DDEC TROUBLESHOOTING
[c] If the voltage measurement is between 4 and 6 volts, refer to section 36.3.5.
36.3.5
Check for Signal Open
Perform the following steps to check for signal open.
1. Turn the ignition OFF.
2. Disconnect the engine harness connector at the ECM. See Figure 36-3.
3. Install a jumper wire between sockets A and B of the OPS harness connector.
4. Measure resistance between sockets P2 and Y2 on the engine harness connectors.
[a] If the resistance measurement is less than or equal to 5 , refer to section 36.3.11.
[b] If the resistance measurement is greater than 5
or open, the signal line (#530) is
open. Repair the open and refer to section 36.3.12.
Figure 36-3
Engine Harness Connector to Oil Pressure Sensor
36.3.6
Check for Short
Perform the following steps to check for a short.
1. Remove jumper wire.
2. Measure resistance between socket P2 and a good ground. Also measure resistance
between P2 and Y2.
[a] If both resistance measurements are greater than 100
or open, replace OPS.
Refer to section 36.3.12.
All information subject to change without notice.
6SE497 9709 Copyright © 1997 DETROIT DIESEL CORPORATION
36-7
