DDEC TROUBLESHOOTING
2. Ensure the air conditioning of the vehicle is OFF.
3. Run engine for at least three minutes.
4. Plug in DDR.
5. Select switch / light status.
6. Check the status of the Fan Control #1 while noting the actual fan status as
listed in Table 10-8.
Status
Status
Status
Status
Fan Control #1
ON
OFF
ON
OFF
Actual Fan State
OFF
ON
ON
OFF
Refer to section
10.8.3.
Refer to section
10.8.4.
Refer to section
10.8.6
Refer to section
10.8.7
Table 10-8
Troubleshooting Fan
10.8.3
Fan Information
The steps that led to this procedure do not indicate a problem with the fan control logic in the
ECM. The fan operation is normal if the steps that you checked led you to this section.
The fan status is correct according to what the ECM is requesting.
If you believe the fan state should be different, review the DDEC application and installation
manual for information on fan control configuration.
10.8.4
Check Input Status
Read the status of the inputs used for fan operation listed in Table 10-9. (Note both together.)
Status
Status
Status
Aux. Fan Control
OFF
ON
ON
Fan Override
OFF
ON
OFF
Refer to section 10.8.5
Refer to section 10.8.8
Refer to section 10.8.3
Table 10-9
Input Status
10.8.5
Check for Input Open
Perform the following steps to check for an open:
1. Turn ignition OFF.
2. Disconnect vehicle 30-pin connector at the ECM.
3. Turn ignition ON.
All information subject to change without notice.
6SE497 9709 Copyright © 1997 DETROIT DIESEL CORPORATION
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