S | Technical Service Bulletin

Technical Service Bulletin: TSB190003 Released Date: 10-Oct-2023
Engine Control Module (ECM) Malfunctions Due to Incorrect Switch Input Wiring

Engine Control Module (ECM) Malfunctions Due to
Incorrect Switch Input Wiring

Warranty Statement

The information in this document has no effect on present warranty coverage or repair practices, nor
does it authorize TRP or Campaign actions.

Contents

Product Affected

¢ B6.7 CM2350 B121B
¢ B6.7 CM2350 B135B
° B6.7 CM2350 B148B
¢ B6.7 CM2350 B136C
¢ B6.7 CM2350 B157C
¢ B6.7 CM2350 B198C
¢ B6.7 CM2450 B155B
¢ ISB6.7 CM2350 B101
e ISL9 CM2350 L101

¢ ISX12 CM2350 X102
¢ ISX15 CM2350 X101
e L9CM2350 L119B

e L9CM2350 L123B

« L9CM2450 L126B

¢ X12 CM2450 X137B

¢ X15 CM2350 X114B

¢ X15 CM2350 X116B

¢ X15 CM2450 X124B

« X15 CM2450 X134B

¢ X15 CM2350 X132C

Issue

Symptom:

« Engine control module (ECM) switch inputs, such as the power take-off (PTO)/Accelerator
Interlock/Oil pressure switch, are inoperable.

¢ Fault Codes 175, 176, and 415 (B6.7 Only).

¢ Fault Codes 5879 and 5881 (B, L9, X12 and X15 engines).

Root Cause:

e ECM switch inputs are wired incorrectly
e Malfunctioning OEM wiring harness

Confirmation
Perform the following steps to check and verify that the ECM switch inputs are wired correctly.

1. Remove the original equipment manufacturer (OEM) wiring harness connector from the ECM.
2. Use a multimeter to measure for voltage between pins 11, 12, 19, 20, 43, 44, 47, 66 through
70, 86 through 94, and ECM switch RETURN pin 62 at the OEM wiring harness connector.
© Specific pins used in the connector depend on what switches were installed by the
OEM.
3. Toggle the switch to ground inputs and check for battery voltage with the keyswitch in both the
ON and OFF positions.

Multimeter must show 0.0 volts. If any voltage is observed, the switch must be wired correctly
before the ECM is installed.

Reference the circuit diagram or wiring diagram for connector pin identification.
Use the following procedure for general multimeter usage techniques.

The resistance measurement given in this document of 0.020 Ohms is different than the Service
Manual specification.

Perform the following steps to check and verify that the ECM power return (ground) wires are
grounded correctly.

1. Disconnect the batteries. See equipment manufacturer service information.

2. Use a multimeter to measure the resistance between the OEM connector ECM ground return
pins and Battery (-) cable connection.

3. The multimeter ohm reading must be less than 0.020 Ohms. If reading is not less than 0.020
Ohms, the high resistance ground connection must be corrected.

4. Reconnect batteries. See equipment manufacturer service information.

5. With all components connected, use a multimeter to measure the voltage between the engine
ECM block ground stud and battery negative connection with the following conditions met in
order:

o Key off
© Key on; engine not running
o Key on; engine running and electrical accessories on

6. The multimeter must show less than 0.5VDC. If voltage is not less than 0.5VDC, the high

resistance ground connection must be corrected.