What is Caterpillar Fault Code CID3587?

CID3587 indicates an Abnormal Update Rate on the Engine Control Module (ECM) datalink, specifically related to communication failures between the ECM and other machine control systems. This Component Identifier (CID) fault triggers when the ECM detects irregular or missing data packets from networked controllers on the CAN bus (Controller Area Network).

In Caterpillar excavators, the ECM constantly communicates with systems like the hydraulic controller, display monitor, and aftertreatment modules via the CAN datalink. When message update rates fall outside expected parameters—typically due to network disruptions—the system logs CID3587 to protect machine integrity. This fault is critical because erratic communication can cause unexpected machine behavior, reduced performance, or activation of derate modes that limit engine power to prevent potential damage.

Common Symptoms

Operators and technicians may observe the following when CID3587 is active:

• Warning lights illuminated on the instrument cluster, often accompanied by diagnostic lamp activation
• Intermittent or complete loss of display monitor functionality, including gauge readings and system status
• Engine derate or power reduction mode engaging unexpectedly during operation
• Hydraulic system irregularities, such as sluggish response or erratic function cycling
• Communication errors displayed on Cat Electronic Technician (ET) diagnostic software during active sessions

Potential Causes

CID3587 typically results from datalink integrity issues common in used equipment:

• Damaged or corroded CAN bus wiring harness, particularly at flex points near the engine or boom pivot areas where repeated movement causes insulation wear
• Loose or corroded connector pins at ECM, display monitor, or intermediate harness junctions—extremely common in machines exposed to moisture or mud
• Failed termination resistors on the CAN network endpoints, causing signal reflection and data corruption
• ECM internal communication circuit failure, though less common than harness issues in used machines
• Voltage irregularities from failing batteries or charging system problems affecting network signal quality
• Aftermarket component integration that improperly loads or interferes with the CAN bus datalink

How to Troubleshoot and Fix Code CID3587

Step 1: Visual Inspection of Harness and Connectors Begin by thoroughly inspecting all CAN bus harness routing from the ECM to connected modules. On used excavators, focus on areas where harnesses pass through bulkheads, near rotating components, or contact metal surfaces. Look for chafing, cracking, or exposed wires. Disconnect and inspect all relevant connectors for corrosion, bent pins, or moisture intrusion—clean with electrical contact cleaner and apply dielectric grease.

Step 2: Resistance and Continuity Testing Using a digital multimeter, measure CAN High and CAN Low circuit continuity and resistance. With all modules disconnected, check for approximately 60 ohms resistance between CAN High and CAN Low, indicating proper termination resistor function. Test each wire individually for shorts to ground or power, which commonly occur at harness wear points.

Step 3: Diagnostic Software Analysis Connect Cat Electronic Technician (ET) software and monitor live datalink traffic while wiggling suspect harness sections. Watch for communication dropouts or error count increases that correlate with harness movement. Check voltage levels on the CAN network—should read approximately 2.5V baseline with fluctuations during communication. Verify all networked modules are responding and logging appropriate identifiers.

Step 4: Component-Level Diagnosis If harness integrity tests pass, systematically disconnect non-essential CAN devices to isolate a potentially faulty module creating network interference. For used machines with previous repairs, verify any aftermarket displays or monitoring systems include proper isolation and don't overload the bus. Test battery voltage under load—low voltage (below 12V) can cause communication instabilities.

Disclaimer: This guide provides general troubleshooting direction for CID3587. Always consult official Caterpillar service documentation and consider professional diagnostic assistance, especially for complex datalink issues. Improper testing procedures can damage sensitive electronic modules.