SPN 190 - FMI 2 (Diagnostic Code: Engine Speed Sensor - Erratic, Intermittent, or Incorrect)

Fracturing Transmission (TH55-E70)

Figure 1.1 - Engine Speed Sensor (190-2)

MID 027 CID 0190 FMI 02

#Condition which Generate this Code:

This Diagnostic Code is associated with the Engine Speed Sensor. This Diagnostic Code is recorded when the ECM reads the signal from the sensor and the ECM determines that the signal is erratic, intermittent, or incorrect.

The possible causes of this Diagnostic Code are listed:

• Wire (L912-WH/White) is shorted to the ground circuit while the machine is in operation.
• Wire (L912-WH/White) is shorted to the +Battery.
• An open circuit exists.
• The ECM has failed. This is unlikely.

Test Step 1. VERIFY THE SOFTWARE VERSION

→Check and record the latest software version for the machine electronic controls from SIS.

→Verify that the latest version of software has been loaded to the Transmission ECM.

Expected Result: All of the software is current.

Test Step 2. CHECK THE HARNESS.

A). Turn the key start switch to the OFF position.

B). Inspect the harness.

C). Check for the proper mating.

D). Check the exposed wires for nicks and abrasions.

E). Check for moisture, dirt, or corrosion.

F). Check the pin/socket for a proper fit.

G). Disconnect the machine harness connectors from the transmission ECM.

H). Place a jumper wire between contact 1 and contact 2 of the sensor.

I). Measure the resistance from connector contact J1-2 (wire L912-WH/White) to J1-3 (wire L913-OR/Orange) of the Transmission ECM.

Expected Result: The resistance should be less than 5 ohms.

Results:

→OK - The resistance is less than 5 ohms. The machine harness is correct. Proceed to test step 3.

→NOT OK - The resistance is greater than 5 ohms. There is an open in the machine harness.

→Repair: Repair the machine harness or replace the machine harness.

Test Step 3. CHECK IF THE DIAGNOSTIC CODE IS STILL ACTIVE.

A). Inspect the harness connectors. Clean the contacts of the harness connectors and check the wires for damage to the insulation that is caused by excessive heat, battery acid, or chafing.

B). Perform a 45 N (10 lb) pull test on each of the wires that are associated with the circuit.

C). Reconnect all harness connectors. Make sure that the connectors are fully seated and that the clips for each connector are completely fastened.

D). Turn the disconnect switch and the key start switch to the ON position.

E). Operate the machine.

F). Determine if the CID 0190 FMI 02 is active.

Figure 1.2 - Active Codes (190-2)

Expected Result: The CID 0190 FMI 02 is active.

Results:

→YES - The CID 0190 FMI 02 is active. The problem has not been corrected.

→Repair: Check the circuit again. If the Caterpillar Electronic Technician (Cat ET) is available, use the Cat ET service tool in order to perform a Wiggle Test on the machine wiring harness. The Wiggle Test can detect shorts and opens in the machine wiring harness that are momentary or intermittent. Read More: Wiggle Test on Caterpillar ET Software.

→It is unlikely that the ECM has failed. Exit this procedure and perform this procedure again. If the cause of the Diagnostic Code is not found, replace the ECM.

Figure 1.3 - Engine Speed (Abnormal Signal)

→NO - The CID 0190 FMI 02 is not active. The problem does not exist at this time.

→Repair: The initial Diagnostic Code was probably caused by a poor electrical connection or a short at one of the harness connectors that was disconnected and reconnected. Resume normal machine operation.

Test Step 4. REPLACE THE ENGINE SPEED SENSOR

→Replace the sensor with CAT P/N 318-1181.

Figure 1.4 - Engine Speed Sensor

Read More:

SPN 91 - FMI 8 (Diagnostic Code: Throttle Position Sensor Abnormal)

SPN 678 - FMI 4 (Diagnostic Code: 8 VDC Supply Voltage Below Normal)

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