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| Illustration 1 | g01185104 |
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Schematic of the Start Relay (Typical Example) | |
The possible causes of this diagnostic code are listed:
- Wire 306-GN(Green) is open.
- The relay has failed.
- The ECM has failed. This is unlikely.
This diagnostic code is recorded when the ECM reads the current of the relay circuit as being below normal range (open circuit).
Note: This procedure can cause new diagnostic codes to be recorded. Ignore these created diagnostic codes. Complete the following procedure. Then clear the created diagnostic codes.
System Response:
The start relay will NOT energize.
Test Step 1. CHECK THE RELAY.
- Turn the disconnect switch and the key start switch to the ON position. Do not start the engine. Ensure that the diagnostic code for the relay is active.
- Disconnect the machine harness from the relay.
- At the machine harness connector for the relay that is being tested, install a jumper wire. Install the jumper wire from contact 2 (306-GN(Green)) to contact 1 (200-BK(Black)).
- Observe the status of the diagnostic code. The diagnostic code is active or the diagnostic code is NOT active.
Expected Result:
The status of the diagnostic code is active and the status of the diagnostic code is NOT active as the jumper is installed and then removed.
Results:
- YES - The circuit is correct.
Repair: The relay has failed. Repeat the test step "CHECK THE RELAY" in order to verify that the relay has failed. Replace the relay.
STOP
- NO - The diagnostic code remains active. Proceed to test step 2.
Test Step 2. CHECK THE RELAY CIRCUIT FOR AN OPEN.
- The jumper that is between the signal wire and the return wire remains installed.
- Turn the key start switch and the disconnect switch to the OFF position.
- Disconnect the machine harness connector J2 from the ECM.
- At the J2 machine harness connector for the ECM, measure the resistance from contact J2-7 for the relay to frame ground.
Expected Result:
There should be continuity. The resistance measures approximately 40 ohms.
Results:
- YES - The machine harness is correct. Proceed to test step 3.
- NO - There is an open circuit in the machine harness.
Repair: The open circuit is in the signal wire (306-GN(Green)) or in the ground wire. Repair the machine harness or replace the machine harness.
STOP
Test Step 3. CHECK IF THE DIAGNOSTIC CODE REMAINS.
- The contacts of the harness connectors should be cleaned and the contacts of the harness connectors should be inspected.
- Reconnect all of the harness connectors.
- Turn the disconnect switch and the key start switch to the ON position.
- Clear all of the inactive diagnostic codes.
- Operate the machine.
- Stop the machine and place the parking brake switch in the ON position.
- Observe the status of the diagnostic code. The diagnostic code is active or the diagnostic code is NOT active.
Expected Result:
The diagnostic code is NO longer active.
Results:
- YES - The diagnostic code is NO longer active. The diagnostic code does not exist at this time. The initial diagnostic code was probably caused by a poor electrical connection or a short at one of the harness connectors that was disconnected and reconnected. Resume normal machine operation.
STOP
- NO - The diagnostic code has not been corrected. It is unlikely that the ECM has failed.
Repair: Exit this procedure and perform this diagnostic code again. Recheck the status of the diagnostic code. Replace the ECM if the cause is not found. See Testing and Adjusting , "Electronic Control Module (ECM) - Replace".
STOP