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| Illustration 1 | g00664509 |
For a Timing Control Module (TCM) with software before September 1998, the TCM has not detected any ignition pulses when the engine speed is between 120 and 300 rpm. The source of the fault is one of the following conditions:
- Pin G of the magneto is grounded.
- There is an open circuit between the -battery and pin H of the Magneto Interface Box (MIB).
- The ground strap for the MIB is not connected properly.
- There is a open circuit or a short circuit condition in the wiring harness between the MIB and the TCM.
- The magneto is not electrically connected to the MIB.
- The magneto has failed.
- The MIB has failed.
For a TCM with September 1998 software or more recent software, the TCM has detected noise at any speed. The noise resembles many ignition pulses in a short period of time. The source of the fault is one of the following conditions:
- There is an intermittent connection between the magneto and the MIB.
- There is an intermittent connection between the MIB and the TCM.
- There is an intermittent connection or a connection with high resistance between the -battery and pin H of the MIB.
- The magneto shutoff relay in the status control module has failed.
- Pin G is intermittently connected to ground.
- There is a loose connection at pin B for the MIB .
- The ground strap for the MIB is not properly connected.
- The magneto has failed.
- The MIB has failed.
System Response:
The TCM will signal for an engine shutdown. The TCM will activate the outputs for the shutdown and the remote indicator. The "NO MAGNETO INTERFACE SIGNAL" LED will illuminate. The code may be viewed on the DDT.
Test Step 1. Perform the following test: Magneto Interface Signal
Results:
- OK - Stop.