卡特C9发动机技术2

•24 Volt power supply

•Power supply components

•Power supply

diagnostic message

ECM Power Supply

The power supply to the ECM and the system is provided by the 24 V olt machine battery. The principle components in this circuit are:

- Battery

- Key Start Switch - Main Power Relay - 20 Amp Breaker - 20 Amp Fuse - Ground Bolt

- ECM Connector (P1/JI)

If the supply voltage exceeds 32.5 V olts or is less than 9.0 V olts, a diagnostic message is logged. (See the Troubleshooting Guide for complete details on voltage event logging.)

•ECM power supply circuit

•ECM switched connection

- Energizes ECM

•Battery disconnect switch The battery disconnect may be either on the positive or the negative cable depending on the application. The relevant Troubleshooting Guide will show the location of the switch.

The machine wiring harness can be bypassed for troubleshooting purposes. These steps are described in the Troubleshooting Guide procedure. A breakout harness can be used and is referenced under "C-9 Recommended Tooling" at the front of this book.

The supply voltage may be conveniently checked using the ET Status Screen display.

NOTE 1: The Challenger Tractor engine and some industrial engines may have a 12 V olt power supply.

NOTE 2:The Wire Function Color Code is shown here for the first time and is used through the presentation.

•P1/P2 70 pin ECM connectors

•P1/J1 machine

interface connector

There are two 70 pin connectors which identify the ADEM III ECM. The previous ADEM II ECM used a pair of 40 pin connectors.

The 70 pin ECM connectors are vital parts of all the power supplies (and sensor circuits). This illustration shows one of the two ECM 70 pin connectors, P1. The pins highlighted in this connector are for the ECM power supply circuit.

The C-9 Engine does not have a separate machine interface connector.The P1/J1 connector performs this function and transmits the power supply from the machine wiring to the engine wiring harnesses. The Troubleshooting Guide identifies the relevant pins for each circuit in this manner. This feature greatly simplifies troubleshooting by easily identifying the connections in the circuit.

•70 volt power supply

•Power supply wires are paired

•Injectors and brake solenoids are

switched on return side

Injector and Compression Brake Power Supply

The injector and compression brake solenoids are supplied with power from the ECM at 70 V olts. For this reason, precautions must be observed when performing maintenance around the valve covers.

If an open or a short circuit occurs in an injector or compression brake component, the ECM will disable that circuit. The ECM will periodically try to actuate that circuit to determine if the fault is still present and will disconnect or reconnect the injector/compression brake as appropriate.

The power supply wires are paired for each injector and brake solenoid.Individual return circuits are provided which contain the solenoid drivers. NOTE: If an injector is replaced, it must be calibrated. Also if an ECM is replaced and injector calibration or copy configuration is not performed, a fault message will be generated. (The Copy

Configuration function will transfer all calibrations to the new ECM.)