228 ENGINE DRIVEABILITY AND EMISSIONS
DIAGNOSTIC TROUBLE CODE (DTC) P1693 TACHOMETER OUTPUT LOW VOLTAGE
Condition for setting the DTC and action taken when the DTC sets
Circuit Description
Based on the information from the Crank Position
Sensor (CKP), X58 reference signal is generated at
each rotation of the crankshaft.
Engine Control Module (ECM) converts X58 reference
signal into the square wave signal which is used to drive
the pulse generator of the tachometer.
When the wave length of the output signal is long, the
tacho meter indicates the engine speed is low, and vise
versa.
This malfunction detects a low impedance short to ground or open contact on the Tacho output, the
Diagnostic Trouble Code P1693 will be set.
Diagnostic Aids
• Poor connections or a damaged harness - Inspect the harness connections for: backed out terminals,
imprope, mating or damaged terminals. Also check
for open circuit, short to ground, and short to voltage.
• This malfunction detects a low impedance short to ground or open contact on the ECM out put circuit.
Code Type DTC Name DTC Setting Condition Fail-Safe (Back Up)
P1693 B Tachometer Output Low Voltage Tacho output circuit short to ground circuit. No fail-safe function.

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ISUZU KB P190 2007

6E–230 ENGINE DRIVEABILITY AND EMISSIONS
6 Using the DVM and check the Tacho output circuit. Breaker box is available:
1. Ignition “Off”, engine “Off”.
2. Install the breaker box as type A. (ECM disconnected) Refer to 6E-88 page.
3. Disconnect the meter connector.
4. Check the circuit for open or short to ground circuit.
Was the problem found?
Breaker box is not available: 1. Ignition “Off”, engine “Off”.
2. Disconnect the ECM connector.
3. Disconnect the meter connector.
4. Check the circuit for open or short to ground circuit.
Was the problem found?
—Repair faulty
harness and verify repair Go to Step 7
7 Using the DVM and check the Tacho output circuit. 1. Ignition “On”, engine “Off”.
2. Disconnect the meter connector.
3. Check the circuit for short to power supply circuit.
Was the DVM indicated specified value?
Less than 1V Go to Step 8Repair faulty
harness and verify repair
8 Check any accessory parts which may cause electric interference or magnetic interference.
Was the problem found? —Remove the
accessory parts
and verify repair Go to Step 9
Step
Action Value(s) Yes No
J2-25
Breaker BoxB-2411
ΩΩ
1125C-56(J2)B-24
V
B-24
11

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6E–232 ENGINE DRIVEABILITY AND EMISSIONS
SYMPTOM DIAGNOSIS
PRELIMINARY CHECKS
Before using this section, perform the “On-Board
Diagnostic (OBD) System Check” and verify all of the
following items:
• The engine control module (ECM) and malfunction indicator lamp (MIL = Check Engine Lamp) are
operating correctly.
• There are no Diagnostic Trouble Code(s) stored.
• Tech 2 data is within normal operating range. Refer to Typical Scan Data Values.
• Verify the customer complaint and locate the correct symptom in the table of contents. Perform the
procedure included in the symptom chart.
VISUAL/PHYSICAL CHECK
Several of the symptom procedures call for a careful
visual/physical check. This can lead to correcting a
problem without further checks and can save valuable
time. This check should include the following items:
• ECM grounds for cleanliness, tightness and proper location.
• Vacuum hoses for splits, kinks, and proper connection, shown on the “Emission Control System
Schematics”. Check thoroughly for any type of leak or
restriction.
• Air intake ducts for collapsed or damaged areas.
• Air leaks at throttle body mounting area, manifold absolute pressure (MAP) sensor and intake manifold
sealing surfaces.
• Ignition wires for cracking, harness, and carbon tracking.
• Wiring for proper connections, pinches and cuts.
INTERMITTENT
Important: An intermittent problem may or may not turn
on the malfunction indicator lamp (MIL) or store a
Diagnostic Trouble Code. Do NOT use the Diagnostic
Trouble Code (DTC) charts for intermittent problems.
The fault must be present to locate the problem.
Most intermittent problems are cased by faulty electrical
connections or wiring. Perform a careful visual/physical
check for the following conditions.
• Poor mating of the connector halves or a terminal not fully seated in the connector (backed out).
• Improperly formed or damaged terminal.
• All connector terminals in the problem circuit should be carefully checked for proper contact tension.
• Poor terminal-to-wire connection. This requires removing the terminal form the connector body to
check.
• Ignition coils shorted to ground and arcing at ignition wires or plugs. • MIL (Check Engine Lamp) wire to ECM shorted to
ground.
• Poor ECM grounds. Refer to the ECM wiring diagrams.
Road test the vehicle with a Digital Multimeter
connected to a suspected circuit. An abnormal voltage
when the malfunction occurs is a good indication that
there is a fault in the circuit being monitored.
Using Tech 2 to help detect intermittent conditions. The
Tech 2 has several features that can be used to located
an intermittent condition.
An intermittent MIL (Check Engine Lamp) with no stored
Diagnostic Trouble Code may be caused by the
following:
• Ignition coil shorted to ground and arcing at ignition wires or plugs.
• MIL (Check Engine Lamp) wire to ECM short to ground.
• Poor ECM grounds. Refer to the ECM wiring diagrams.
Check for improper installation of electrical options such
as light, cellular phones, etc. Check all wires from ECM
to the ignition control module for poor connections.
Check for an open diode across the A/C compressor
clutch and check for other open diodes (refer to wiring
diagrams in Electrical Diagnosis).
If problem has not been found, refer to ECM connector
symptom tables.
• Check the “Broadcast Code” of the ECM, and compare it with the latest Isuzu service bulletins and/
or Isuzu EEPROM reprogramming equipment to
determine if an update to the ECM’s reprogrammable
memory has been released.
To check the “Broadcast Code”, connect the Tech 2,
then look for “ID info.” then select “Broadcast Code”.
This should display a 4 character code, such as “XBYA”
(example only).
This identifies the contents of the reprogrammable
software and calibration contained in the ECM.
If the “Broadcast Code” is not the most current
available, it is advisable to reprogram the ECM’s
EEPROM memory, which may either help identify a
hard-to find problem or may fix the problem.
The Service Programming System (SPS) will not allow
incorrect software programming or incorrect calibration
changes.

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ISUZU KB P190 2007

6E–234 ENGINE DRIVEABILITY AND EMISSIONS
12 Visually/physically inspect the secondary ignitionwires. Check for the following conditions:
• Verify that all ignition wire resistance are less than the specified value.
• Verify that ignition wires are correctly routed to eliminate cross-fitting.
• Verify that ignition wires are not arcing to ground. Spraying the secondary ignition wires 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 13
13 1. Disconnect the spark plug high tension cable from No.1 spark plug.
2. Install a spark tester at the end of the disconnected ignition coil.
3. Clip the spark tester to a good ground.
4. Observe the spark tester while the engine is cranking.
Was a crisp blue spark observed? (Only one or two
sparks followed by no result is considered the same
as “No Spark”.) — Go to Step 21Go to Step 14
14 1. Disconnect the ignition coil harness connector. 2. Check for an open or short circuit between theignition coil and the ECM.
Was a problem found? — Verify repair Go to Step 15
15 1. Ignition “On”. 2. Using a Digital Voltmeter (DVM) check the ignitionwire coil at the ignition coil harness connector.
Was the voltage equal to the specified value? Battery
voltage Go to Step 16Verify repair
16 1. Ignition “Off”. 2. With DVM, check for an open in the ground wire atthe ignition coil harness connector.
Was the ground wire OK? — Go to Step 17Verify repair
17 Replace the ignition coil, verify the repair. Attempt to start the engine.
Is there still a problem? — Go to Step 18Verify repair
18 Use an ohmmeter to check the ignition coil primary winding resistance.
Was the primary winding resistance approximately
equal to the specified value? 0.8-18kΩGo to Step 19 Go to Step 20
19 Use an ohmmeter to check the ignition coil secondary winding resistance.
Was the primary winding resistance hear around the
to the specified value? 2.5kΩ Go to Step 21 Go to Step 20
20 Replace the ignition coil. — Verify repair —
21 1. Remove the spark plugs from all cylinders. 2. Visually inspect the spark plug electrodes.
3. Replace any spark plugs with loose or missing electrodes or cracked insulators.
Did your inspection reveal any spark plugs exhibiting
excessive fouling? —Correct the
fouling
condition Go to Step 22
Step
Action Value(s) Yes No

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6E–270 ENGINE DRIVEABILITY AND EMISSIONS
FUEL PRESSURE RELIEF
Caution: To reduce the risk of fire and personal
injury, it is necessary to relieve the fuel system
pressure before servicing the fuel system
components.
Caution: After relieving the fuel system pressure, a
small amount of fuel may be released when
servicing fuel lines or connections. Reduce the
chance of personal injury by covering the fuel line
fitting with a short towel before disconnecting the
fittings. The towel will absorb any fuel that may leak
out. When the disconnect is completed, place the
towel in an approved container.
1. Remove the fuel filler cap.
2. Remove the fuel pump relay from the underhood relay box.
3. Start the engine and allow it to stall.
4. Crank the engine for about 30 seconds.
5. Disconnect the negative battery cable.
FUEL RAIL ASSEMBLY
Removal Procedure
NOTE:
• Use care when removing the fuel rail assembly in order to prevent damage to the injector al connector
terminal and the injector spray tips.
• Fitting should be capped and holes plugged during servicing to prevent dirt and other contaminants from
entering open lines and passage.
Important: An eight-digit identification number is
stamped on side of the fuel injector. Refer to this
number when you service the fuel rail or when a
replacement part is required.
1. Disconnect 4 injector connectors.
2. Lift side-clip up on the fuel rail.
3. Disconnect fuel pressure regulator hose.
4. Disconnect wiring harness from the bands on the fuel rail.
5. Remove the intake pipe.
6. Loosen flare nut.
A. Lift up the injectors carefully to separate them from intake manifold.
B. Lift up the fuel rail with injectors as assembly. Do not separate the fuel injectors from fuel rail.
C. If an injector become separated from fuel rail, injector backup O-ring and injector retainer clip
must be replaced.
D. Drain residual fuel from fuel rail into an approved container.
7. If removal of fuel pressure regulator is necessary, Refer to Fuel Pressure Regulator Removal
Procedure .

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ISUZU KB P190 2007

ENGINE DRIVEABILITY AND EMISSIONS 6E–271
8. If removal of fuel injector is necessary, Refer to Fuel
Injectors Removal Procedure .
Installation Procedure 1. Install the fuel injectors if necessary. Refer to Fuel Injector Installation Procedure.
2. Install the fuel pressure regulator if necessary. Refer to Fuel Pressure Regulator Installation Procedure .
3. Place the fuel injector rail assembly on the manifold and insert the injectors into each port by pushing
fuel rail.
4. Install two fuel rail retaining bolts. Tighten fuel rail retaining bolt to 19 N·m (1.9kgf·m)
5. Place wiring harness in its place and secure it with two nuts.
6. Connect all connector to each fuel injector.
7. Connect the fuel supply line securely. Do not over tighten. 8. Connect the fuel return line securely. Do not over
tighten.
9. Connect the negative battery cable.
10. Crank the engine until it starts. Cranking the engine may take longer than usual due to trapped air in the
fuel system. Check for leak. If fuel leak is observed,
stop engine immediately. Before correcting fuel
leak, be sure to depressurize system again.

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Engine Mechanical – V6 Page 6A1–11

Figure 6A1 – 3
Legend
1 PCV Hose
2 PCV Hose O-Ring Outer (larger)
3 PCV Hose O-Ring Inner (smaller)
4 Upper Intake Manifold
5 Lower Intake Manifold
6 Upper Intake Manifold Bolt – Long
7 Upper Intake Manifold Bolt – Short
8 Lower Intake Manifold to Upper Intake Manifold Guide Pin
9 Upper Intake Manifold to Lower Intake Manifold Gasket
10 Lower Intake Manifold to Cylinder Head Gasket
11 Lower Intake Manifold Bolt
12 Fuel Rail Bolt
13 Fuel Rail
14 Fuel Injector
15 Fuel Injector Retainer
16 Fuel Injector Upper O-ring 17 Fuel Injector Lower O-ring
18 Fuel Pressure Service Valve Cap
19 Fuel Pressure Service Valve
20 Ball Stud
21 Fuel Injector Wiring Harness
22 Throttle Body
23 Throttle Body Bolt
24 Throttle Body Gasket
25 Throttle Body Engine Wiring Harness Clip
26 EVAP Purge Solenoid
27 EVAP Purge Solenoid Bolt
28 EVAP Purge Solenoid Tube
29 EVAP Purge Solenoid Bracket
30 BARO Sensor Bolt
31 BARO Sensor
32 BARO Sensor O-Ring

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Engine Mechanical – V6 Page 6A1–57

3.3 Oil Filter Adaptor
Remove

Disconnection of the battery affects certain
vehicle electronic systems, refer to 1.1
WARNING, CAUTION and NOTES before
disconnecting the battery.
1 Disconnect the battery negative terminal.
2 Disconnect the wiring harness connector from the oil pressure sender.

3 Remove the oil filter adaptor attaching bolts (2), four places.
4 Remove the oil filter adaptor and discard the gasket (3).
5 Clean the surfaces of the adaptor and cylinder block.

• Do not use a screwdriver or similar to
prise the oil filter adapter from the engine
as damage to the sealing surface may
occur.
• If required, use a rubber mallet to tap the
oil filter adapter to loosen the
components prior to separating.
Tapping should be done at bends,
corners or reinforced areas to prevent
distortion of parts.
Figure 6A1 – 27
Reinstall
Reinstallation of the oil filter adaptor is the reverse of the removal procedure, noting the following:
1 A new gasket must be used.
2 Loosely install the oil filter adaptor attaching bolts, then tighten all fasteners to the correct torque specification.
Oil filter adaptor attaching bolt
torque specification .................................. 20.0- 26.0 Nm

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ISUZU KB P190 2007