The indicator lamps are activated by the Electronic Control Module (ECM) in order to inform the operator of various engine events. The ECM provides five sinking outputs and the ECM provides one sourcing output. The outputs drive lamps and/or alarms which indicate diagnostic conditions. Alarm outputs are activated for five seconds when the ECM is powered up. This occurs for a self test of the alarm circuit.
The low oil pressure lamp indicates a low oil pressure condition. A low oil pressure condition is detected when the actual oil pressure is below a predetermined level.
The lamp for the low boost pressure indicates that the boost pressure is below a predetermined value.
The high coolant temperature lamp indicates a high coolant temperature condition. The diagnostic lamp indicates the presence of active diagnostic conditions. The lamp provides a diagnostic message in a series of flashes by the diagnostic lamp. The first sequence of flashes represents the first digit of a diagnostic flash code. The second sequence of flashes represent the second digit of the diagnostic flash code. This occurs after a two second pause. Additional codes will follow a two second pause. The additional codes will be displayed in the same manner.
The lamp for the derate for atmospheric pressure indicates a condition of low atmospheric pressure.
The low coolant level lamp illuminates when the coolant level is low.
Note: The ECM applies battery positive voltage in order to activate the low coolant level alarm.
The most likely cause of a problem with an indicator lamp is the bulb. The next most likely cause is a problem with a wire or with a connector. The least likely cause is a problem with the ECM.
Use this procedure to troubleshoot the indicator lamps or use this procedure if another procedure has directed you here. Before you perform this procedure, determine whether the bulb needs to be replaced.
 | |
| Illustration 1 | g01629094 |
 | |
| Illustration 2 | g01635773 |
(3) Low oil pressure (4) Diagnostic (5) Atmospheric derate (13) Low boost (14) Low coolant level (15) High coolant temperature | |
Test Step 1. Inspect Electrical Connectors and Wiring
- Turn the engine control switch to the OFF position.
- Thoroughly inspect the J14/P14 connector, and the lamp connections. Thoroughly inspect the J17/P17 connector. Refer to Troubleshooting, "Electrical Connectors - Inspect".
- Perform a 45 N (10 lb) pull test on each of the wires that are associated with the indicator lamps.
- Check the allen head screw on each ECM connector for the proper torque. Refer to service Troubleshooting, "Electrical Connectors - Inspect".
- Check the harness for abrasions and for pinch points from the battery to the ECM.
Expected Result:
All connectors, pins, and sockets are completely coupled and/or inserted. The harness and wiring are free of corrosion, of abrasion, and of pinch points.
Results:
- OK - All connectors, pins, and sockets are completely coupled and/or inserted. The harness and wiring are free of corrosion, of abrasion, and of pinch points. Proceed to Test Step 2.
- NOT OK - There is a problem in the connectors and/or wiring.
Repair: Repair the connectors or the harness and/or replace the connectors or the harness. Ensure that all of the seals are correctly in place and ensure that the connectors are completely coupled.Verify that the repair eliminates the problem.
STOP
Test Step 2. Check for Normal Operation of the Suspect Lamp
- Turn the engine control switch to the ON position and monitor the indicator lamps.
- The diagnostic lamps will illuminate for a minimum of two seconds after the power is returned to the ECM. The lamp will then turn off.
- Turn the engine control switch to the OFF position.
Note: A lamp may remain on if a diagnostic condition is present.
Expected Result:
The suspect lamp illuminates and the lamp turns off per the above description.
Results:
- OK - The suspect lamp illuminates and the lamp turns off per the above description.
Repair: The diagnostic lamps appear to operating correctly at this time. There may be an intermittent electrical problem in the harness or in a connector. If an intermittent problem is suspected, refer to Troubleshooting, "Electrical Connectors - Inspect".
STOP
- NOT OK - The suspect lamp does not illuminate or the suspect lamp does not turn off per the above description. Proceed to Test Step 3.
Test Step 3. Measure the Voltage at the Lamp Socket
- Turn the engine control switch to the ON position.
- Measure the voltage across each lamp socket. The measurement must be recorded within five seconds of turning the engine control switch to the ON position.
Expected Result:
The voltage is between 22.0 VDC and 27.0 VDC.
Results:
- OK - The voltage is between 22.0 VDC and 27.0 VDC.
Repair: Replace the bulb.Verify that the repair eliminates the problem.
STOP
- NOT OK - The voltage is not between 12.0 VDC and 24.0 VDC. Proceed to Test Step 4.
Test Step 4. Check the Voltage Supply and Engine Ground To The Lamps
- Turn the engine control switch to the ON position.
- Measure the voltage between the supply wires to the alarm lamps and engine ground.
- Turn the engine control switch to the OFF position.
- Measure the resistance between the negative wire for the low coolant level indicator and the engine ground.
Expected Result:
The voltage measures between 22 VDC and 27 VDC from the engine ground to the alarm lamps supply wires. The resistance between the negative wire of the low coolant level lamp and the engine ground measures less than 10 Ohms.
Results:
- OK - The voltage measures between 22 VDC and 27 VDC from the engine ground to the alarm lamps supply wires. The resistance between the negative wire of the low coolant level lamp and the engine ground measures less than 10 Ohms. Proceed to Test Step 5.
- NOT OK - The voltage measurement is not between 22 VDC and 27 VDC from the engine ground to the supply wires of the alarm lamps. The resistance between the negative wire of the low coolant level lamp and engine ground measures more than 10 Ohms.
Repair: There is a problem in the wiring harness or the connectors. Refer to Troubleshooting, "Electrical Connectors - Inspect".
STOP
Test Step 5. Check Battery Voltage to the ECM
- Turn the engine control switch to the ON position.
- Measure the voltage between connectorP14-1 and connector P14-21.
Expected Result:
The voltage is between 22 VDC and 27 VDC.
Results:
- OK - The voltage is between 22 VDC and 27 VDC. Proceed To Test Step 6.
- NOT OK - The voltage is not between 22 VDC and 27 VDC.
Repair: The ECM is not receiving the correct battery voltage. Refer to Troubleshooting, "Electrical Power Supply - Test".
STOP
Test Step 6. Bypass the ECM
- Turn the engine control switch to the OFF position.
- Disconnect ECM connector P14.
- Install Deutsch connectors on a 203 mm (8 inch) wire.
- Turn the engine control switch to the ON position.
- Connect the wire between the following locations:
- P14-21 and P14-3 (low oil pressure lamp)
- P14-21 and P14-4 (diagnostic lamp)
- P14-21 and P14-5 (derate for atmospheric pressure)
- P14-21 and P14-13 (low boost pressure)
- P14-21 and P14-15 (high coolant temperature lamp)
- P14-1 and P14-14 (low coolant level lamp)
- P14-21 and P14-3 (low oil pressure lamp)
Expected Result:
Each lamp illuminates when the jumper wire is installed.
Results:
- OK - Each lamp illuminates when the jumper wire is installed.
Repair: The harness and the lamps are working properly. Reconnect all of the connectors. Repeat the self test of the alarm circuit. If the problem still exists replace the ECM. Refer to Troubleshooting, "ECM - Replace".
STOP
- NOT OK - A lamp does not illuminate when the jumper is installed.
Repair: There is a problem in the wiring harness or the connectors. Refer to Troubleshooting, "Electrical Connectors - Inspect".
STOP