DDEC IV TESTING
Check VPOD Wiring
The following checks should be performed for the VPOD wiring.
NOTE:
VPOD power should have been verified under the P/N check. If not, refer to
Check
Variable Output Pressure Device (VPOD) P/N and Supply Voltage.
.
1. Turn ignition switch ON.
2. Unplug the VPOD mating connector.
3. Insert a 1,000 ohm resistor between cavities #2 and #1 for the 12V version, or cavities
#2 and #3 for the 24V version.
4. Connect a VOM to the VPOD connector between pin #2 and pin #3 for the 12V VPOD
or pin #2 and pin #1 for the 24V VPOD.
5. Using a DDR/DDDL, activate the PWM #2 (EGR Valve) and PWM #4 (VNT), and ensure:
[a]
Activating 11 % duty cycle: VDC = 90% of the VPOD supply voltage ± 1 volt
(e.g. voltage to VPOD = 13.8V * 0.9 = 12.42V; therefore 11.42V to 13.42V at
PWM is okay.)
[b]
Activating 90 % duty cycle: VDC = 10% of the VPOD supply voltage ± 1 volt. (e.g.
voltage to VPOD = 13.8V * 0.1 = 1.38V, therefore 0.38V to 2.38V at PWM is okay.
6. Note any air leakage when PWMs are activated to 90% and correct the leaks as needed.
[a]
If both of the PWM voltage measurements are correct, replace the VPOD that had the
wrong pressure reading.
[b]
If the PWM voltage measurements are incorrect, and the wiring checks are okay, try
a test ECM programmed for EGR, or contact DDC Technical Service.
5-12
All information subject to change without notice.
(Rev. April 2004)
7SE60 0404
Copyright © 2004 DETROIT DIESEL CORPORATION