Neutral light turns on while driving

Welcome to 2CarPros.

When it indicates neutral, is it still in gear or does the engine rev like it is in neutral?

Take a look through this. It discusses the Check N range light.

2000 Mitsubishi Truck Montero Sport LS 4WD V6-3.0L SOHC
Check "N" Range Light
Vehicle Transmission and Drivetrain Automatic Transmission/Transaxle Testing and Inspection Reading and Clearing Diagnostic Trouble Codes Without Scan Tool Check "N" Range Light
CHECK "N" RANGE LIGHT
AUTOMATIC TRANSMISSION DIAGNOSTIC TROUBLE CODE DIAGNOSIS
CHECK "N" RANGE LIGHT

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The "N" range light flashes at a frequency of approximately 1 Hz (once per second) if there is an abnormality in any of the items in the table which are related to the A/T system. Check for diagnostic trouble codes if the "N" range light is flashing at a frequency of approximately 1 Hz.

"N" RANGE LIGHT FLASHING ITEMS

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CAUTION: If the "N" range light is flashing at a frequency of approximately 2 Hz (two flashes per second), it means that the automatic transmission fluid temperature is too high. Stop the vehicle in a safe place and wait until the "N" range light switches off.

ON-BOARD DIAGNOSTICS
The powertrain control module (PCM) monitors its input/output signals (some signals all time and others under specified conditions).
When an irregular signal is initially monitored, the PCM decides that a malfunction has occurred.
There are 27 diagnostic items. The diagnostic results can be read with a scan tool.
Diagnostic trouble codes are kept in memory by direct battery feed. The codes are retained in memory if the ignition switch is OFF
Diagnostic trouble codes will, however, be erased when a battery terminal or the PCM connector is disconnected. In addition, the diagnostic trouble code can also be erased by the scan tool MUT-II (MB991502).

NOTE: If a sensor is disconnected with the ignition switch is "ON, " a diagnostic trouble code is memorized. In this case, erase the DTC using the scan tool.

The 27 diagnostic items are all indicated sequentially from the smallest code number.

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I realize if you are not familiar with the jargon, it is very confusing. What needs done is the computer needs scanned to identify diagnostic trouble codes related to this problem. Once the code or codes are obtained, then we can focus on a specific component.

If you can, have the computer scanned and let me know what you find. Then we can do some pinpoint testing.

Let me know.

Joe

Welcome back:

The code you were told is for the engine coolant temperature sensor, so that doesn't fit this problem. Based on what you described and without extensive testing, I suspect it could be related to the A/T Control Relay. The relay is located on the passenger side behind the kick panel. See the attached picture.

What I suggest is to test that relay. The other things which can cause the N light to come on will require upper level diagnostic equipment that most people can't afford. At least I know I can't. lol

Here is a link that explains how to test a relay:

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

Here are a few links you may find helpful when testing the relay:

https://www.2carpros.com/articles/how-to-use-a-test-light-circuit-tester

https://www.2carpros.com/articles/how-to-use-a-voltmeter

https://www.2carpros.com/articles/how-to-check-wiring

I wanted to also add that it is possible that the scanner used to check for codes may not have been able to read transmission codes. You may want to ask.

Let me know if I can help of if you have other questions.

Take care,
Joe

Welcome back:

You are very welcome. If you get the chance, let me know what is found to be the issue.

Take care,

Joe

Welcome back:

Very possibly there is an issue with the transmission control module. If it stays in third, it could be in what is called limp mode. The term simply means the vehicle has a problem but will allow you to "limp" home or to safety. When it is stuck in third and you come to a stop, can you manually shift to low gear?

I also want to add that if there is a problem with the TCM, it should have set a diagnostic trouble code related to the transmission. Has anything changed with codes?

Let me know.

Joe

Welcome back:

You are very welcome. I will watch for your reply.

Joe

Welcome back:

It could do with the computer, but could also be related to a shift solenoid issue, transmission line pressure, transmission range sensor, and so on.

If shifting does not occur while driving and no diagnostic trouble codes are output, a malfunction of the Park/Neutral position switch, or PCM may exist.

The most likely causes for this case:
- Malfunction of Park/Neutral position switch
- Malfunction of pattern select switch
- Malfunction of the PCM

These are the most likely causes of what you described. Here are the directions for trouble shooting these things. The attached pics correlate with the directions. I realize you indicated no experience, so I don't know if you can actually perform these steps. It does require a scanner and some basic electrical testing components. I will add a few links after the diagnosis list you may find helpful.

I don't like adding things such as these directions because I don't want to confuse people more. I hope you understand, but more so, I hope it helps.

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DIAGNOSIS

STEP 1. Does the vehicle accelerate poorly (transmission stays in 3rd gear) when starting from a stop with the selector lever in "D" range?
If yes, go to Step 2.
If no, go to Step 6.

STEP 2. Check the backup power supply circuit.

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1. Disconnect harness connector C-90 and measure at the harness side.
2. Measure the voltage between terminal number 66 and ground.
- Voltage should be system voltage.
If not system voltage, go to Step 3.
If system voltage, go to Step 5.

STEP 3. Check the harness connector C-90 at the PCM for damage.

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If harness connector C-90 is damaged, repair or replace it. Refer to Harness Connector Inspection. Then check the symptom.
If harness connector C-90 is in good condition, go to Step 4.

STEP 4. Check the harness wire between PCM connector C-90 and fusible link.

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NOTE: After inspecting intermediate connectors A-54X, C-16, D-01 and D-14, inspect the wire. If intermediate connectors A-54X, C- 16, D-01 and D-14 are damaged, repair or replace them. Refer to Harness Connector Inspection.

If any harness wire between PCM connector C-90 and fusible link is damaged, repair it. Refer to Harness Connector Inspection. Then check the symptom.

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Required Special Tool: MB991502: Scan Tool (MUT-II)

CAUTION: To prevent damage to the scan tool MB9911502, turn the ignition switch "OFF" before connecting or disconnecting the scan tool MB991502.

STEP 5. Is A/T diagnostic trouble code number 54 output?
If yes, refer to Code number 54 - A/T control relay system. See: A L L Diagnostic Trouble Codes ( DTC ) > Manufacturer Code Charts > DTC 54
If no, go to Step 6.

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Required Special Tool: MB991502: Scan Tool (MUT-II)

CAUTION: To prevent damage to the scan tool MB991502, turn the ignition switch "OFF" before connecting or disconnecting the scan tool MB9911502.

STEP 6. Using scan tool MB991502, check data list item 61: Park/Neutral position switch.
- Scan tool should show the selector lever position.
If scan tool does not show correctly (Park/Neutral position switch is not operating properly), refer to Code number 27 or 28 - Park/Neutral position switch system. See: A L L Diagnostic Trouble Codes ( DTC ) > Manufacturer Code Charts > DTC 27
If scan tool shows correctly (Park/Neutral position switch is operating properly), go to Step 7.
Required Special Tool: MB991502: Scan Tool (MUT-II)

CAUTION: To prevent damage to scan tool MB991502, turn the ignition switch "OFF" before connecting or disconnecting scan tool MB991502.

STEP 7. Using scan tool MB991502, check data list item 62: Pattern select switch.

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- The scan tool should show the pattern select switch position.
If the scan tool does not show a correct position (pattern select switch is not operating properly), refer to Inspection procedure 17 - Pattern select switch system. See: Automatic Transmission/Transaxle > Symptom Related Diagnostic Procedures > Inspection Procedure 17
If the scan tool shows a correct position (pattern select switch is operating properly), check the symptom.
If the symptom is not eliminated, replace the PCM.

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Here are a few links you may find helpful.

https://www.2carpros.com/articles/how-to-use-a-test-light-circuit-tester

https://www.2carpros.com/articles/how-to-use-a-voltmeter

https://www.2carpros.com/articles/how-to-check-wiring

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Since it shows neutral when the problem happens, I suspect the problem is the park / neutral switch, but that is nothing more than an educated guess. What I would like you to try is checking it for adjustment. Here are the directions. Also, the remaining pics correlate with these directions.

2000 Mitsubishi Truck Montero Sport LS 4WD V6-3.0L SOHC
Adjustments
Vehicle Powertrain Management Sensors and Switches - Powertrain Management Sensors and Switches - Computers and Control Systems Transmission Position Sensor/Switch Adjustments
ADJUSTMENTS
PARK/NEUTRAL POSITION SWITCH AND CONTROL CABLE ADJUSTMENT

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1. Set the selector lever to the "N" position.
2. Loosen the control cable to manual control lever coupling nut to free the cable and lever.
3. Set the manual control lever to the neutral position.
4. Loosen the park/neutral position switch body mounting bolts and turn the park/neutral position switch body so the hole in the end of the manual control lever and the hole (cross section A-A in the figure on the left) in the flange of the park/neutral position switch body flange are aligned.
5. Tighten the park/neutral position switch body mounting bolts to the specified torque. Be careful at this time that the switch body does not move.
Tightening torque: 10 - 12 Nm (89 - 106 inch lbs.)
6. Gently pull the transmission control cable in the direction of the arrow, until the cable is taut. Tighten the adjusting nut.
Tightening torque: 24 Nm (18 ft. lbs.)
7. Check that the selector lever is in the "N" position.
8. Check that each position of the manual control lever matches each position of the selector lever.

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Please let me know if any of this helps or if you need help. I hope it is something as simple as the park / neutral switch adjustment. The switch is located on the side of the transmission. The shift cable will be attached to it.

Let me know.

Joe

Welcome back:

You are very welcome. I will watch for your reply. I'm interested in knowing if that is the problem.

Take care,
Joe