10.13
FIRE TRUCK PRESSURE GOVERNOR FAULT
10.13.4 Check System Ground
Perform the following steps to check the system ground:
1. Start engine.
2. Turn ON pump control switch.
3. Verify all interlocks are set (parking brake, transmission neutral, etc.).
4. Plug in DDR. Select Switch/Light status.
5. Observe the displays and PGS ENABLE.
[a] If PGS ENABLE reads OFF, the PGS ENABLE input (circuit #543) is not grounded.
Check circuit #543 for an open between battery ground or a short to a voltage source.
Repair fault and retest. Refer to section 10.13.5.
[b] If PGS ENABLE reads ON, refer to section 10.13.7.
10.13.5 Check Sensor Wiring
Perform the following steps to identify the problem:
1. Compare pressure sensor harness wiring to the diagram.
[a] If the wiring is correct, refer to section 10.13.9. If the EFC tests okay,
refer to section 10.13.6.
[b] If the wiring is incorrect, correct the wiring and retest.
10.13.6 Verify Mode Selector Operation
Perform the following steps to identify the problem:
1. Start engine.
2. Turn ON pump control switch.
3. Verify all interlocks are set (parking brake, transmission neutral, etc.).
4. Plug in DDR. Select Switch/Light status.
5. Observe the displays and PGS MODE.
[a] If DDR displays ON when Pressure Mode is selected, the mode selector (circuit
#523) is functioning properly. Check for possible intermittent open or short to
voltage source. Check for faulty pressure transducer. Refer to section 10.13.5.
See Figure 10-10.
All information subject to change without notice.
10-54
6SE497 9709 Copyright © 1997 DETROIT DIESEL CORPORATION
