The Electronic Control Module (ECM) monitors the intake manifold air pressure. The following events are associated with low intake manifold air pressure:
Possible Causes
• Intake Air Filter
• Intake System
• Exhaust Gas Bypass Valve Regulator
• Low Battery Voltage
• Turbocharger
Suggested Actions
Note: The steps are listed below in order of probability. Perform these steps in sequence.
Troubleshooting and Repair Test Steps:
1. Intake Air Filter A. Check the air filter clogging indicator (if equipped).
B. Ensure the air filter is clean and usable.
Result: Air filter clogged. Repair:
Replace the air filter element.
Refer to the Operation and Maintenance Manual, “Engine Air Filter Element –
Replacement”. Result: Air filter normal.
Proceed to Test Step 2.
2. Intake System
A. Check the intake system for the following faults:
· Blockage
· Blockage
· Damage to intake pipes and hoses
· Loose connections and leaks
Result: The intake system is blocked, clogged, damaged, or loose.
Repair: Perform all necessary repairs to the intake system.
Result: The intake system is normal. Proceed to test step 3.
3. Exhaust Gas Bypass Valve Regulator
A. Use electronic repair tools to check for diagnostic codes related to the exhaust gas bypass valve regulator.
Result: Diagnostic codes related to the exhaust gas bypass valve regulator are present.
Repair: Eliminate the cause of any related codes. Please refer to Troubleshooting, “Diagnostic Codes”.
Result: No diagnostic codes related to the exhaust gas bypass valve regulator are present.
For engines with a single turbocharger, proceed to test step 4.
For engines with a twin turbocharger, proceed to test step 5.
4. Turbocharger Note:
The turbocharger installed on this engine is a non-repairable part. If any mechanical fault exists, the faulty turbocharger must be replaced.
A. Check the turbocharger compressor housing for dirt and debris.
B. Check the turbocharger turbine housing for dirt and debris.
C. Check that the turbocharger turbine blades can rotate freely.
Result: The turbocharger is faulty.
Repair: Replace the turbocharger. Please refer to Disassembly and Assembly, “Turbocharger – Removal” and Disassembly and Assembly, “Turbocharger – Installation”.
Result: The turbocharger is working properly.
Please contact the Dealer Solutions Network (DSN).
5. Turbocharger
Note: The turbocharger installed on this engine is a non-repairable item. If any mechanical fault exists, the faulty turbocharger must be replaced.
A. Inspect and confirm that the turbocharger compressor housing is free of dirt and debris.
B. Inspect and confirm that the turbocharger turbine housing is free of dirt and debris.
C. Inspect and confirm that the turbocharger turbine blades can rotate freely.
Result: The turbocharger is faulty.
Repair: Replace the faulty turbocharger. Please refer to Disassembly and Assembly, “Turbocharger – Removal” and Disassembly and Assembly, “Turbocharger – Installation”.
Result: The turbocharger is working properly.
Please contact the Dealer Solutions Network (DS)
