Test Step 5. Measure Vehicle Speed Sensor Resistance at the Sensor

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TM 9-2320-312-24-2

Troubleshooting Section

If the sensor is damaged, replace the damaged

Select the schematic that is similar to the circuit

sensor or send the vehicle to the OEM dealer for

that is being repaired.

repairs.

Expected Result:

Verify that any repair eliminates the problem.

RESULT 1 The vehicle speed circuit is similar to

Schematic 1, 2, or 3.

STOP.

Test Step 6. Inspect the Passive Magnetic

RESULT 2 The vehicle speed circuit is similar to

Speed Sensor for Vehicle Speed.

Schematic 4 or 5.

RESULT 3 The ECM is configured for the "J1939

A. Remove the vehicle speed sensor from the

Trans" option.

transmission and inspect the vehicle speed

sensor for steel shavings, debris, or damage.

Results:

Note: Shavings and debris on the sensor may

Result 1 Proceed to Test Step 5.

occur unless the transmission fluid is drained and

replaced according to the maintenance schedule.

Result 2 The vehicle speed circuit is similar to

Schematic 4 or 5. Proceed to Test Step 7.

B. Wipe off the sensor until the sensor is clean.

Test the sensor according to the manufacturer's

Result 3 Proceed to Test Step 9.

instructions. The sensor is OEM supplied.

Test Step 5. Measure Vehicle Speed

Note: If the gap between the vehicle speed sensor

Sensor Resistance at the Sensor.

and the chopper wheel is too small, the sensor

may be damaged. Also if the gap between the

A. Disconnect the vehicle speed sensor from the

vehicle speed sensor and the chopper wheel is too

vehicle harness.

small, the sensor may create a signal due to the

vibration of the chopper wheel. This will cause a

B. Thoroughly inspect the connector. Ensure that

vehicle speed signal when the vehicle is parked. If

the connector terminals are free of corrosion

the vehicle is parked and a vehicle speed signal is

and ensure that the connector terminals are fully

produced, back out the sensor from the wheel until

seated into the housing of the connector. Repair

the signal disappears. Use caution. backing out

the connector terminals or replace the connector

the sensor too far may cause a loss of the vehicle

terminals, as required.

speed signal. Back out the sensor no more than

one turn to one and one quarter turns.

C. Measure the resistance between the two

terminals of the sensor connector. The sensor

Expected Result:

resistance measurement should be 100 to 4500

Ohms.

The vehicle speed sensor is correctly installed and

undamaged.

D. Reverse the meter leads and measure the

resistance. Switching the probes should not

Results:

change the resistance measurement by more

OK Proceed to Test Step 7.

than 10 Ohms.

Not OK

Expected Result:

The sensor resistance that is measured is between

Repair: Perform the following repair:

100 and 4500 Ohms and the sensor resistance

that is measured is within 10 Ohms with the meter

If the sensor is damaged, replace the damaged

probes in either position.

sensor or send the vehicle to the OEM dealer for

repairs.

Results:

Verify that any repair eliminates the problem.

OK Reconnect the sensor to the vehicle

harness. Proceed to Test Step 6.

STOP.

Not OK

Repair: Perform the following repair: