How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Dan Your Own Question
Dan
Dan, ASE Certified Technician
Category: Mitsubishi
Satisfied Customers: 1650
Experience:  Auto Technician
94707146
Type Your Mitsubishi Question Here...
Dan is online now
A new question is answered every 9 seconds

2008 lancer. Non-awd. Code P0720. Just replaced the sensor

Customer Question

2008 lancer. Non-awd. Code P0720. Just replaced the sensor and code still there. I reset the code also. And it's still there.
Car revs fine but stops at 3500 in park, but when in drive or reverse or low it just revs up. No noises from transmission.
Submitted: 9 months ago.
Category: Mitsubishi
Customer: replied 9 months ago.
Expert:  Dan replied 9 months ago.

Hello my name is***** am an ASE Master Technician and I am glad to help you out with your question.

Expert:  Dan replied 9 months ago.

Do you need a wiring diagram or just want possible causes?

Customer: replied 9 months ago.
Possible causes and diagram
Customer: replied 9 months ago.
I know a bit about cars, I work on them a little bit. But can't seem to find the problem with this.
Expert:  Dan replied 9 months ago.

p0720

PROBABLE CAUSES

  • Malfunction of secondary pulley speed sensor
  • Damaged wiring harness and connectors
  • Malfunction of TCM
Customer: replied 9 months ago.
I've seen all that. I looked into it. How could I know if tcm is malfunctioned.
Expert:  Dan replied 9 months ago.

Diag flow chart

Expert:  Dan replied 9 months ago.

p0720

DIAGNOSTIC PROCEDURE

  1. STEP 1. M.U.T.-III data list

    Item 2: Secondary speed sensor signal (Refer to DATA LIST REFERENCE TABLE .)

    Q: Is the check result normal?

    YES : Intermittent malfunction

    NO : Go to Step 2.

  2. STEP 2. Check the following connector:
    • C-40 TCM connector
    • B-113 Secondary pulley speed sensor connector
    • A-10 Intermediate connector

    Check the terminals for a contact status problem and internal short circuit.

    Q: Is the check result normal?

    YES : Go to Step 3.

    NO : Repair the defective connector.

  3. STEP 3. Check for open circuit in the wiring harness between the secondary pulley speed sensor connector and the TCM connector .

    Between B-113 secondary pulley speed sensor connector (terminal No.3) and C-40 TCM connector (terminal No.48)

    Q: Is the check result normal?

    YES : Go to Step 4.

    NO : Repair the wiring harness.

  4. STEP 4. Check for open circuit and short to ground in the wiring harness between the secondary pulley speed sensor connector and the TCM connector

    Between B-113 secondary pulley speed sensor connector (terminal No.2) and C-40 TCM connector (terminal No.36)

    Q: Is the check result normal?

    YES : Go to Step 5.

    NO : Repair the wiring harness.

  5. STEP 5. Check for open circuit in the wiring harness between the CVT control relay and the secondary pulley speed sensor connector .

    Between A-15X CVT control relay (terminal No.3) and B-113 secondary pulley speed sensor connector (terminal No.1)

    Q: Is the check result normal?

    YES : Go to Step 6.

    NO : Repair the wiring harness.

  6. STEP 6. Secondary pulley speed sensor check

    Visually check the tip of the sensor for foreign materials or damage.

    Q: Is the check result normal?

    YES : Go to Step 7.

    NO : Repair.

  7. STEP 7. Diagnosis code recheck after replacing the secondary pulley speed sensor

    Q: Is the check result normal?

    YES : The inspection is complete.

    NO : Replace TCM.

Expert:  Dan replied 9 months ago.
Expert:  Dan replied 9 months ago.

Please reply to this if you need more help and we can continue this conversation. If you are satisfied with my service, please rate at the top of the screen. Rating does not close out your question. Remember, sometimes it is difficult to completely diagnose your vehicle without being there, but I will try to give you the best answer I can. If I am not giving you 5 star service, please let me know what I missed.

Thanks,

Dan

ASE Master Technician

Customer: replied 9 months ago.
I'm sorry I don't mean to be rude, please stop talking to me like your a robot. Lol and everything you provided I've already seen. I was wondering if you could help me with different suggestions.
Expert:  Dan replied 9 months ago.

I am giving you what you asked for. Have you gone through all of the diagnostic procedure? If you replaced the sensor already then the problem is in the tcm or wiring harness.

Expert:  Dan replied 9 months ago.

Have you checked the 20 amp fuse and the cvt relay?

Customer: replied 9 months ago.
I have no. Where would the cvt relay be and would that throw the code? How could I check if it's bad?
Customer: replied 9 months ago.
Have not*
Expert:  Dan replied 9 months ago.

Do you have a multi meter?

Customer: replied 9 months ago.
I do not. I've heard about putting a jumper wire in terminals. Would that work?
Expert:  Dan replied 9 months ago.

You really need a scan tool and a multi meter to properly diagnose this problem.

Customer: replied 9 months ago.
Picking them up today. I'll see what I can work with. I have an obd2 scanner
Customer: replied 9 months ago.
I'll go pick up a multimeter today
Expert:  Dan replied 9 months ago.

OK sounds good.

Customer: replied 9 months ago.
I printed of some wiring diagrams from Mitchell's at work. Got them. Gonna go pickup a multimeter after work. I'll let you know
Expert:  Dan replied 9 months ago.

ok

Customer: replied 9 months ago.
Got my multimeter ready. What should I check first.
Customer: replied 9 months ago.
Expert:  Dan replied 9 months ago.

Follow the diagnostic repair steps I sent you earlier for the p0720.

Customer: replied 9 months ago.
How do I know if there's signal. Ohms or just just volts?
Expert:  Dan replied 9 months ago.

You use ohms to check for open in the wiring harness. The actual signal is measured in Hz.

Customer: replied 9 months ago.
Use ohms and if it don't beep. There's a break?