Every generated code is stored in the memory of the module that detected the problem. The codes remain in the memory of the module even if power is removed from the module.
The diagnostic reset switch allows the operator to clear the diagnostic codes. Diagnostic codes cannot be individually cleared. Toggling the switch clears all of the diagnostic codes in all of the modules.
Note: Do not clear the diagnostic codes until all of the codes have been addressed.
If the engine is not equipped with the optional air/fuel ratio control, the EIS control module clears the codes. The codes are cleared when terminal "h" of the EIS connector is connected to ground.
If the input for clearing the codes is connected to ground for more than ten seconds, a 321-04 diagnostic code will be activated.
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| Illustration 1 | g01171944 |
Schematic diagram of the diagnostic reset switch The engine is equipped with a 70 pin connector and a EMCP II. | |
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| Illustration 2 | g01164628 |
Schematic diagram of the diagnostic reset switch The engine is equipped with a remote control panel. | |
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| Illustration 3 | g01171759 |
Schematic of the diagnostic reset switch The engine is equipped with a 70 pin connector. | |
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| Illustration 4 | g01164631 |
Schematic diagram of the diagnostic reset switch The engine is not equipped with a remote control panel. | |
Test Step 1. Inspect the Electrical Components and the Wiring
- Set the engine control to the OFF/RESET mode. Remove the electrical power from the engine.
Note: For the following steps, refer to Troubleshooting, "Inspecting Electrical Connectors".
- Thoroughly inspect each of the following components:
- EIS connectors
- The appropriate terminals on the terminal strips
- The electrical connections for the diagnostic reset switch
- The electrical connections for the idle/rated switch
- The electrical connections for the oxygen calibration switch
- Perform a 45 N (10 lb) pull test on each of the wires that are associated with the circuit for the diagnostic reset.
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Illustration 5 g01044800
Harness side of the EIS connector
(EISC-B) −Battery
(EISC-h) Diagnostic reset
- Check the wiring for corrosion, for abrasion, and for pinch points.
- EIS connectors
Expected Result:
The components and the wiring are connected properly. The connectors and the wiring do not have corrosion, abrasion, or pinch points.
Results:
- OK - The components are in good condition with proper connections. If you are troubleshooting a 321-04 diagnostic code, proceed to Test Step 2. If toggling the switch does not clear the codes, proceed to Test Step 3.
- Not OK - The components are not in good condition and/or at least one connection is improper.
Repair: Perform the necessary repairs and/or replace parts, if necessary.
STOP
Test Step 2. Check for a Short Circuit
- Disconnect the EIS connector.
- Measure the resistance between the points that are listed in Table 1.
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Table 1 Resistance Measurements for the Harness for the Diagnostic Reset Switch Terminals on the EIS Connector EISC-h (Input for the diagnostic reset) EISC-B (−Battery) EISC-L (Shutdown switch) EISC-Y (Ground for the left detonation sensor) EISC-Z (Ground for the speed/timing sensor) EISC-c (Return for the ignition transformer for cylinder 13) EISC-d (Ground for the right detonation sensor) EISC-n (Return for the ignition transformer for cylinder 1) EISC-p (Return for the ignition transformer for cylinder 3) Shell for the EIS connector
Expected Result:
Each check of the resistance is greater than 2 Ohms.
Results:
- OK - Each check of the resistance is greater than 2 Ohms. The input for the diagnostic reset is not shorted to ground. Proceed to Test Step 5.
- Not OK - At least one check of the resistance is less than 2 Ohms. There is a short circuit between ground and the input for the diagnostic reset.
Repair: Repair the connection and/or the wire, when possible. Replace parts, if necessary. Verify that the problem is resolved.
STOP
Test Step 3. Verify that all of the Problems are Repaired
- If toggling the switch does not clear the codes, the codes may still be active. Verify that every problem has been completely repaired.
Expected Result:
Every problem has been repaired.
Results:
- OK - All of the problems have been repaired. However, the diagnostic reset switch will not clear the codes. Proceed to Test Step 5.
- Not OK - All of the problems have not been repaired.
Repair: Correct the faults that are causing the codes. Return to this procedure, if necessary.
STOP
Test Step 4. Check for an Open Circuit
Note: Refer to the appropriate schematic diagram as you perform these steps:
- Measure the resistance between terminal h of the EIS connector and the appropriate terminal of the diagnostic reset switch. The expected resistance value is less than 2 Ohms.
- Measure the resistance between terminal B of the EIS connector and the appropriate terminal of the diagnostic reset switch. The expected resistance value is less than 2 Ohms.
Expected Result:
The resistance values are correct.
Results:
- OK - The resistance values are correct. The wiring for the diagnostic reset switch has continuity. Proceed to Test Step 5.
- Not OK - At least one of the resistance values is incorrect. The wiring for the diagnostic reset switch has an open circuit.
Repair: Repair the connection and/or the wire, when possible. Replace parts, if necessary. Verify that the original problem is resolved.
STOP
Test Step 5. Check the Diagnostic Reset Switch
Measure the resistance between the terminals of the diagnostic reset switch. Measure the resistance while the switch is not activated and while the switch is activated.
Expected Result:
When the switch is not activated, the switch is an open circuit. When the switch is activated, the resistance is less than 2 Ohms.
Results:
- OK - The readings are correct. The switch is operating correctly. Proceed to Test Step 6.
- Not OK - The readings are not correct.
Repair: Replace the diagnostic reset switch.
STOP
Test Step 6. Perform a Self Test of the EIS Control Module
- Perform the self test for the EIS control module. Refer to Troubleshooting, "Control Module Self Test".
Expected Result:
The self test was successful.
Results:
- OK - The self test was successful.
Repair: If the problem persists, refer to Troubleshooting, "Inspecting Electrical Connectors".
STOP
- Not OK - The self test was not successful.
Repair: Perform the corrective action that is appropriate for the fault. Refer to Troubleshooting, "Control Module Self Test". Verify that the original problem is resolved.
STOP