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NORMAL FUEL SYSTEM PRESSURES – THREE FILTER SYSTEM

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Normal and abnormal fuel system pressures are listed in the following tables. The pressures can vary slightly due to different chassis fuel line configurations, fuel temperatures, fuel filter condition, and fuel viscosity.

Normal Fuel System Pressures
Port Engine 600 RPM Engine 1800 RPM
LPP Inlet (in Hg) -4 to -8 -11 to -14
LPP Outlet (PSI) 72 to 80 100 to 126
HPP Inlet (PSI) 69 to 77 92 to 112
HPP Outlet (PSI) 1 to 2.5 4 to 7
Priming Port (PSI) 72 to 80 100 to 120
Fuel Compensation pressure w/ doser regulator 75 to 85 80 to 95

If the LPPI is greater than the specified range, check for inlet restrictions.

If the high pressure pump Inlet pressure is lower than the acceptable pressure, check the pressure difference across the low pressure pump outlet pressure sensor and fuel compensation pressure sensor. If engine does not have a low pressure pump outlet pressure sensor, install J-48876 and use priming port pressure.

157/ FUEL RAIL PRESSURE TOO LOW

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EPA07/10/GHG14 DDEC VI/10 Electronics and Troubleshooting Manual (DDC-SVC-MAN-0084) | 81 SPN 157 (MCM) (EPA07;EPA10;GHG14) | 81.1 SPN 157/FMI 16 – EPA07 – EPA10 – GHG14

Description Fuel Rail Pressure Too Low
Monitored Parameter Injector Cylinder #1 Needle Control Valve
Typical Enabling Conditions Fuel Rail Pressure desired – Fuel Rail Pressure Actual > 200 bar
Monitor Sequence None
Execution Frequency Continuous When Enabling Conditions Met
Typical Duration Eight Seconds
Dash Lamps MIL, CEL
Engine Reaction Derate 25%
Verification Engine Idle (One Minute)

The Motor Control Module (MCM) monitors the rail pressure and when rail pressure deviation is greater than 200 bar for eight seconds, the MCM sets the code. This fault can occur due to the conditions listed below:

  • External fuel leakage between the high pressure pump and fuel injectors
  • Pressure limiting valve leakage (internal)
  • Fuel filter integrity (loose caps, plugged filters)
  • Fuel supply issues (fuel level, fuel aeration, leaking fuel lines, fuel restrictions)
  • Intermittent loss of engine speed signal
  • High pressure pump internal failure
  • Fuel injector (amplifier or needle) leakage
  • Fuel Contamination
  • Rail pressure sensor
  • Motor Control Module (MCM)

 

Service Tools Used in the Procedure
Tool Number Description
J-48876 Test Gauge, Primer Port, HDE
J-48704 Caps, HP Fuel Rail, HDE
DiagnosticLink 8.x

NOTE: It is important to obtain information from the customer on when the check engine lamp occurs and if there were any performance concerns or exhaust smoke.

 

    1. Did SPN 157/FMI 16 appear after the fuel system was repaired or fuel filter maintenance was performed?
        1. Yes; the code may be set due to air in the fuel system. Clear codes and road test to verify complaint. If code does not set, release the vehicle. If code sets, Go to step 2.

       

      1. No; Go to step 2.

 

    1. Turn the ignition ON (key ON, engine OFF).
NOTE: On EPA10 engines with MCM software 7.6 and later, fuel tank level at the time the fault triggered can be viewed in extended data #5, “Enhanced Environmental data” Fuel Tank Level.

 

    1. Check and record fuel level in all fuel tanks. Is fuel level blow ¼ tank (25%)?
        1. Yes; add fuel and road test vehicle. If code does not become active during road test, release the truck. If the code becomes active during the road test with over ¼ tank (or 25%) of fuel, Go to step 4.

       

      1. No; view fuel tank level in extended data (EPA10) or question the driver about the fuel level when the code was set. If the level was under ¼ tank (or 25%), fuel sloshing in the tank could be the cause of aerated fuel that could cause this code. If the fuel level was over ¼ tank (or 25%) when the code was set, Go to step 4.

 

    1. Check for fuel contamination, including Diesel Exhaust Fluid (DEF), water, gasoline, kerosene, coolant, etc. Is contamination found?
        1. Yes; refer to section “Contaminated Fluids.”

       

      1. No;Go to step 5.

 

    1. Visually inspect for external fuel leaks on the engine and on the chassis.
        1. If a leak is found, repair leak. 

       

      1. If no leaks are found, Go to step 6.

 

    1. Using DiagnosticLink 8.x, check for multiple codes.
        1. If any of the additional fault codes are active, perform the associated diagnostics first:
          • SPN 94 / FMI 15 Fuel Filter plugged
          • SPN 94 / FMI 16 Fuel Filter plugged
          • SPN 97 / FMI 15 Water in the fuel
          • SPN 157 / FMI 1 Rail Pressure too High.
          • SPN 164 / FMI (All) Rail pressure sensor faults
          • SPN 174 / FMI 0 Fuel Temperature too High
          • SPN 679 / FMI 7 PLV stuck open
          • SPN 723 / FMI (all) Cam Sensor Codes
          • SPN 636 / FMI (all) crank sensor codes
          • SPN 1077 / FMI 5, 6 or 14

       

      1. If only SPN 1077/7, 157/16 or 1077/31 is present, Go to step 7.
NOTE: Do not reset this counter unless the PLV is being replaced.

 

    1. Using DiagnosticLink 8.x, check the value of Pressure Limiting Valve (PLV) openings. With key ON, engine OFF select the Actions tab in the top tool bar. Select Fuel System, then Pressure Limiting Valve (PLV) Change or view (E2P_RPG_CTR_PLV_OPEN) under “Extended Data Record Number 5th” list. View and record the PLV open counts. Is the counter greater than 50?
        1. Yes; replace the PLV. Verify repairs. 

       

      1. No;Go to step 8.
NOTE: Engines not equipped with a Low Pressure Pump Outlet (LPPO) sensor should utilize J-48706 Fuel Diagnostic Gauge Set to monitor LPPO.

 

    1. Perform Automatic Fuel system integrity check (FSIC) routine using DiagnosticLink 8.x. With key ON, Engine OFF (KOEO) start the Automatic FSIC. The software/tool will ask to start the engine when required. Once the engine is running, the software will have the engine enter and exit several engine operating conditions. Once the engine shuts down, leave the key on for five minutes. Disconnect DDDL and open the log file. The next part of the troubleshooting will require reviewing the FSIC log file. Go to step 9.

 

    1. Monitor rail pressure bleed-off time. Is bleed-off time below 35 seconds?
        1. Yes; using DiagnosticLink, perform the HP Leak Test.

       

      1. No; Go to step 10.

 

    1. Is the rail pressure bleed-off time is greater than 2 minutes 30 seconds?
        1. Yes; perform the Idle Speed Balance Test to identify faulty injector.

       

      1. No; Go to step 11.

 

    1. Does Kw/Nw show/stay “ON / Enabled / True” while the engine is running during the Automatic FSIC routine?
        1. Yes; Go to step 12.

       

      1. No; refer to troubleshooting for SPN 723/FMI 10.

 

    1. Was the fuel temperature rise greater than 10 degrees?
        1. Yes; Go to step 14.

       

      1. No; Go to step 13.

 

    1. At 600 rpm, is ASL003 Fuel Compensation Pressure within range per the fuel pressure chart? 
        1. Yes; Go to step 15.

       

      1. No; Go to step 14.

 

    1. Monitor AS124 LPPO sensor (if equipped) or use manual gauge J-48706. Is the pressure in range at 600 and 1800 rpm? 
        1. Yes; Go to step 15.

       

      1. No; Repair cause of incorrect fuel pressure. 

 

    1. Monitor AS124 LPPO (if equipped) and ASL003 Fuel Compensation Pressure at all engine speeds, are pressures stable with no oscillations?
        1. Yes; Go to step 16.

       

      1. No; pressures are unstable WITH oscillations of more than 1.5 psi at a steady rpm, 

 

    1. Check the Idle Speed Balance (ISB) Values. Are there any cylinders above 70% or below -70%?
        1. Yes; Follow repair procedures in “Idle speed balance (ISB) test” and verify repairs. 

       

      1. No; Go to step 17.

 

    1. Is ASL001 Rail Pressure erratic or does it have a saw tooth pattern?
      d500085
      d500086

       

        1. Yes; Go to step 18.
      NOTE: See examples of erratic pressure showing (1) ASL001 Rail pressure and (2) AS098 Desired rail pressure.

       

      1. No; Go to step 19.

 

    1. Perform the aerated fuel test.  Was fuel aerated?
        1. Yes; repair cause of aerated fuel. 

       

      1. No; replace the Quantity Control Valve. 

 

    1. Perform Pressure Limiting valve flow test. Did the PLV flow test pass?
        1. Yes; Go to step 20.

       

      1. No; replace the PLV. 

 

    1. Inspect the Low pressure fuel system for leaks . Are leaks present?
        1. Yes; Repair as necessary. 
      NOTICE:

      Prime fuel system prior to going to next step.

       

      1. No; Go to step 21.

 

    1. Cap the rail at all six injector feed connections using J-48704 injector rail caps and crank the engine for 10 seconds. Does the ASL001 rail pressure reach AS098 desired rail pressure?
        1. Yes; Go to step 22.

       

      1. No; Replace high pressure pump. .

 

    1. With the injectors still capped after cranking engine for 10 seconds, does the rail pressure bleed down under 100 bar in less than five minutes?
        1. Yes; Replace the high pressure fuel pump.

       

      1. No; Go to step 23.

 

    1. Using DiagnosticLink 8.x, navigate to Service Routines and Fuel System Integrity Check test and select Manual FSIC. Test drive the truck to see if the code sets. Did the code become active?
        1. Yes; Go to step 24.

       

      1. No; replace fuel filters and release vehicle to customer.

 

    1. Remove the MCM 120-Pin connector. Inspect for damage including fuel, water corrosion or bent terminals. Is any damage found?
        1. Yes; repair as needed.

       

      1. No; Go to step 25.

 

    1. Install a test MCM using the extension harness and test drive the truck. Does the Code come active?
        1. Yes; Go to step 26.

       

      1. No; replace MCM and verify repair.

 

  1. Inspect chassis fuel system for restrictions or debris. Refer to OEM procedures. Is there a chassis fuel system issue?
      1. Yes; identify source of issue and repair as necessary.

     

    1. No; replace fuel filters and release to customer.

164/1 QUANTITY CONTROL VALVE LOW SIDE DRIVER ERROR

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EPA07/10/GHG14 DDEC VI/10 Electronics and Troubleshooting Manual (DDC-SVC-MAN-0084) | 87 SPN 164 (MCM) (EPA07;EPA10;GHG14) | 87.2 SPN 164/FMI 1 – EPA07 – EPA10 – GHG14

Description Quantity Control Valve (Low Side) Error
Monitored Parameter Quantity Control Valve (QCV)
Typical Enabling Conditions Always Enabled
Monitor Sequence None
Execution Frequency Continuous when enabling conditions met
Typical Duration 2 Seconds
Dash Lamps MIL, CEL
Engine Reaction Derate 25%
Verification Engine Idle (1 minute)

This condition can occur when:

  • Motor Control Module (MCM) pin 2 circuit is shorted to power
  • Internal short of the quantity control valve

d150002a

Check as follows:

    1. Turn the ignition OFF.

 

    1. Disconnect the QCV harness connector.

 

    1. Inspect the harness connector for signs of damage: bent, spread, broken, corroded or unseated (push out) pins and signs of moisture in the connector or wire damage near the connector.
        1. If signs of damage are present, repair as necessary.
      1. If no signs of damage are present. Go to step 4.

 

    1. Ensure the multimeter or Digital Voltage Ohm Meter (DVOM) resistance is set to zero.
        1. If meter can auto–zero, perform this function before making a resistance measurement.
      1. If meter cannot auto–zero, note the resistance of the leads and subtract it from the measurement taken. Go to step 5.

 

    1. Measure the resistance across pins 1 and 2 of the QCV.
        1. If the resistance is between 1.0 ohm and 2.0 ohms, Go to step 6.
      1. If resistance is NOT between 1.0 ohm and 2.0 ohms, replace the QCV.
        Refer to section “Removal of the Quantity Control Valve – Three-Filter System”
        Refer to section “Removal of the Quantity Control Valve – Two-Filter System” .

 

    1. Disconnect the 120-pin MCM connector.

 

    1. Inspect the harness connector for signs of damage: bent, spread, broken, corroded or unseated (push out) pins and sign of moisture in the connector or wire damage near the connector.
        1. If signs of damage are present, repair as necessary.
      1. If no signs of damage are present, Go to step 8.

 

  1. Measure the resistance between pins 1 and 3 of the QCV harness connector.
      1. If the resistance is greater than 10k ohms, replace the MCM. Refer to section “Removal of the Motor Control Module” .
    1. If the resistance is less than 10k ohms, repair the short circuit between pins 1 and 2 of the QCV and pins 1 and 2 of the MCM 120-pin connector.

3711/31 HIGH IDLE REGENERATION (ABORTED) LOW EXHAUST TEMPERATURE

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EPA07/10/GHG14 DDEC VI/10 Electronics and Troubleshooting Manual (DDC-SVC-MAN-0084) | 416 SPN 3711 (MCM) (EPA10;GHG14) | 416.1 SPN 3711/FMI 31 – EPA10 – GHG14

The fault indicates that the High Idle Regeneration (HIR) was aborted due to the Diesel Oxidation Catalyst (DOC) inlet temperature not reaching the minimum of 270°C (518°F) to initiate dosing during an HIR. The CEL and MIL lamps will remain ON until the fault is resolved or a successful regeneration is completed.

Show/Hide Checkboxes

 

    1. Connect DiagnosticLink® .

 

    1. Is the vehicle an EPA10 model?
        1. Yes; Go to step 3.
      1. No; Go to step 4.

 

    1. Is the Motor Control Module (MCM) software level 7.5.0.108 with fuel map ZGS 002 (DD15/16) & ZGS 003 (DD13) or higher?
        1. Yes; Go to step 4.
      1. No; update device software and then Go to step 4.

 

    1. Check fault codes; are SPN 3242/FMI 8 or SPN 3242/FMI 20 active or previously active?
        1. Yes; troubleshoot these codes first.
      1. No; Go to step 5.

 

    1. Start the engine.

 

    1. Monitor the Diesel Oxidation Catalyst (DOC) inlet temperature sensor, the DOC outlet temperature sensor. Continue idling for 10 minutes. Is the DOC inlet temperature drifted low?
        1. Yes; replace the DOC inlet temperature sensor and perform an HIR.
      1. No; Go to step 7.

 

    1. Using DiagnosticLink, perform an Intake Throttle Service Routine. Is the commanded position achieved?
        1. Yes; Go to step 8.
      1. No; replace the Intake Throttle Valve (ITV).

 

    1. Inspect the exhaust system for leaks.
        1. If a leak is found, repair as necessary.
      1. If no leaks are found, Go to step 9.

 

    1. Pressurize the intake tract and inspect for leaks.
        1. If a leak is found, repair as necessary.
      1. If no leaks are found, Go to step 10.

 

    1. Perform a Parked Regen. Once the ITV closes, view the Inlet Manifold Pressure (IMP) reading. Is the reading less than 23 PSIa (2.59 bar [37.7 psi])?
        1. No; inspect the ITV. Also for DD13 engines, the wastegate is command “on” during a Parked Regen; inspect the wastegate actuator and the plumbing to and from the actuator.
      1. Yes; Go to step 11.

 

    1. View the Jake Brake® -1 (PWM 13). Is the MCM commanding Jake Brake 1 on?
        1. Yes; Go to step 12.
      1. No; the oil temperature may be too cold. The oil temperature needs to be above 50ºC (122°F) for the Jake Brakes to turn on.

 

    1. Using DiagnosticLink during the regen, view AS087 Actual Fuel Mass. Is the fuel mass above 100 mg/st?
        1. Yes; send in the log file to the Detroit™ Customer Support Center at CSC@daimler.com. Call 800-445-1980 for further analysis and instruction.
      1. No; Go to step 13.

 

    1. Install a test MCM using the extension harness and perform a regen. Is the fuel mass above 100 mg/st?
        1. Yes; replace the MCM.
      1. No; Go to step 14.

 

    1. Remove the valve cover. Inspect the front top of the exhaust rocker arm shaft. It should state “TOP FRONT”. Refer to section “Checking for Poor Engine Brake Performance” .
        1. If the rocker arm does NOT state “TOP FRONT” then remove and inspect it for correct installation and part.
      1. If the rocker arm does state “TOP FRONT”, Go to step 15.

 

    1. Using DiagnosticLink, Service Routines, Cylinder Cut-Out, cut out cylinders one, two, and three. On the Jake Brake solenoid there is a button to push called the Jake Brake Override. Push and hold the Jake Brake override button. Does the engine quit running?
        1. Yes; replace the exhaust rocker arm shaft. The plug in the rocker arm shaft is missing (cannot be seen), causing oil to activate the rear Jake Brakes.
      1. No; Go to step 16.

 

    1. When the Jake override button is pushed down, do you see all the Jake Brake rocker arm pistons come out of the Jake Brake rocker arms for cylinders one, two, and three?
        1. Yes; replace the solenoid and assemble the engine to perform a regen.
      1. No; Go to step 17.

 

    1. Remove the front (Bank 1) engine brake solenoid from the cam frame. This will require the removal of the front injector harness. Make sure both injector harnesses (front and rear) are unplugged. Crank the engine; is there oil coming out of the port in the cam frame housing?
        1. Yes; replace the solenoid. Go to step 18.
      1. No; replace the cam frame housing.

 

  1. Push on the Jake Brake override button again. Do the Jake Brake pistons activate for cylinders one, two and three?
      1. Yes; assemble the engine and try a regen.
    1. No; remove the Jake Brake solenoid and the exhaust rocker arm shaft. Blow compressed shop air through the cam frame to the solenoid gallery, inspecting for a blockage. Remove the rockers for cylinders one, two and three. Blow compressed shop air through the rocker arm inspecting for blockage. If no blockage is found, replace the Jake Brake rockers that did not have the pistons activate.

4374/0 UNDER PRESSURIZED DIESEL EXHAUST FLUID SYSTEM

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EPA07/10/GHG14 DDEC VI/10 Electronics and Troubleshooting Manual (DDC-SVC-MAN-0084) | 505 SPN 4374 (ACM) (GHG14) | 505.1 SPN 4374/FMI 0 – GHG14

Description This Code Sets When the Diesel Exhaust Fluid (DEF) Pump Speed is Higher than Normal For a Given DEF Pressure
Monitored Parameter DEF Pump Speed, DEF Pressure
Monitor Sequence None
Execution Frequency Continuous When Enabling Conditions Met
Typical Duration Continuous Until Resolved
Dash Lamps MIL, CEL
Engine Reaction Derate 25%
Verification SCR ADS Self-Check

Possible causes:

  • Restriction in the DEF line between the DEF tank and the DEF pump
  • Restriction in the DEF line between the DEF pump and the DEF dosing unit
  • Air in the DEF line between the DEF tank and the DEF pump
  • Restriction in the DEF pump
  • Failed DEF pump

Check as follows:

NOTICE:

Customers in colder climates where winter ambient air temperatures generally stay below -11° C (12°F) need to verify that the DEF is not frozen before troubleshooting this fault code.

    1. Connect DiagnosticLink® .

    1. Turn the ignition ON (key ON, engine OFF).

    1. Check for multiple codes. Are codes SPN 4334/FMI 3, 4, SPN 4375/FMI 3, 4, or SPN 3361/FMI 3, 4, 5 also present?
        1. Yes; diagnose and repair the other fault codes first. Verify repair.

      1. No; Go to step 4.

    1. Turn the ignition OFF.

    1. Inspect the DEF tank vent tube. Is there any blockage or restriction?
        1. Yes; clear the restricted vent tube. Go to step 6.

      1. No; Go to step 6.

    1. Using DEF test strip A0005850202, check for diesel fuel or oil contamination of the DEF fluid. Does the test strip indicate contamination?
        1. Yes; replace the following components and refill the system with new DEF:
          • DEF tank
          • DEF tank header
          • DEF supply line from the DEF tank to the DEF pump
          • DEF line from the DEF pump to the DEF dosing unit
          • DEF return line from the DEF dosing unit to the DEF tank
          • DEF pump
          • DEF dosing unit

      1. No; Go to step 7.

    1. Inspect the DEF line that runs from the DEF pump to the DEF dosing unit. Is the DEF line damaged, pinched, or kinked?
        1. Yes; replace the DEF line from the DEF pump to the DEF dosing unit.

      1. No; Go to step 8.

    1. Inspect the DEF line that runs from the DEF tank to the DEF pump. Is the DEF line damaged, pinched, or kinked?
        1. Yes; replace the DEF line from the DEF tank to the DEF pump.

      1. No; Go to step 9.

    1. Disconnect the DEF supply line at the dosing unit. Fill the graduated cylinder supplied in DEF test kit (P/N: W060589001900) with water. Place the end of the DEF line into the graduated cylinder as far as possible.
NOTE: Place the graduated cylinder in a secondary container to catch over flowing DEF fluid, making sure you still have clear sight of the end of the DEF line.

    1. Using DiagnosticLink, perform the Selective Catalyst Reduction Airless Dosing System (SCR ADS) Self-Check routine. When the service routine is running, visually inspect the DEF line for continuous air bubbles coming from the line and DEF flow.

    1. Were any bubbles coming from the DEF pump supply line indicating a crack in the DEF pump feed line?
        1. Yes; replace the DEF supply line from the DEF tank to the DEF pump. Verify repair.

      1. No; Go to step 12.
NOTICE:

The RS SUPPLY KIT contains all the necessary parts for steps 12-15.

    1. Using the DEF/Doser Kit , replace the DEF pump module filter. Go to step 13.

    1. Replace the DEF pump inlet screen. Go to step 14.

    1. Replace DEF Pressure Relief Valve (PRV).  Go to step 15.

    1. Replace DEF dosing unit inlet screen. Go to step 16.
NOTE: If air pressure is greater than 827 kPa (120 psi), use a pressure regulator.

    1. Prime pump with shop air. Using a rubber tipped air gun to seal around the DEF pump inlet fitting, apply clean regulated shop air to the DEF pump inlet fitting for three to five seconds.
      d140723a

    1. Connect all DEF lines and electrical connections. Go to step 18.

  1. Perform Selective Catalytic Reduction Airless Dosing System (SCR ADS) Self-Check Routine to prime the system. Did the SCR ADS test pass?
      1. Yes; clear the codes and release the vehicle.

    1. No; replace the DEF pump. 

3556/18 EPA10 DIESEL OXIDATION CATALYST OUTLET TEMPERATURE LOW

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EPA07/10/GHG14 DDEC VI/10 Electronics and Troubleshooting Manual (DDC-SVC-MAN-0084) | 372 SPN 3556 (ACM) (EPA10) | 372.2 SPN 3556/FMI 18 – EPA10

Description This code sets when the exhaust temperature does not increase above the modeled threshold when the low temp regeneration is enabled.
Monitored Parameter Diesel Oxidation Catalyst (DOC) outlet temperature sensor
Typical Enabling Conditions Low temperature regeneration enabled, 1100 to 2050 rpm, 50% to 100% engine load.
Monitor Sequence None
Execution Frequency Continuous When Enabling Conditions Met
Typical Duration 20 seconds
Dash Lamps MIL, CEL
Engine Reaction None
Verification Low Temp Regeneration

Check as follows:

    1. Connect DiagnosticLink® . Go to step 2.

    1. Turn the key ON (Key ON, Engine OFF). Go to step 3.

    1. Check for multiple codes. Are there DOC outlet temperature sensor stuck fault codes or DOC outlet temperature sensor circuit fault codes present?
        1. Yes; diagnose the other fault codes first. Verify repair.

      1. No; Go to step 4.

    1. Are there any Hydrocarbon (HC) doser low pressure fault codes present?
        1. Yes; diagnose HC doser low pressure fault codes first. Verify repair.

      1. No; Go to step 5.

    1. Perform the low temperature Aftertreatment Device (ATD) regeneration; Go to step 6.

    1. After the low temp ATD regeneration has run for 20 minutes, monitor the DOC outlet temperature sensor reading. Is the DOC outlet temperature sensor reading within 25°C (45°F) of the other exhaust temperature sensor readings?
        1. Yes; Go to step 7.

      1. No; replace the DOC outlet temperature sensor. Verify repair.

  1. Visually inspect the exhaust system for leaks. Are there exhaust leaks present?

      1. Yes; repair the exhaust leaks. Verify repair.

     

    1. No; replace the HC doser block. Verify repair.