LEMON Manuals: Even more car manuals for everyone
Home >> Lexus >> 2024 >> TX 350 Base, FWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 51 (Rear Motor Generator Control System - Diagnostic Codes) >> REAR MOTOR GENERATOR CONTROL SYSTEM (for PHEV Model) >> DTC P26F4-31: Coolant Pump "C" Control Circuit No Signal [12/2023 - ] >> Description

DTC P26F4-31: Coolant Pump "C" Control Circuit No Signal [12/2023 - ]: Description

WARNING: This page is about a different car, the 2024 Lexus TX 550h+. However, it is still accessible from the selected car via links, so may be relevant.

The rear motor generator control ECU (MGR ECU) detects the rear motor (MGR) temperature based on signals from the rear motor temperature sensors and activates the OIL PMP RR relay and oil pump driver (oil pump assembly).

The rear motor generator control ECU (MGR ECU) monitors RNOP signals from the oil pump driver and detects malfunctions.

DTC No. Detection Item DTC Detection Condition Trouble Area MIL Warning Indicate DTC Output from Priority Note
P26F4-31 Coolant Pump "C" Control Circuit No Signal When the OIL PMP RR relay is on, the RNOP pulse signal is not output.
(2 trip detection logic)
  • Rear transaxle with motor assembly
  • OIL PMP RR fuse
  • OIL PMP RR relay
  • EV motor control inverter assembly
  • Wire harness or connector
Does not come on Master Warning:
Comes on
Rear Motor Generator A SAE Code: P26F4

HINT: 

The oil pump assembly cannot be activated only with the OIL PMP RR relay on. It is activated after receiving the command signals (ROPM) from the rear motor generator control ECU (MGR ECU).