0406-17

04 06-17
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04 06-17
SUBJECT
DATE
SPN 521221 (TCM)
April 2017
Additions, Revisions, or Updates
Publication Number / Title
DDC-SVC-MAN-0140
Platform
Section Title
Change
DT12
Transmissio
n
SPN 521221/FMI 19
This procedure has been rewritten.
DiagnosticLink users: Please update the troubleshooting guides in DiagnosticLink with this newest version. To update the
tool troubleshooting guide, open DiagnosticLink and from the Help – Troubleshooting Guides menu, select the appropriate
troubleshooting manual, then click Update.
All information subject to change without notice.
04 06-17
Copyright © 2017 DETROIT DIESEL CORPORATION
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2 SPN 521221/FMI 19
2
SPN 521221/FMI 19
No CAN Communication
Check as follows:
1. Are there any battery voltage faults (SPN 168/FMI any)?
a. Yes; troubleshoot battery voltage faults first.
b. No; Go to step 2.
2. Has the Transmission Control Module (TCM), Motor Control Module (MCM), Aftertreatment Control Module
(ACM), or Common Powertrain Controller (CPC) been recently reprogrammed?
a. Yes; clear the fault codes. If the fault does not become active, release vehicle. If fault becomes active, Go to
step 3.
b. No; clear the fault codes. If the fault does not become active, release vehicle. If fault becomes active, Go to step
3.
3. Disconnect the TCM X1 21-pin connector.
4. Inspect TCM X1 21-pin connector for corrosion, water intrusion or pin damage. Are there any damaged pins?
a. Yes; repair as necessary.
b. No; Go to step 5.
5. Turn the ignition ON (key ON, engine OFF).
6. Measure the voltage between TCM X1 21-pin connector pins 1, 2, 3, 4, 6 (ignition/battery voltage), and ground. Is the
voltage less than 11.5 volts?
a. Yes; restore voltage to TCM X1 21-pin connector pins 1, 2, 3, 4, and 6.
b. No; Go to step 7.
7. Turn the ignition OFF.
8. Measure the resistance between TCM X1 21-pin connector pins 16, 19, 20, 21, and the negative battery post. Is
resistance greater than three ohms?
a. Yes; restore battery ground to TCM X1 21-pin connector pins 16, 19, 20 and 21.
b. No; Go to step 9.
9. Measure the resistance between TCM X1 21-pin connector pins 10 and 11. Is the resistance between 55 and 65 ohms?
a. Yes; replace the Transmission Control Module (TCM).
b. No; repair Powertrain Controller Area Network (CAN) harness.
For GHG14; Refer to section "SPN 625/FMI 13 – GHG14" for further diagnostics.
For GHG17; Refer to section "SPN 625/FMI 13 – GHG17" for further diagnostics.
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All information subject to change without notice.
Copyright © 2017 DETROIT DIESEL CORPORATION 04 06-17