3516B and 3516C Engines For MT4400D AC Off-Highway Trucks Caterpillar

Intake Manifold Air Pressure Is Low

Usage:

Use this procedure in order to troubleshoot low intake manifold air pressure. Also, use this procedure if one of the following event codes is active.

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Table 1
Event Codes
Code and Description	Conditions which Generate this Code	System Response
102-18 Engine Intake Manifold #1 Pressure : Low - moderate severity (2)	The intake manifold air pressure is above the trip point for the programmed delay time.	The code is logged. The ECM may derate the engine or shutdown the engine.
E1045(2) Low Intake Manifold Pressure - moderate severity

Probable Causes

Diagnostic codes
Air inlet and exhaust restrictions
Condition of the turbochargers

Recommended Actions

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

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Table 2
Troubleshooting Test Step	Value	Result
1. Codes A. Establish communication between Caterpillar Electronic Technician (ET) and the Electronic Control Module (ECM). B. Monitor the diagnostic codes on Cat ET. Check for active or logged diagnostic codes. Specifically check for codes that could be associated to high intake pressure. Refer to the histogram information for engine derates in Cat ET. Note: Wait at least 30 seconds in order for diagnostic codes to become active. C. If the histograms contain derates and no diagnostic codes are present, then the engine is operating normally.	Codes	Result: A diagnostic code is present. Repair: Troubleshoot any codes before continuing with this procedure. Reset the histogram. Verify that the repair eliminated the problem. Result: A diagnostic code is not present. Proceed to Test Step 2.
2. Air Inlet and Exhaust Restrictions and/or Leaks A. Check the air filter for damage. If necessary, replace damaged air filters. Refer to the Operation and Maintenance Manual. B. Check the air inlet and exhaust system for restrictions and/or leaks. Make any necessary repairs. Refer to Systems Operation/Testing and Adjusting	Restriction and/or leaks	Result: The air filter and system are OK. Result: No leaks are present in the air inlet or exhaust systems. Proceed to Test Step 3. Result: The air filter and/or systems are NOT OK. Repair: Make the necessary repairs. Verify that the repair eliminated the problem.
3. Check the Condition of the Turbochargers A. Check the condition of the turbochargers.	Turbochargers	Result: The turbochargers are in good repair. Results: The turbochargers are damaged. Repair: Replace the turbocharger. Verify that the repair eliminated the problem.

If the procedure did not correct the issue, contact your Cat dealer Technical Communicator (TC). For further assistance, your TC can confer with the Dealer Solutions Network (DSN).