DDEC TROUBLESHOOTING
10.13 FIRE TRUCK PRESSURE GOVERNOR FAULT
The following procedure will troubleshoot fire truck pressure governor fault.
10.13.1 Pressure Governor Operation
The Pressure Sensor Governor (PSG) System is a DDEC feature, programmed to allow the engine
speed to change in order to maintain a steady water pump pressure (pressure mode) or hold a
steady engine speed (RPM Mode).
10.13.2 Verify Correct Pressure Sensor Governor Configuration
Perform the following steps to verify the PSG configuration. Refer to the Application and
Installation manual for the appropriate engine model to ensure correct inputs and outputs are
configured. Required In / Outs are listed in Table 10-16.
1. Turn ignition ON.
2. Plug in DDR.
3. View H2 O governor enabled (engine configuration).
4. View In / Outs. Verify correct configuration.
[a] If the system is enabled and the in/outs are correctly configured,
refer to section 10.13.3.
[b] If the problem was found, correct the settings and retest. Refer to the DDEC III
Application And Installation manual, 7SA800 and refer to section 10.13.10.3.
Inputs
Outputs
PGS Mode, (Press / RPM)
PGS Active
PGS Enable
Cruise Active
Res / Accel
-
Set / Coast
-
Table 10-16
Required In / Outs
10.13.3 Identify Problem
Use the following procedure to identify the problem with the PSG:
Does not operate; refer to section 10.13.4.
No pressure mode, refer to section 10.13.6.
No increase function refer to section 10.13.7.
No decrease function refer to section 10.13.8.
EFC Fault Information refer to section 10.13.9.
All information subject to change without notice.
6SE497 9709 Copyright © 1997 DETROIT DIESEL CORPORATION
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