Exhaust Particulate Filter Circuit

271

TM 9-2320-312-24-2

Troubleshooting Section

No Verify that the switch for the exhaust brake

The diagnostic module provides a way to alert

the driver if the exhaust particulate filter becomes

is on and verify that the ET status screen reflects

plugged. The module monitors exhaust temperature

this condition. If the ECM is reading the switch

and exhaust back pressure. When the temperature

status change, temporarily connect a test ECM.

or the pressure reaches a predetermined level, the

Repeat this test step. If the problem is resolved

diagnostic module closes a switch that is connected

with the test ECM, reconnect the suspect ECM.

to the ECM at J1/P1:7 input 4 and J1/P1:18 input

If the problem returns with the suspect ECM,

sensor common 1. When the switch is closed the

replace the ECM.

ECM derates the engine and a warning light may be

illuminated. When the engine is derated, the engine

Repair: Perform the following repair:

speed is limited to 1200 rpm and the vehicle speed

is limited to 72 km/h (45 mph). Refer to System

1. Temporarily connect a test ECM.

Operation, Testing and Adjusting, RENR1271 and

Special Instruction, REHS1314, "Johnson Mathey

2. Remove all jumpers and replace all connectors.

CRTdm Interface Software Guide" if a problem is

suspected with the diagnostic module.

3. Recheck the system for active diagnostic

codes.

4. Repeat the test step.

5. If the problem is resolved with the test ECM,

reconnect the suspect ECM.

6. If the problem returns with the suspect ECM,

replace the ECM.

7. Verify that the repair eliminates the problem.

STOP.

g00890690

i01738942

Illustration 103

Exhaust Particulate Filter

Circuit schematic for the diagnostic module

Circuit - Test

SMCS Code: 1091-081

System Operation Description:

Use this procedure under the following situation:

Use this procedure to determine if the circuit for the

diagnostic module is operating correctly.

The following background information is related

to this procedure:

The ECM can use various inputs in a number

of ways. The inputs depend on the parameter

programming. Certain features are available on

several different inputs. When an exhaust particulate

filter is installed, the parameter "PTO Configuration"

is automatically programmed to "Cab Switches".

This parameter cannot be reprogrammed.

Diagnostic Module