HOUSING 2340225 - Caterpillar

System Operation Description:The Engine Control Module (ECM) provides nine outputs that can be used to illuminate indicator lamps. The Caterpillar Electronic Technician (ET) can be used to program each output to a specific J1/P1 terminal. If applicable, some of the outputs can be programmed to a J1939 device.Each J1/P1 output is a high side driver or a low side driver.High Side Driver - The ECM provides an output voltage that is equal to the battery voltage in order to activate the lamp.Low Side Driver - The ECM provides a connection to ground in order to activate the lamp.J1939 Device - The ECM sends digital data on the J1939 data link in order to control the lamp.Table 1 provides information on the typical lamp outputs.
Table 1
Lamp Outputs (Typical Application)    
Lamp    Required
or
Optional    Programming Options    
Default Output Terminal Alternative
Output Terminal Programmable to a J1939 Device    
Diesel Particulate Filter Regeneration Disabled     Required     J1/P1:13     High Side Drivers
J1/P1:10, 11, 12, 13, 19, 20, 21
Low Side Drivers
J1/P1:28, 29, 30, 31
J1939 - Body Controller
J1939 - Cab Controller
J1939 - Instrument Cluster
J1939 - Cab Display     N/A    
PMS Warning Lamp     J1/P1:29
Diesel Particulate Filter     J1/P1:30
High Exhaust System Temperature     J1/P1:31
Check Engine Lamp     J1/P1:28
Red Stop Lamp     Optional     None    
Low Oil Pressure    
High Coolant Temperature    
Low Coolant Level    
Fast Idle    
PTO Switch On    
ARD Disable Lamp    
Illustration 1 g02154248
Illustration 2 g02476892
P1 terminals for the J1939 data linkTesting the CircuitsThe ECM briefly activates the following lamps when the keyswitch is turned from OFF to ON:
"Amber Warning Lamp"
"Red Stop Lamp"
"DPF Lamp"
"High Exhaust System Temperature Lamp"
"Aftertreatment Disable Lamp" (if equipped)Special tests on the Cat ET can activate every lamp except the check engine lamp. The special tests activate the lamps for all programming options.
Table 2
Troubleshooting Test Steps    Values    Results    
1. Test the Circuit
If the problem is related to one of the following lamps, turn the keyswitch from OFF to ON in order to test the circuit.
"Amber Warning Lamp"
"Red Stop Lamp"
"DPF Lamp"
"High Exhaust System Temperature Lamp"
"Aftertreatment Disable Lamp" (if equipped)
Otherwise, use the appropriate special test on Cat ET to test the circuit.
Watch the lamp during the test.
   
Circuit Test    
Result: Yes - The lamp does not illuminate.
Repair: Troubleshoot any active codes before continuing with this procedure.
Proceed to Test Step 2.
Result: No - The lamp illuminates.
Repair: There is a problem with the wiring if the problem is intermittent. Troubleshoot the wiring by referring to the electrical schematic.
   
2. Check the Bulb
A. Replace the bulb with a bulb that is known to be good. Test the circuit again.
   
Bulb    
Result: Yes - The lamp illuminates. The problem is resolved.
Result: No - The lamp does not illuminate. The bulb is OK.
The +Battery or the ground is not present at the lamp. Refer to the electrical schematic.
Troubleshoot the wiring by referring to the electrical schematic if the lamp output is programmed to a J1939 device.
Proceed to Test Step 3 if the lamp output is programmed