DIAGNOSTIC CODE 4-1, 4-2 OR 4-3

Test 13

Checking the voltage on the MPH PLUS (+) line

1.Disconnect the J1B and J2 connectors from the V-MAC II module.

2.Check for continuity between J1A connector pin H3 (the MPH sensor PLUS [+] line) and each of the other pins (one at a time) on the J1A, J1B and J2 connectors.

If there is a short, locate and repair the short in the harness. Retest to be sure the problem has been corrected.

If there is no short, proceed to Test 40.

Test 24

Checking the resistance in the harness

1.Turn the ignition key to the OFF position.

2.Disconnect the J1A and J1B connectors from the V-MAC II module.

3.Connect the serial link jumper into the serial communication port.

4.Measure the voltage from J1A connector pin H3 (the MPH sensor PLUS [+] line) to a good ground.

If the voltage is greater than zero volts, locate and repair the short to voltage in the harness. Retest to be sure the problem has been corrected.

If the voltage is not greater than zero volts, proceed to Test 26.

Test 20

Checking for continuity in the harness

1.Disconnect the jumper between harness connector pins A and B.

2.Reconnect the sensor.

3.Measure the resistance between J1A connector pins H3 (the MPH PLUS [+] line) and pin G3 (the MPH MINUS [ ] line).

If the resistance is less than 500 ohms, proceed to Test 48.

If there is no resistance, locate and repair the open in the sensor connector. Retest to be sure the problem has been corrected.

DIAGNOSTIC CODE 4-1, 4-2 OR 4-3

Test 25

Checking for an open in the MPH PLUS (+) line

1.Disconnect the jumper between harness connector pins A and B.

2.Disconnect the J1B connector from the V-MAC II module.

3.Connect a jumper between J1A connector pin H3 and J1B connector pin P2.

4.Check for continuity from harness connector pin A (the signal [+] line), on the harness end of the connector, to a good ground.

If there is continuity, repair the open in the MPH sensor MINUS [ ] line (pin G3) on the J1A connector. Retest to be sure the problem has been corrected

If there is no continuity, select another chassis ground. If there is still no continuity, repair the MPH PLUS [+] line (pin H3) on the J1A connector. Retest to be sure the problem has been corrected.