LEMON Manuals: Even more car manuals for everyone
Home >> Mazda >> 2024 >> CX-90 Turbo Select >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 17 (On-Board Diagnostic - Pcm (VIN A) (3 Of 4)) >> DTC P143B-00: Backup Power System: Low Input Of Sub Battery Power

DTC P143B-00: Backup Power System: Low Input Of Sub Battery Power

WARNING: This page is about a different variant/trim than selected.
P143B: 00 (PCM (PYUL)) DETECTION CONDITION AND POSSIBLE CAUSE

System malfunction location Backup power system: Low input of sub battery power
Detection condition
  • The following conditions continue for 5 consecutive drive cycles.
    • The backup power unit measures the voltage when the secondary battery energizes the discharge circuit inside the backup power unit when the engine switch is turned ON (the engine is stopped or rotating).
    • The PCM receives the above measurement results from the backup power supply unit and updates the voltage.
    • The updated voltage is lower than the standard.
Fail-safe
  • Inhibits the auto door lock operation. (With auto door lock system)
  • Displays/turns on shift system warning indication/warning light.
  • Inhibits engine-stop by i-stop control.
Possible cause
  1. Sub battery malfunction (Refer to [SUB BATTERY INSPECTION ] in service information).
  2. Malfunction in wiring harness (including connector/terminal) between sub battery and backup power supply unit (See CIRCUIT INSPECTION .) (See CONNECTOR INSPECTION .)
  3. PCM connector or terminal malfunction (See CONNECTOR INSPECTION .)
  4. Backup power supply unit malfunction (backup power supply unit internal current sensor malfunction or backup power supply unit internal voltage sensor malfunction) (Refer to [BACKUP POWER SUPPLY UNIT REMOVAL/INSTALLATION ] in service information).
  5. PCM malfunction (Refer to [PCM REMOVAL/INSTALLATION ] in service information).
Repeatability verification procedure
  1. Clear the DTC recorded in the memory. (See CLEARING DTC .)
  2. Replicate the vehicle conditions at the time the DTC was detected using the following procedure.
    WARNING:
    • Observe legal speed limits when driving the vehicle and perform the procedure in a location where safety can be assured.
    • To prevent an accident, work with two people when the vehicle is being driven (one person drives vehicle, other person operates M-MDS).
    • Try to reproduce the malfunction by driving the vehicle based on the values in the freeze frame data/snapshot data.
G16689130Courtesy of MAZDA MOTORS CORP.
1 Sub battery
2 Backup power supply unit
3 PCM
scientia non olet · About LEMON Manuals