AEL03 Electronic Control Unit (ECU)

Most ECUs used in CAT electronic control systems use what three types of inputs?

Switch, analog and digital

What does an ECU require to operate correctly on an engine or machine system

Unswitched power and ground from the battery and keyswitch power, Data link, Flash file and Configuration and monitoring system parameters

Caterpillar uses what types of data links

CAT Data Link (no longer installed on some products)

CAN Data Link ( SAE J1939)

ATA Data Link (Used on some CAT Engines

Ethernet (increased use on newer products)

What are some typical reasons to flash a new file to an ECU?

Unswitched power and ground from the battery and keyswitch power, Data link, Flash file and Configuration and monitoring system parameters

When testing A4 and A5 ECUs what is the purpose of cycling the key start switch?

Allows key switch overrides to expire, which allows drivers to be reset

When testing an ECU, why is it important to remember to isolate the ECU from the harness?

A fault within a sensor or the harness can affect voltage readings at the ECU.

How can an ECU digital speed input be tested?

Measure the frequency with a DMM and compare to the specified frequency range of the sensor being used.

If an analog input has an open circuit condition, an activie ____ diagnostic code will be present

FMI-03 Voltage Above Normal

To test an ECU switch Input, what must be created to simulate the switch being actuated

Open and Short to Ground condtions

If an ECU detects a PWM input duty cycle below 5% or above 95%, what code will become active?

FMI-08 Abnormal Frequency Period or Pulse Width

What are common applications for MAC ECUs?

Implement System + Power Train

When connecting a laptop with CAT ET software, CAT ET will automatically show the ________ ECU as the Transmission ECU

ABL

What does the E in A5;E4 indicate

The ECU is an Engine Control

Identify the application for each of the following ECU types: ADEM, MAC and ABL

ADEM = Engine

MAC = Machine Systems

ABL = Machine Systems

What is the purpose of the CAT ET Injector Solenoid Test

The test actuates each injector solenoid and identifies if the circuit is OK, Shorted, or open

What is the purpose of the CAT ET Override Parameters Test?

Allows the available outputs to be activated. Once the output is activated, verify the ECU is outputting the correct voltage, and that the output is working (relay clicks, solenoid actuates, etc.).