DDEC TROUBLESHOOTING
[c] If the voltage measurement is between 4 and 6 volts, refer to section 38.3.5.
Figure 38-3
Engine Harness Connector to Fuel Pressure Sensor
38.3.5
Check for Signal Open
Perform the following steps to check for signal open.
1. Turn vehicle ignition OFF.
2. Disconnect engine harness connector at the ECM.
3. Install a jumper wire between pins A and B of the FPS harness connector.
4. Measure resistance between sockets M1 and Y2 on the engine harness connector.
[a] If resistance measurement is less than or equal to 5
refer to section 38.3.10.
[b] If the resistance measurement is greater than 5
or open, the signal line (#905) or
return line (#452) is open. Repair the open and refer to section 38.3.12.
38.3.6
Check ECM Connectors
Perform the following steps to check the ECM connectors.
1. Check terminals at the ECM harness connector (both ECM and harness side) for damage:
bent, corroded, and unseated pins or sockets. Check W1, M1 and Y2 terminals at ECM.
[a] If terminals and connectors are damaged, repair them. Refer to section 38.3.12.
[b] If terminals and connectors are not damaged, install a test ECM.
Refer to section 38.3.12.
All information subject to change without notice.
6SE497 9709 Copyright © 1997 DETROIT DIESEL CORPORATION
38-7
