IB-09-J-003

SB-10030789-2893
IMPORTANT SERVICE
INFORMATION FOR:
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BULLETIN NUMBER:
IB09-J-003B
SERVICE MANAGER
ISSUE DATE:
JANUARY 2012
SERVICE ADVISOR
TECHNICIAN
PARTS DEPARTMENT
GROUP:
ENGINE
WARRANTY PERSONNEL
Symptom Diagnosis – Engine Fuel System
AFFECTED VEHICLES
2005-2010MY Isuzu N-Series
2005-2010MY GMC/ Chevrolet W-Series Medium Duty Vehicles
Equipped with 5.2L 4HK1-TC diesel engine
This bulletin supersedes information bulletin IB09-J-003A. This bulletin is being revised
to update diagnostic information. Please discard previous bulletin IB09-J-003A.
INFORMATION
The following table contains many possible causes for the following symptoms.

Hard Start/No Start

Rough, Misfire, Unstable or Incorrect Idle

Surges, Lack of Power, Hesitation, Lag or Stumble
While some of these symptoms may lead to component replacement, the replacement should not be considered a
completed repair. These types of symptoms have a high probability for a repeat repair since the true source of the
failure is typically fuel contamination. In order to improve the overall repair and reduce the potential for repeat
failures, the procedure below is provided to assist in identifying the source of fuel contamination. Additionally, this
bulletin will provide information to clarify the meaning of injector balancing rates and how to apply the values
when trying to diagnose the Isuzu common rail fuel system.
Important: Balancing rates alone do not indicate a specific failure. Do not replace components solely
based on balancing rate information.
A balancing rate is defined as an adjustment to fuel volume for each cylinder at idle (below 1200RPM) as
calculated by the ECM. A negative value indicates the fuel volume is lowered. A positive value indicates the fuel
volume is increased. These balancing rates fluctuate positive or negative to compensate for temperature, internal
engine friction, cylinder compression, injector performance and fuel quality to ensure stable idle speed. These
values may react to certain type of internal engine, fuel system and electrical issues as the ECM tries to
compensate to maintain the best possible stable idle. While the value may change drastically, the balancing rate
alone does not indicate a specific failure. Additional information and testing is necessary in order to understand
the reason for the change in balance rates.
The Inspection procedure in this bulletin will help guide the technician through the possible causes for the above
listed symptoms. At some point, balancing rates may be monitored. However, do not replace components solely
based on balancing rate information. This type of action will likely result in: additional diagnosis, delayed repair
and expenses that may not be covered under warranty.
Use the inspection form at the end of this bulletin to record your finding as you work through this diagnosis. This
information will be helpful should additional technical assistance be required. For additional technical assistance
contact Isuzu Commercial Truck of America Technical Assistance at 1-877-478-9828 prompt #3.
INSPECTION
Begin by reviewing the available repair history for the vehicle. Check The Isuzu Vehicle Information System (IVIS)
for previous warranty repairs, your dealer’s system for maintenance history and question the vehicle owner for
maintenance history not performed at your dealer. Understanding this history information may be helpful in
understanding the current condition. Next, inspect the following areas:

Fuel Filler Neck Inspection

Water Separator Draining Procedure

Fuel line (hoses and pipes)
Improper installation or damage in these locations may allow water and other types of debris to enter the fuel
system. Refer to the Fuel Filler Neck Inspection Procedure and the Water Separator Draining Procedure for
additional information.
Step
DESCRIPTION
Value
Yes
No
_
Go to Step
2
No Problem
Identified
_
_
_
_
Go to Step
12
Go to Step
4
_
Go to Step
5
Go to
“Engine
Cranks but
Will Not
Run” in the
Service
Information
_
Go to DTC
Go to Step
6
Go to Step
7
Go to “Fuel
System
Check” in
the Service
Information
Duplicate the Customer’s Concern as listed above.
1
Can the customer’s concern be duplicated?
Check vehicle repair history for the following previous repairs.
2







Injector replacement
Suction control valve (SCV)(Fuel rail pressure (FRP) regulator) replacement
Supply pump replacement
ECM replacement
Fuel filter replacement
Other fuel system components
Wiring repairs
Make a note of these previous repairs as these may affect the outcome of the diagnosis.
Proceed to Step 3.
Visually inspect the fuel system for leaks or aftermarket additions. Take a fuel sample from
the water separator (fuel filter) by referring to the Water Separator Draining procedure. (Be
sure to drain any water before taking the fuel sample) Check the following:
3

API Rating (use special tool J-38641-B)

Water

Gasoline

Debris (Dirt, Sand, Rust, Fungus)

Biodiesel above B5 (black contaminant in return line)
Was a problem found?
4
Does the engine start and continue to Idle?
Install a scan tool and check for any DTCs even if the MIL is not illuminated.
5
Were any DTCs present?
Start the engine and allow the engine to warm up to at least 140F.
6
Increase engine speed in 200 RPM increments from IDLE to W.O.T. and observe the Actual
Fuel Rail Pressure and Desired Fuel Rail Pressure parameters with a scan tool. Allow 2-3
seconds between each 200 RPM increment to allow the rail pressure to stabilize. Record the
values.
Is the difference between the actual and desired fuel rail pressure within the specified value?
 290 psi
( 2MPa)
Check the following Scan tool parameter values against the service information normal value
ranges. If possible, compare against a known good vehicle.
7

APP (smooth change from 0% at no pedal to 100%)

BARO (outside barometric pressure reading with the key ON and engine OFF
within 4kPa (Ex. Sea Level = 101kPa))

Boost Pressure (same value as the BARO with the key ON and engine OFF within
4kPa, then change from 15psi at idle to over 30psi at W.O.T under full
acceleration)

ECT (should indicate the same value as the temperature of the engine coolant.
Compare the ECT, IAT and FT sensor values when the vehicle has been sitting
overnight. The readings should be within 5 degF (2 degC) of each other)
_
Go to Step
8
Refer to
Service
Information
for repair
See
Service
Manual
Go to Step
10
Go to Step
9
_
_
_
_
Go to Step
13
Go to Step
11
Are all sensor values within normal ranges?
Important: Balancing rates alone do not indicate a specific failure.
Do not replace components solely based on balancing rate
information.
Turn the engine “OFF” for one minute.
Turn engine “ON” and let IDLE for 2 minutes. (Engine temp should be greater than 140F)
Raise the engine RPM above 1500 for 30 seconds.
8
Allow RPM to return to IDLE (balancing rates will only update below 1200 RPM) for one
minute.
Monitor the Balancing Rates for cylinders 1 through 4.
Balancing rates above (positive) the specification indicate additional fuel is being added to
the combustion chamber. Balancing rates below (negative) the specification indicate fuel is
being removed from the combustion chamber.
Are any of the balancing rates greater than the specified value?
If all tests were performed properly and no faults were found, review the following items for
other potential causes of the customer’s concern:
9

Injector flow rates incorrectly programmed in ECM

Poor fuel quality

Restricted Intake (air filter)

Restricted exhaust (catalyst/ DPF/exhaust brake)

Truck overweight (exceeding GVW)

Contaminated injector (intermittent)

Brake drag

Transmission performance
If the balancing rate is high in one or more cylinders, check the following:

Injector Flow Rate Programming

Exhaust Manifold Temperature Measurement
o Using an infra red thermometer, measure the exhaust manifold temperature at
exhaust port near the cylinder head. The area around each port should be
within 20F of each other. Any cylinder noticeably cooler indicates poor
cylinder performance.
10

Perform Cylinder Compression Test
o Refer to the Compression Test section of the service manual for test
procedures and specifications
Repair as necessary.
Did you find and correct the condition?
Replace the affected injector that indicates a high balancing rate.
11
Important: Injector Flow Rate must be programmed into the ECM as part of injector
replacement.
_
Go to
Step
13
_
_
Go to
Step 1
_
_
Go to
Step 1
Problem
Resolved
Did you complete the replacement?
The fuel system is contaminated. Find the source.
Drain the fuel from the fuel tank. Collect the fuel in a clean container for inspection. Look for
large debris, rust, discoloration, water or gasoline (Odor). See Fuel Tank Inspection
Procedure.
12
Using a filter cutting tool SUM-900510 or equivalent cut open and inspect the fuel filter
cartridge.
If foreign material or corrosion is found, the affected component should be cleaned and
flushed free of contamination or repaired as necessary.
Was a problem found and repaired?
Reconnect all previously disconnected harness connector(s) or components.
Turn OFF the ignition for 30 seconds.
Turn the ignition “ON” with the engine “OFF”.
13
Clear any DTCs with the scan tool.
Bleed the air from the fuel system. Refer to Fuel System Air Bleeding in this section.
Attempt to duplicate the customer’s concern again.
Can the customer’s concern be duplicated?
Fuel Filler Neck Inspection Procedure
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this
Bulletin
Condition
Engine misfire and/or lack of power possibly due to water/debris entering the fuel filler system
and damaging the fuel system (filters, injectors, supply pump, etc.)
Inspection:
Inspect for evidence of water and debris inside the fuel fill neck, roll over valve and cap. Check
that the roll over valve is positioned properly and free from debris. If your inspection reveals
water and dirt intrusion of the fuel fill neck, roll over valve and/or cap, it is possible the fuel tank
is ingesting water and/or debris.
1. Fuel filler neck
2. Mud flap location (recommended)
Roll over valve orientation
Correction:
The information above is provided as a guideline for proper installation of the fuel filler neck
assembly. Repair as necessary to ensure proper orientation of the roll over valve and
installation of the fuel filler neck assembly to help prevent water and debris intrusion. Isuzu
recommends mud flap installation between the filler neck and the rear axle. Refer to the Isuzu
Body Builder Guide for more detailed information.
Note: Isuzu provides up-fitters and body companies the parts and the instructions for putting
the fuel fillers together. The above illustration shows the housing/collar installed at the end of
the filler neck. If the fuel tank fill neck collar is not installed, this may cause damage to the
vehicle fuel system.
Fuel Tank Inspection Procedure – In Vehicle
1. Inspect fuel tank fuel level.
2. Drain fuel from tank using drain plug (#2).
3. Remove fuel filler neck hose at rear of tank (#3).
1. Fuel filler neck
2. Fuel tank drain plug
3. Fuel hose
4. Using an inspection mirror (1¼“round, 26” extendable) and small flash light, look
through the fuel tank opening and inspect the sides and top of the fuel tank for
contamination or corrosion. With the mirror completely extended and the mirror
positioned at 45 degrees, view the fuel pick up tube and sending unit for corrosion
5. If foreign material or corrosion is found in the fuel tank, remove the tank for cleaning and
repair.
6. With the fuel lines (supply and return) disconnected at the fuel tank and at the
filter/engine (fuel filter removed), flush through the lines using clean diesel fuel in an
effort to remove any remaining contaminated fuel and foreign material.
7. Install the repaired fuel tank, the fuel filter and all fuel lines.
Water Separator Draining Procedure
The purpose of the water separator is to clean the fuel of any dirt particles that can cause wear
on the fuel injector sliding surface; and to separate any water from the fuel that may have
formed in the fuel tank due to condensation. The water separator is located on the bottom of
the fuel filter.
1.
2.
3.
4.
5.
6.
7.
Place a drain pan directly below the drain plug.
Loosen the drain plug.
Loosen the air bleeding plug.
Drain the condensed water.
Retighten both plugs.
Pump the priming pump until the handle is firm.
Start the engine and check for any fuel or air leaks.
2007-2010MY including DPF
1. Air Bleed Plug
2. Drain Plug
3. Primer Pump
2005-2007MY excluding DPF
Engine Fuel System Symptoms Diagnosis- Inspection Form
Dealer Code
VIN
Repair Order #
Fuel Filler Neck Inspection (circle all that apply)
Mud flap placement (OK / NG) Roll over valve (OK / NG)
Fuel Cap (OK / NG)
Fuel Visual Inspection (circle all that apply) – from Step 3
Gasoline
OK
Discolored
Water
Foreign Material
Vacuum Test Results from “Fuel System Check” (if applicable)
Engine Speed Before filter
replacement
After filter
replacement
After filter head
replacement
Idle
W.O.T.
Fuel Rail Pressure – from Step 6
Idle
Actual
W.O.T.
Desired
Actual
Desired
Cylinder 2
Cylinder 3
Cylinder 4
Balancing Rates – from Step 8
Cylinder 1
Compression Test Results – from Step 10 (if applicable)
Cylinder 1
Cylinder 2
Cylinder 3
Cylinder 4
Fuel Tank Inspection (circle all that apply) - from Step 12.
OK
Discolored
Water
Foreign Material
Rust

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CSC-10030789-7562
February 2012
2010 CX-7 & 2010 Mazda6 2.5L Engine
Readiness Code for Evaporative Monitoring System Emission Recall 6611K
Dear Mazda Owner:
Mazda Motor Corporation has decided to conduct an Emission Recall Campaign to reprogram the
Powertrain Control Module (PCM) on certain 2010 CX-7 vehicles produced from May 21, 2009
through October 21, 2009 equipped with 2.5L engine, and on certain 2010 Mazda6 vehicles
produced on September 14, 2009 and September 22, 2009 equipped with 2.5L engine.
If you are a recipient of this notice, your vehicle is included in this recall.
What is the problem?
On certain 2010 CX-7 vehicles and 2010 Mazda6 vehicles, a readiness status code, which is used
for OBD-II Readiness Test, may be incorrectly set due to improper evaporative monitoring system
programming. The Malfunction Indicator Light will not illuminate to indicate this problem, and it
does not affect the safety or driveability of your vehicle.
What will Mazda do?
Your Mazda dealer will reprogram the PCM to include the latest calibration free of charge. The
repair should take approximately half an hour to complete; however, it may take longer depending
on the service workload at your Mazda dealership.
As a reminder, Mazda may provide alternate transportation when your vehicle is at an authorized
Mazda dealership for a warranty repair. To be eligible for alternate transportation, your vehicle must
be within the mileage and time limitations under the Mazda New Vehicle Limited Warranty or
Powertrain Limited Warranty for 2007 and newer model years, and adhere to the Rental Car
Reimbursement policy. Ask your dealer for details about the Mazda Rental Car Reimbursement
Program.
What should you do?
We encourage you to make an appointment with any authorized Mazda dealer to have the PCM
reprogrammed at your earliest convenience. You do not need to bring this notice to the dealer, but
it may assist in the check-in process.
Emission Law Information:
To ensure your full protection under the emission warranty made applicable to your vehicle by State
or Federal Law, and your right to participate in future recalls, it is recommended you have
Mazda North American Operations
Technical Services Division
1444 McGaw Ave.
Irvine, CA 92614-5570
www.MazdaUSA.com
Page 2
your vehicle or engine serviced as soon as possible. Failure to do so could be determined as lack
of proper maintenance of your vehicle. Also, your vehicle may fail a state or local emission
inspection if this recall is not completed.
Important notice to owners registering vehicles in California and Massachusetts: California
Department of Motor Vehicles and the Commonwealth of Massachusetts, in conjunction with the
California Air Resources Board and the Environmental Protection Agency for the State of
Massachusetts, have implemented the Registration Renewal/Recall Tie-In Program, which requires
the completion of Emission Recalls prior to registration renewal. Mazda dealers will provide a
Vehicle Emission Recall - Proof of Correction Certificate upon completion of the recall. Be sure to
keep the proof of correction certificate provided by the Mazda Dealer until needed for the
registration renewal process.
What if you already paid for repair?
If you have already paid for the inspection, reprogramming, or replacement of the PCM due to
incorrectly set readiness status code, prior to receiving this notice, you may be eligible for
reimbursement of reasonable repair expenses based on Mazda’s repair standards.
Please complete the enclosed “Reimbursement Application Form”, include the necessary
documentation, and mail it to us in the pre-addressed envelope provided, allowing 6-8 weeks for
processing.
Where is the closest Mazda dealer?
To locate your nearest Mazda dealer, visit our web site and try our “Locate a Dealer” feature at
www.MazdaUSA.com or consult your local yellow pages.
Moved or no longer own this vehicle?
If you have moved or no longer own your Mazda vehicle, please complete the enclosed prepaid
Information Change Card as soon as possible. This enables us to update our records and notify the
current owner.
Federal law requires that any vehicle lessor receiving this recall notice must forward a copy
of this notice to the lessee within ten days.
Still have questions?
If you have any questions regarding this campaign, please contact our Customer Assistance Center
at (800) 222-5500, option #6.
We actively work to improve our products and search for solutions to improve your ownership
experience. Please accept our apologies for any inconvenience this recall may cause you.
Sincerely,
Mazda North American Operations
Mazda North American Operations
Technical Services Division
1444 McGaw Ave.
Irvine, CA 92614-5570
www.MazdaUSA.com