CM2150 Electronic Control System - 019-193 Exhaust Brake ON/OFF Switch

General Information
Resistance Check
Check for Short Circuit to Ground

General Information

TOC

The exhaust brake on/off switch circuit signals the system that the operator is requesting the exhaust brake system to be activated.		SMALL \| MEDIUM \| LARGE

After the ECM receives the signal from the exhaust brake on/off switch, the ECM will supply 12 VDC to the exhaust brake signal pin in the engine harness, provided the engine speed is not below 1000 rpm and the driver is not in cruise control or depressing the accelerator or clutch pedals.		SMALL \| MEDIUM \| LARGE

Resistance Check

TOC

If INSITE™ electronic service tool is available, monitor the exhaust brake select switch for proper operation. If
not, follow the troubleshooting procedures in this section.

Label the wires with the location on the switch or the wire number. Remove the electrical connectors from the switch.

SMALL | MEDIUM | LARGE

Set the multimeter to measure resistance.

Touch one multimeter probe to the center terminal of the switch. Touch the other multimeter probe to the bottom terminal of the switch.

SMALL | MEDIUM | LARGE

Set the switch to the OFF position.

The multimeter
must show an open circuit (100k ohms or more).

If the circuit is
not open, the switch has failed. Replace the switch.

Refer to the OEM repair manual for replacement instructions.

SMALL | MEDIUM | LARGE

Set the switch to the ON position.

The multimeter
must show a closed circuit (10 ohms or less).

If the circuit is
not closed, the switch has failed. Replace the switch.

Refer to the OEM troubleshooting and repair manual for replacement instructions.

SMALL | MEDIUM | LARGE

Check for Short Circuit to Ground

TOC

Touch one of the multimeter probes to one of the switch terminals. Touch the other probe to chassis ground. Move the switch to the ON position, and measure the resistance.

The multimeter
must show an open circuit (100k ohms or more).

If the circuit is
not open, the switch has failed. Replace the switch. Refer to the OEM troubleshooting and repair manual for replacement instructions.

If the switch passes all of the previous checks, the circuit
must be checked for open circuits, short circuits to ground, short circuits from pin to pin, and short circuits to an external voltage source.