Check for Open
Perform the following steps to check for open.
1. Disconnect the ECM vehicle harness connector and VSS connector.
2. Install a jumper wire between sockets A and B of the VSS harness connector.
3. Measure resistance between sockets E2 and E3 on the ECM vehicle harness connector.
See Figure 54-2.
[a] If the resistance measurement is less than or equal to 5 , refer to section 54.3.5.
[b] If the resistance measurement is greater than 5
or open, the VSS signal line #556 or
return line #557 is open. Repair open and refer to section 54.3.13.
ECM Vehicle Harness Connector
Check for Short to Ground
Perform the following steps to check for short to ground.
1. Turn ignition OFF.
2. Remove jumper wire.
3. Measure resistance between sockets E2 and E3 and a good ground. See Figure 54-3.
[a] If the resistance measurement is greater than 1,000
or open, refer to section 54.3.9.
All information subject to change without notice.
6SE497 9709 Copyright © 1997 DETROIT DIESEL CORPORATION