| Diagnostic Codes Table | ||
|---|---|---|
| Code and Description | Conditions which Generate this Code | System Response |
| 623-5 Red Stop Lamp : Current Below Normal | While the output driver is off, the Electronic Control Module (ECM) detects an open in the circuit for the "Engine Fault" indicator for more than 5 seconds. | The code is logged. The alarm output is activated. |
| 623-6 Red Stop Lamp : Current Above Normal | While the output driver is activated, the ECM detects a short in the circuit for the "Engine Fault" indicator for more than 5 seconds. | The code is logged. The alarm output is activated. The output driver tries to activate the circuit component for 5 seconds. (1) |
| 624-5 Amber Warning Lamp : Current Below Normal | While the output driver is off, the ECM detects an open in the circuit for the "Action Alarm" indicator for more than 5 seconds. | The code is logged. |
| 624-6 Amber Warning Lamp : Current Above Normal | While the output driver is activated, the ECM detects a short in the circuit for the "Action Alarm" indicator for more than 5 seconds. | The code is logged. The alarm output is activated. The output driver tries to activate the circuit component for 5 seconds. (1) |
| 4244-5 Engine Run Relay : Current Below Normal | While the output driver is off, the ECM detects an open in the circuit for the engine running output for more than 5 seconds. | The code is logged. The alarm output is activated. |
| 4244-6 Engine Run Relay : Current Above Normal | While the output driver is activated, the ECM detects a short in the circuit for the engine running output for more than 5 seconds. | The code is logged. The alarm output is activated. The output driver tries to activate the circuit component for 5 seconds. (1) |
| 5273-5 Crank Terminate Relay : Current Below Normal | While the output driver is off, the ECM detects an open in the circuit for the crank terminate output for more than 5 seconds. | The code is logged. The alarm output is activated. |
| 5273-6 Crank Terminate Relay : Current Above Normal | While the output driver is activated, the ECM detects a short in the circuit for the crank terminate output for more than 5 seconds. | The code is logged. The alarm output is activated. The output driver tries to activate the circuit component for 5 seconds. (1) |
| ( 1 ) | This condition is latched. The ECM will attempt to power the circuit after the keyswitch has been cycled. |
The ECM has four outputs that are used to indicate the status of engine operation: action alarm output, crank terminate output, engine fault output and engine running output. These outputs are used to energize indicator lamps.
Action Alarm Output - This output is used to illuminate the amber warning lamp that is on the operator panel. The lamp indicates that there is an electrical problem or that there is abnormal operating condition with the engine.
Crank Terminate Output - This output is typically used to activate a lamp or a relay that is supplied by the customer. The output becomes active at the end of the crank cycle. When the engine is shut down, the output remains active until the engine speed drops below the crank terminate speed.
Engine Fault Output - This output is used to illuminate the red stop lamp that is on the operator panel. The lamp indicates that there is an electrical problem or that there is abnormal operating condition with the engine.
Engine Running Output - This output is used to illuminate the "Engine On" lamp that is on the operator panel. The output is used to indicate that the engine is in the run mode.
Note: Use Caterpillar Electronic Technician to view the current state of these outputs.
The ECM utilizes a low side ECM driver for each of these circuits. The ECM opens an internal circuit in order to turn off the output. The ECM closes the circuit in order to turn on the output. When the ECM activates the output, a maximum current of 0.3 a flows to an internal ground return circuit.
Note: Do not to overload the circuit for the crank terminate output. If a -6 code is being generated for this circuit, confirm that the customer component has a current draw of less than 0.3 a.
If excessive current flows through the circuit, a diagnostic code is generated. A short circuit to the +Battery side will also activate a diagnostic code.
Note: These circuits do not sink enough current for illumination of standard incandescent lamps. If a lamp is burned out, replace the lamp with the correct part number that is specified in the Parts Manual.
Note: The -5 code can only be detected by the ECM when the output for the low side driver is off. The -6 diagnostic code can only be detected by the ECM when the output for the low side ECM driver is on.
These codes may be generated as a shutdown condition or an alarm condition becomes active. Correct any adverse engine condition prior to troubleshooting these circuits. Failure to correct a serious condition with the engine can result in engine damage. Use Cat ET to determine if an event code or a diagnostic code that corresponds to the above codes is active. Troubleshoot other diagnostic trouble codes before you troubleshoot any of these diagnostic codes. Refer to Troubleshooting, "Diagnostic Trouble Codes" for the correct test procedure.
The following lists the most likely reasons for a diagnostic code related to the indicator lamps:
- A poor electrical connection
- A problem in a wiring harness
- Bulb
- The limiting resistor
- A thrown circuit breaker
The next likely cause is a problem with the lamp assembly.
Logged diagnostic codes provide a historical record. Before you begin this procedure, use Cat ET to save the logged codes to a file.
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| Illustration 1 | g01924194 |
Schematic for the indicator lamps | |
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| Illustration 2 | g01924767 |
Connector locations for the indicator lamp circuits (right side engine view) (1) P1 ECM connector (2) Connector for the interconnect harness | |
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| Illustration 3 | g01928463 |
Location of the circuit breaker at the breaker panel that is for the indicator lamps (3) 20 amp fuse for the indicator lamp battery power | |
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| Illustration 4 | g01924875 |
Location of the indicator lights that are at the remote panel (4) Red stop lamp (5) Amber warning lamp (6) Engine running indicator | |
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| Illustration 5 | g01925755 |
Terminal locations at the P1 ECM connector for the indicator lamps (P1-17) Engine fault output (P1-61) Crank terminate output (P1-63) Engine running output (P1-64) Action alarm output | |
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| Illustration 6 | g01926212 |
Terminal locations at the connector for the interconnect harness for the indicator lamps (Terminal C) Crank terminate output (Terminal H) Action alarm output (Terminal P) Engine fault output (Terminal Z) Engine running output (Terminal z) Battery power | |
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| Illustration 7 | g01926235 |
Terminal locations at the display panel terminal strip that is for the indicator lamps (Terminal 4) Action alarm output (Terminal 5) Engine fault output (Terminal 6) Engine running output (Terminal 13) Crank terminate output (Terminal 17) Battery power | |
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| Illustration 8 | g02015359 |
Indicator lamp (typical example) (7) Lamp assembly (8) Blade terminals (9) Resistor | |
| Troubleshooting Test Steps | Values | Results |
|---|---|---|
1. Inspect the Electrical Connectors and the Wiring A. Turn the main disconnect switch to the OFF position. B. Thoroughly inspect connectors (1) through (7) . Inspect all of the connectors that are associated with the circuit. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details. C. Perform a 45 N (10 lb) pull test on each of the wires in the ECM connectors that are associated with the circuit. D. Check the allen head screw for each of the ECM connectors for the proper torque. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details. E. Check the harness and wiring for abrasion and for pinch points from the sensors back to the ECM. |
Connectors |
Results: The harness and connectors appear to be OK. Proceed to Test Step 2 Results: There is a problem with the connectors and/or wiring. Repair: Repair the connectors or wiring and/or replace the connectors or wiring. Ensure that all of the seals are properly in place and ensure that the connectors are coupled. Verify that the repair eliminates the problem. |
2. Check for Battery Voltage at the Supply Wire for the Lamp Assembly A. Remove the battery voltage wire from the affected lamp assembly. B. Use a multimeter to check the voltage between the loose end of the wire and terminal 16 (-battery) of the display panel terminal strip. C. Reattach the blade terminal to the lamp assembly. |
Voltage |
Results: System voltage is available at the wire for the battery supply circuit at the affected indicator lamp. Proceed to Test Step 3. Results: Supply voltage is not available at the lamp assembly. Repair: There is a problem in the circuit between the batteries and the lamp assembly. Ensure that the 20 amp breaker is not tripped. Perform the necessary repairs. Verify that the repair eliminates the problem. |
3. Isolate the Circuit and Measure the Resistance of the Resistor A. Remove the resistor from the suspect lamp circuit. Note: Care must be taken while removing the resistor from the circuit. After the blade terminals have been disconnected, check that the blade terminals are securely crimped to the leads of the resistor. A poor electrical connection will result in premature failure of the lamp. B. Use a multimeter to check the resistance of the resistor. C. Restore the wiring to the original configuration. |
Resistance |
Results: The resistance of the resistor is within 1300 ± 65 Ohms. Proceed to Test Step 4. Results: The resistance of the resistor is not within 1300 ± 65 Ohms. Repair: There is a problem with the resistor. Replace the resistor. Verify that the repair eliminates the problem. |
4. Use a Jumper Wire to Check for Illumination of the Suspect Lamp A. Fabricate a jumper wire that is long enough to create a test circuit from the affected lamp to a good source of battery ground. Crimp a blade terminal (female connector) to one end of the jumper wire. B. Disconnect the control wiring that is for the ECM from the terminal at the lamp assembly. Connect the jumper wire to this terminal. Note: Ensure that the circuit for battery power remains attached to the terminal at the lamp assembly for this test. C. Connect the loose end of the jumper wire to a good source of battery ground. Check that the lamp is illuminated while the circuit is grounded. D. Restore the wiring to the original configuration. |
Illumination |
Results: The indicator lamp will illuminate while the jumper wire is attached between the lamp assembly and battery ground. The lamp assembly is in good repair. Proceed to Test Step 5. Results: The indicator lamp does not illuminate during the test. Repair: There is a problem with the lamp assembly. Replace the lamp assembly. Verify that the repair eliminates the problem. |
5. Check the Harness Wiring by Grounding the Circuit at the ECM Connector Note: If the lamp illuminates continuously, there is a short circuit to battery ground in the wiring between the ECM and the lamp assembly. Carefully inspect the harness for damage. A. Fabricate a jumper wire that is long enough to create a test circuit from the J1 ECM connector to a good source of battery ground. Crimp a connector pin to one end of the jumper wire. B. Disconnect the J1/P1 ECM connector from the ECM. Locate the wire that is for the suspect circuit at the P1 ECM connector. Insert the jumper wire into the correct socket for the suspect circuit. C. Connect the loose end of the jumper wire to a good source of battery ground. Check that the suspect lamp is illuminated while the circuit is grounded. D. Restore the wiring to the original configuration. |
Illumination |
Results: The indicator lamp will illuminate with the jumper wire is attached between the ECM terminal and battery ground. Repair: There does not appear to be a problem with the lamp assembly or the harness. The ECM is an unlikely cause of the problem. There may be an intermittent problem in the harness or in a connector. If you suspect that an intermittent problem exists in the harness or in a connector, refer to Testing and Adjusting, "Electrical Connectors - Inspect". If a problem with the ECM is suspected, check that the diagnostic code remains active. Perform this procedure again before considering the replacement of the ECM. Results: The indicator lamp does not illuminate during the test. Repair: There is a problem with the lamp assembly. Replace the lamp assembly. Verify that the repair eliminates the problem. |