Troubleshooting Flash Code 17, Relative Humidity Sensor Circuit
The following procedure will troubleshoot Flash Code 17, relative humidity sensor circuit failed high.
Perform the following steps to check for codes:
- Start and run engine for 6 minutes.
- Plug in DDR and check for codes.
- If active code p 354/3 and any other codes are logged, troubleshoot the other codes first.
- If active code p 354/3 is logged, refer to "17.4.2 Check Connectors" .
- If no codes are logged, return the vehicle to service.
Perform these steps to check connectors:
Note: This sensor is wired via the 10–pin connector. See the wiring diagram; see Figure "Connectors" .
Figure 1. Connectors
- Check connectors for corrosion.
- Disconnect the connector at the RH sensor.
- Measure the resistance between cavities 2 and 3. See Figure
- If measured resistance is < 5 Ω, #976 is shorted to #416. Repair the short and test.
- If measured resistance is > 5 Ω, go to the next step.
Check for Open
Perform the following steps to check for open.
- Insert a jumper wire between cavity 2 and 1 of the RH sensor connector. See Figure "Connectors" .
- Unplug the engine side 30–pin connector.
- Measure the resistance between L2 and Y2.
- If measured resistance is < 5 Ω, replace the sensor and test.
- If measured resistance is > 5 Ω, either the signal return or #452 is open. Repair the open and test.
Perform the following steps to verify repairs.
- Plug in all connectors.
- Clear the codes.
- Start and run the engine.
- Operate at idle and rated speed.
- Turn ignition OFF.
- Plug in DDR and read the codes.
- If no codes are logged, troubleshooting is complete.
- If any codes are logged, review this section to find the error. Then, contact Detroit Diesel Technical Services.
|DDEC III/IV Single ECM Troubleshooting Guide - 6SE497|
|Generated on 10-13-2008|