DDEC TROUBLESHOOTING
34.3.5
Check for Signal Open
Perform the following steps to check for signal open.
1. Turn vehicle ignition OFF.
2. Disconnect the engine harness connector at the ECM.
3. Install a jumper wire between pins A and B of the TBS harness connector. See Figure 34-3.
4. Measure resistance between sockets P1 and Y2 on the engine harness connector.
[a] If the resistance measurement is less than or equal to 5 , refer to section 34.3.6.
[b] If the resistance measurement is greater than 5 , or open, and the signal line (#432)
is open, repair the open. Refer to section 34.3.11.
Figure 34-3
Turbo Boost Sensor Schematic
34.3.6
Check for Short
Perform the following steps to check for short.
1. Remove jumper.
2. Measure resistance between pins A and B on the TBS harness connector.
[a] If measured resistance between pins A and B is greater than 100 , or open, go
to step 3
[b] If measured resistance between pins A and B is less than 100 , the signal line (#432)
is shorted to the return line (#452). Repair the short. Refer to section 34.3.11.
All information subject to change without notice.
6SE497 9709 Copyright © 1997 DETROIT DIESEL CORPORATION
34-7
