Introduction to the trouble diagnosis of transmission, transaxle (AWR6B45)

1. Introduction to the trouble diagnosis of transmission, transaxle

1. Check trans warning light

The check trans warning light flashes when a DTC is set due to a failure affecting vehicle performance.

2. Improper vehicle maintenance

If the vehicle is not properly maintained, the check trans warning light may flash.
Vehicle maintenance schedules must be closely followed.

3. Non-OEM parts

All systems are adjusted to operate with genuine parts. Therefore, if a general aftermarket sensor or switch, etc., is installed, it may make a false diagnosis.
Aftermarket electronic equipment, such as mobile phones, stereos, and anti-theft devices, may emit electromagnetic interference into the control system if improperly installed. As a result, abnormal signals occur and cause a false diagnosis. Before performing trouble diagnoses, either turn OFF the power to all aftermarket electronic equipment or remove them.

4. Basic knowledge of tools required

Lack of basic knowledge when performing Diagnosis could result in incorrect diagnoses or damage to components. Do not attempt to perform diagnosis without the basic knowledge. A basic understanding of hand tools, such as the trouble diagnosis scan tools, is required to utilize the service manual effectively.

2. Diagnostic trouble codes (DTCs)

1. DTC reading

The DLC is a device for communicating with the TCM. The DTCs stored in the TCM can be read either by connecting a scan tool to the DLC, or by counting the number of flashes of the check trans warning light when pin 12 and pin 4 or pin 5 of the DLC are short-circuited. If the ignition switch is turned ON with the vehicle parked, and pin 12 and pin 4 or pin 5 of the DLC are short-circuited, the check trans warning light flashes and the DTC is displayed. The check trans warning light indicates current and past failure DTCs. Also, the check trans warning light repeats the display 3 times per DTC. If multiple DTCs are stored in the TCM, the DTCs are displayed in ascending order of DTC number. If the DTC is not stored in the TCM, the check trans warning light shows code 12. The flashing DTC display will continue as long as the DLC is short-circuited.

2. DTC type definitions

There are 4 DTC types: Type A, B, C, and E. Among these DTCs, type A and B DTCs are related to emission whereas type C and E DTCs are related to items other than emission.

1) Action taken when DTC sets - Type A

  • The TCM flashes the check trans warning light when the diagnostic runs and fails.
  • The TCM requests the MIL to be illuminated when the diagnostic runs and fails.
  • The TCM records the operating conditions at the time the diagnostic fails. The TCM stores this information in the Failure Records.
  • The ECM records the operating conditions at the time the diagnostic fails. The ECM stores this information in the Freeze Frame/Failure Records.
  • The ECM stores DTC P0700 in ECM history at the time the diagnostic fails.

2) Action taken when DTC sets - Type B

  • The TCM flashes the check trans warning light on the second driving cycle when the diagnostic runs and fails.
  • The TCM requests illumination of the MIL on the second driving cycle when the diagnostic runs and fails.
  • The TCM records the operating conditions at the time the diagnostic fails. The TCM stores this information in the Failure Records.
  • The ECM records the operating conditions at the time the diagnostic fails. The ECM stores this information in the Freeze Frame/Failure Records.
  • The ECM stores DTC P0700 in ECM history during the second driving cycle in which the diagnostic fails.

3) Condition for clearing the MIL, check trans warning light/DTC - Type A or Type B

  • The TCM turns OFF the check trans warning light and cancels the MIL request after the third driving cycle when the diagnostic runs and does not fail.
  • The DTC history is cleared after 40 consecutive warm-up cycles when the diagnostic runs and does not fail.
  • Clear the MIL, check trans warning light, and the DTC with a scan tool.

4) Action taken when DTC sets - Type C

  • The TCM flashes the check trans warning light when the diagnostic runs and fails.
  • The TCM records the operating conditions at the time the diagnostic fails. The TCM stores this information in the Failure Records.

5) Condition for clearing the check trans warning light/DTC - Type C

  • The TCM turns OFF the check trans warning light after the third driving cycle when the diagnostic runs and does not fail.
  • The current DTC clears after the third driving cycle when the diagnostic runs and passes.
  • The DTC history is cleared after 40 consecutive warm-up cycles when the diagnostic runs and does not fail.
  • Clear the check trans warning light and the DTC with a scan tool.

6) Action taken when DTC sets - Type E

  • The TCM does not flash the check trans warning light.
  • The TCM records the operating conditions at the time the diagnostic fails. The TCM stores this information in the Failure Records.

7) Condition for clearing the check trans warning light/DTC - Type E

  • The current DTC clears after the first driving cycle when the diagnostic runs and passes.
  • The DTC history is cleared after 40 consecutive warm-up cycles when the diagnostic runs and does not fail.
  • Clear the DTC with a scan tool.

3. Oral consultation

1. About oral consultation

1) Fully understand the description given by the customer using the transmission control system check sheet.

Reference: When questioning, do not ask random questions. Focus on the system believed to be malfunctioning based on the malfunction symptom and the facts.

2) Determine failure information accurately.

Have concrete understanding based on 5W1H. Example: Low air temperature, during startup, on a steady basis, near the transmission area, metallic sound, etc.

2. Key points of questioning

  • What: Malfunction symptom
  • When: Month and date, time, frequency of occurrence
  • Where: Road conditions
  • In what kinds of conditions: Driving conditions, operation status, weather conditions
  • What happened: What the symptom felt like

3. Transmission control system check sheet

When receiving the vehicle from the customer at the service factory, the failure symptoms and the data on the occurrence of failures must be checked with the customer based on the transmission control check sheet.

Legend

  1. Failure symptoms
  2. Frequency and conditions of failure occurrence

Reasons:

  • Failure symptoms may not be reproducible at the service factory.
  • The customer's complaint may not always turn out to be a malfunction.
  • Notification of incorrect malfunction conditions to the person in charge of repairs may result in unnecessary repair procedures.

The check sheet assists in on-vehicle diagnosis, repair, and repair verification at the service factory.

Copyright Mazda Motor Corporation. All rights reserved.