C7.1 Engines and Generator Sets Caterpillar

Intake Manifold Air Pressure Is Low

Usage:

C7.1 770

The Electronic Control Module (ECM) monitors the intake manifold air pressure. The following event is associated with low intake manifold air pressure:

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Table 1
Diagnostic Trouble Code for Low Intake Manifold Air Pressure
J1939 Code	CDL Code	Code Description (Code descriptions may vary)	Comments
102-18	E1045 (2)	Engine Intake Manifold #1 Pressure : Low - moderate severity (2)	This pressure is a variable value that is calculated by the ECM. The resulting value depends on the operating conditions of the engine.

Probable Causes

Intake air filter
Air intake system
Wastegate regulator
Low battery voltage
Turbochargers

Recommended Actions

Note: The procedures have been listed in order of probability. Complete the procedures in order.

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Table 2
Troubleshooting Test Steps	Values	Results
1. Intake Air Filter A. Check the air filter restriction indicator, if equipped. B. Ensure that the air filter is clean and serviceable.	Air filter	Result: The air filter is blocked. Repair: Replace the air filter element. Refer to the Operation and Maintenance Manual, "Engine Air Cleaner Element - Replace". Result: The air filter is OK. Proceed to Test Step 2.
2. Air Intake System A. Check the air intake system for the following defects: · Blockages · Restrictions · Damage to the air intake ducts and hoses · Loose connections and air leaks	Air intake	Result: The air intake system is blocked, restricted, damaged, or loose. Repair: Make all necessary repairs to the air intake system. Result: The air intake system is OK. Proceed to Test Step 3.
3. Wastegate Regulator A. Use the electronic service tool to check for diagnostic codes that relate to the wastegate regulator.	Wastegate regulator	Result: Diagnostic codes are present that relate to the wastegate regulator. Repair: Rectify the cause of any related codes. Refer to Troubleshooting, "Diagnostic Trouble Codes". Result: There are no diagnostic codes that relate to the wastegate regulator. Proceed to Test Step 4.
4. Low Battery Voltage Note: This possible cause of the fault is only applicable to 12 VDC systems. If the application operates with a 24 VDC system, proceed to Test Step 5. A. Use a suitable multimeter to check the output voltage from the battery or batteries.	Battery voltage	Result: The battery voltage is less than 9.75 VDC. Repair: The voltage requirement is not satisfied. Refer to Troubleshooting, "Battery Problem". Ensure that any repairs have eliminated the fault. Result: The battery voltage is OK. Proceed to Test Step 5.
5. Turbochargers Note: The turbochargers that are installed on the engine are nonserviceable items. If any mechanical fault exists, then the faulty turbocharger must be replaced. A. Check that the compressor housings for the turbochargers are free of dirt and debris. B. Check that the turbine housings for the turbochargers are free of dirt and debris. C. Check that the turbine blades rotate freely in the turbochargers.	Turbochargers	Result: There is a fault in a turbocharger. Repair: Replace the faulty turbocharger. Refer to Disassembly and Assembly, "Turbocharger - Remove" and Disassembly and Assembly, "Turbocharger - Install". Result: The turbochargers are OK. Contact the Dealer Solutions Network (DSN).