Detroit Diesel MBE 4000 DDEC VI Troubleshooting Manual page 283

27.5 SPN 103/FMI 7
Certain engines equipped with a turbo brake require turbo speed monitoring during the braking
mode in order to control engine brake power. The speed is controlled through the TSS installed
on the turbo shaft housing. SPN 103 (SPN 103/FMI 7) is logged when the MCM on the engine
fails to receive the monitoring signal from the sensor.
There are two possible causes for this fault code:
□ Failed sensor.
□ Sensor too close to the turbo shaft (not enough air gap).
27.5.1 Turbo Speed Sensor Check
Troubleshoot a Turbo No Revolution fault as follows:
1. With the engine stopped and at ambient temperature, unplug the TSS from the TSS
connector.
2. Measure the resistance between the sensor terminals.
[a] If resistance is approximately 900 Ω, refer to section 27.5.2.
[b] If resistance is zero or higher than 950 Ω, replace the sensor. Refer to section 27.5.2.1.
27.5.2 Adjust the Turbo Speed Sensor Air Gap
Adjust the TSS air gap a follows:
1. Remove the TSS from the turbo shaft housing.
2. Adjust the air gap by adding a 0.020 in. washer between the sensor body and the housing.
3. Install the sensor into the turbo shaft housing. Refer to section 27.5.2.1.
27.5.2.1 Verify Repairs
Verify repairs as follows:
1. Turn ignition OFF.
2. Reconnect any electrical connections that were disconnected to perform the diagnosis.
3. Clear codes with DDDL 7.0 or latest version.
4. Start and bring engine up to operating temperature (over 140°F/60°C).
5. Verify operation is satisfactory and no warning lamps illuminate. If warning lamps
illuminate, troubleshoot the codes. If assistance is required, call the Detroit Diesel
Customer Support Center at 313–592–5800.
All information subject to change without notice.
6SE568 Copyright © PRELIMINARY 2007 DETROIT DIESEL CORPORATION
(Rev. )
MBE 4000 DDEC VI TROUBLESHOOTING GUIDE
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