SPN 5542 FMI 15 CT11, CT13, CT15 Low-Pressure Turbo Outlet Pressure Too High/TC1TOP Above Desired {7000}
- On Highway Truck:
- CT660 (S/N: TGA1-UP; JFB1-UP; TJD1-UP; TEJ1-UP; TRK1-UP; TKL1-UP; TEM1-UP; TEP1-UP; TGR1-UP; TJS1-UP; TGS1-UP; TGT1-UP; TGW1-UP; TGD1-UP; TSW1-UP; TEY1-UP; TSY1-UP; TEZ1-UP; TGZ1-UP)
- CT680 (S/N: TWT1-UP; TKW1-UP; TRX1-UP; TRZ1-UP)
- CT681 (S/N: TWJ1-UP)
- CT680 (S/N: TWT1-UP; TKW1-UP; TRX1-UP; TRZ1-UP)
Introduction
This Special Instruction outlines the diagnostic procedure for Fault code SPN 5542 FMI 15 (Low-pressure turbo outlet pressure too high/TC1TOP above desired). Do not proceed to any diagnostic procedure with out first completely reading and understanding the outlines inside this Special Instruction.
Symptoms
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| Symptoms     | |
| DTC/Light     | Description     |
| SPN 5542 FMI 15     | TC1TOP above desired     |
| Malfunction Indicator Light (MIL) | |
Possible Causes:
- Restricted exhaust
- Stuck or sticking closed EBPV
- Failed ACV
Special Tools
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| Special Tools     | |
| Tool Description     | Tool Number     |
| Personal Computer (PC) with Engine Diagnostic Software     | N/A     |
| J1939 and J1708 RP1210B-Compliant Communication Device     | N/A     |
Diagnostic Procedure
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| Step     | Action     | Decision     |
| 1     | Check to see if the following faults are present in Electronic Control Module (ECM) (In addition to SPN 5542 FMI 15) : · Using PC with engine diagnostic software, check fault codes. · Look for SPN 5541,4452 (except FMI 15), and 5543. Are there any faults present?     | Yes: Diagnose these faults before SPN 5542 FMI 15     |
| No: Go to Step 2, Table 4 |
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| Step     | Action     | Decision     |
| 2     | Check for SPN 3719 Diesel Particulate Filter (DPF) soot load fault codes present in ECM: · Using PC with engine diagnostic software, check fault codes. · Look for SPN 3719 FMI 0 or 16(1) Is SPN 3719 present?     | Yes: Go to Symptom 2 of Troubleshooting, UENR5801, "CT11 and CT13 Non-SCR Aftertreatment System Diagnostics and Service Manual"     |
| No: Go to Step 3, Table 5 | ||
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| (1) | Excessive back pressure in the exhaust system, such as a plugged Diesel Oxidation Catalyst (DOC) and/or Diesel Particulate Filter (DPF) could set this fault. |
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 | |
| Illustration 1 | g03725876 |
EBPV in Open Position (Key OFF) (1) Air Inlet (2) Valve Should Be Fully Open with No Air Pressure (3) Resting Against Stop | |
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| Step     | Action     | Decision     |
| 3     | Inspect EBPV actuator: · Key OFF. · Inspect EBPV actuator and linkage. · Reference Illustration 1. Is the EBPV open (air cylinder NOT extended ) ?     | Yes, Open: Go to Step 5, Table 7.     |
| No, Closed or Partially Closed: Go to Step 4, Table 6 |
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| Step     | Action     | Decision     |
| 4     | If EBPV actuator is closed or partially closed: · Key OFF. · Remove air inlet line from EBPV actuator cylinder. · Reference Illustration 1.     | Yes: ACV has failed (air is being supplied to the EPBV with key OFF).     |
| Does air escape as air inlet connection is removed? | No: EPBV is stuck or seized. Replace EBPV assembly     |
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| Step     | Action     | Decision     |
| 5     | Check for physical damage and/or restriction to exhaust system: · Perform visual inspection of exhaust system.(2)     | Yes: Repair damage and/or restriction.     |
| No: Go to Step 6, Table 8 | ||
| Is the exhaust system damaged or restricted? |
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| (2) | Excessive back pressure in the exhaust system, such as a plugged Diesel Oxidation Catalyst (DOC) and/or Diesel Particulate Filter (DPF) could set this fault. |
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| Step     | Action     | Decision     |
| 6     | Perform EBPV actuator operation test: · Ensure air tanks have at least 621 kPa (90 psi) of pressure. Key ON. · Using PC with engine diagnostic software, go to Tests-KOEO Tests-Actuator Test-Select Exhaust Back Pressure Valve. · Command EBPV to 5% through 95% duty cycle while watching air cylinder actuator movement (95% fully extends the air cylinder shaft and closes the valve) .(3) Refer to Illustration 1.     | Yes: EBPV and ACV are working properly. An intermittent condition may exist or prior instructions were not followed.     |
| No: Go to Step 7, Table 9 | ||
| Does EBPV actuator move freely throughout its travel with no restrictions |
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| (3) | Test will command actuator ON for 5 seconds and then return actuator to the Closed position. |
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| Step     | Action     | Decision     |
| 7     | Perform EBPV actuator operation test (air system) : · Remove air line from EBPC at the air cylinder connection. · Using PC with engine diagnostic software, go to Tests-KOEO Tests-Actuator Test-Select Exhaust Back Pressure Valve. · Command EBPV to 95%.     | Yes: Check for failed air cylinder or stuck/seized EBPV. Replace if necessary.     |
| Does air flow out of the disconnected air line? | No: Go to Step 8, Table 10.     |
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| Step     | Action     | Decision     |
| 8     | Perform EBPV actuator operation test (air supply) : · Ensure air tanks have at least 621 kPa (90 psi) of pressure. · Loosen air supply line to ACV and verify if air escapes.     | Yes: ACV has failed.     |
| Does pressurized air escape? | No: Correct no air condition.     |
Parts Information
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| Part Number     | Description     | Qty     | Ordering     |
| 3862539-B10     | Engine harness connection - ACV pigtail kit     | 1     | Cat dealer     |
| 4190970     | ACV/Boost Control Solenoid Kit     | 1     | |
| 3762709     | EBPV/Brake Assembly, Exhaust     | 1     |
