TM-9-2320-272-24-2

TRUCK, 5-TON, 6X6, M939, M939A1, AND M939A2 SERIES TRUCKS (DIESEL)

TECHNICAL MANUAL; UNIT, DIRECT SUPPORT, AND GENERAL SUPPORT MAINTENANCE MANUAL; VOLUME 2 OF 4

JUNE 1998

TM-9-2320-272-24-2 - Page 674 of 991

TM 9-2320-272-24-2

3-468. ELECTRONIC CONTROL UNIT (ECU) REPLACEMENT

THIS TASK COVERS:

a. Removal

b. Installation

INITIAL SETUP:

APPLICABLE MODELS

M939A2

TOOLS

REFERENCES (TM)

TM 9-2320-272-10

TM 9-2320-272-24P

General mechanic’s tool kit (Appendix E, Item 1)

EQUIPMENT CONDITION

l

Parking brake set (TM 9-2320-272-10).

l

Battery ground cables disconnected (para. 3-126).

CAUTION

Use extreme care when handling ECU. Failure to do so may result

in damage to internal components.

a. Removal

1.

Disconnect CTIS wiring harness connector (1) from ECU receptacle (5).

2.

Remove three screws (3) and ECU (4) from transmission shifter tower (2).

b. Installation

1.

Install ECU (4) on transmission shifter tower (2) with three screws (3).

2.

Connect CTIS wiring harness connector (1) to ECU receptacle (5).

FOLLOW-ON TASKS:

l

Connect battery ground cables (para. 3-126).

l

Start engine (TM 9-2320-272-10) and check CTIS for proper operation.

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