DDEC TROUBLESHOOTING
22.3.6
Check Throttle Position Sensor Connectors
Perform the following steps to check the TPS connectors:
1. Check terminals at the TPS connector (both sensor and harness side) for bent, corroded,
and unseated pins or sockets.
[a] If the terminals or the connectors are damaged, repair them. Refer to section 22.3.15.
[b] If the terminals and connectors are not damaged, replace the TPS and
refer to section 22.3.15.
22.3.7
Check for +5 Volts
Perform the following steps to check for +5 volts:
1. Remove jumper wire.
2. Turn ignition ON.
3. Measure voltage on TPS harness connector, socket C (5V supply #916) (red lead) to
socket A (return #952) (black lead).
[a] If measured voltage is greater than 6 volts, refer to section 22.3.13.
[b] If measured voltage is less than 4 volts, refer to section 22.3.11.
[c] If measured voltage is between 4 and 6 volts, refer to section 22.3.8.
22.3.8
Check for Short
Perform the following steps to check for a short:
1. Turn ignition OFF.
2. Disconnect the vehicle harness connector at the ECM.
3. Measure resistance between sockets A (return #952) and B (signal #417) at the TPS
harness connector. See Figure 22-3.
4. Measure resistance between socket B (signal #417) and a good ground (battery ground
and chassis ground).
[a] If resistance measurement is less than or equal to 100 , the signal line #417 is shorted
to the return line #952 or battery ground. Repair short. Refer to section 22.3.15.
All information subject to change without notice.
6SE497 9709 Copyright © 1997 DETROIT DIESEL CORPORATION
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