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2018 CX-9 Transmission Shifting Hard/Delayed Engagement - P07xx?

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Mike T. · rep 0 · May 25, 3:32 AM · 1 replies · solved · Question

Vehicle: 2018 Mazda CX-9 Signature

Hello forum,

I'm experiencing some concerning transmission issues with my 2018 Mazda CX-9 Signature, which has about 70,000 miles. Lately, I've noticed hard shifts, especially between 2nd and 3rd gear, and sometimes there's a noticeable delay when shifting into drive or reverse from park.

I haven't seen a Check Engine Light yet, but I'm worried it might come on soon with a transmission-related code (like a P07xx series). Has anyone else with a CX-9 experienced similar problems? What could be the potential causes, and what should I check before taking it to a dealership?

✓ Accepted solution

ClearTheCode Admin

ClearTheCode Team · rep 0 · May 25, 3:32 AM

0

ClearTheCode admin answer:

Transmission issues like hard shifts and delayed engagement in your 2018 Mazda CX-9 can be concerning. While a Check Engine Light (CEL) with a P07xx code (transmission specific) often appears, sometimes symptoms precede the code. Here's a breakdown of potential causes and initial checks:

Common Causes for Transmission Problems:

  1. Low or Contaminated Transmission Fluid: This is a very common cause. Low fluid can lead to poor hydraulic pressure, causing hard shifts or delays. Contaminated (burnt, dark) fluid indicates internal wear.
  2. Worn Solenoids: Transmission solenoids control fluid flow to various clutch packs. If they stick or fail, shifting can become erratic or harsh.
  3. Valve Body Issues: The valve body directs transmission fluid under pressure to operate the clutches and bands. Issues here can cause a range of shifting problems.
  4. Internal Wear: Worn clutch packs or bands within the transmission can lead to slipping or hard engagement.
  5. Transmission Control Module (TCM) Software: Sometimes, a software update for the TCM can resolve shifting anomalies.

Diagnostic Steps You Can Take:

  1. Check Transmission Fluid Level and Condition:
    • Consult your owner's manual for the correct procedure to check the transmission fluid level. Many modern Mazda transmissions are sealed, but some have a dipstick.
    • If there's a dipstick, check the fluid while the engine is warm and running (usually in Park or Neutral).
    • Note the color and smell. Healthy fluid is typically red or light brown and doesn't smell burnt. Dark, black, or burnt-smelling fluid is a sign of trouble.
  2. Listen for Abnormal Noises: Pay attention to any new grinding, whining, or clunking sounds coming from the transmission area.
  3. Note Driving Conditions: When do the hard shifts occur? Only when cold? Only under heavy acceleration? This information can be helpful for diagnosis.

When to See a Shop: Transmission problems are complex and often require specialized tools and expertise. It's highly recommended to take your CX-9 to a Mazda dealership or a reputable transmission specialist as soon as possible if:

  • You confirm the fluid is low or burnt, as this indicates a deeper issue.
  • The symptoms persist or worsen.
  • A Check Engine Light eventually illuminates. A professional shop can:
  • Scan for transmission-specific diagnostic trouble codes (DTCs) that your basic OBD-II scanner might miss.
  • Perform a thorough inspection of the transmission, including line pressure tests.
  • Diagnose internal component issues like solenoids or valve body problems.
  • Recommend appropriate repairs, which could range from a fluid flush and filter change to component replacement or a transmission rebuild. Ignoring these symptoms can lead to more severe and costly damage.
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