LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Lexus >> 1993 >> SC 400 >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - System/Component Tests >> Miscellaneous Controls >> Cooling Fan >> Cooling Fan ECM (ES300 & SC400)
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Cooling Fan ECM (ES300 & SC400)

  1. Disconnect negative battery cable. Turn ignition off and wait 20 seconds. Remove cover under instrument panel. Remove lower instrument panel cover and glove box door assembly. Disconnect cooling fan ECM.
  2. Reconnect negative battery cable. Using a DVOM, measure resistance and voltage as indicated in COOLING FAN ECM SPECIFICATIONS table. Make all measurements from harness side of connector. See Fig 1. Repair harness as necessary.
COOLING FAN ECM SPECIFICATIONS

Terminals Condition Value
ES300 
1 & Ground Ignition On Battery Voltage
2 & 3 (1) 77°F (25°C) Approx. 7.8 Ohms
4 & Ground (2) Continuity
5 & Ground Throttle Valve Open No Continuity
5 & Ground Throttle Valve Closed Continuity
8 & Ground A/C Press. Sw. Disc. No Continuity
8 & Ground A/C Press. Sw. Conn. Continuity
9 & 10 (1) 176°F (80°C) Approx. 1.52 Ohms
SC400 
1 & Ground Ignition On Battery Voltage
2 & 3 (1) 68°F (20°C) Approx. 8 Ohms
4 & Ground (2) Continuity
5 & Ground Throttle Open No Continuity
5 & Ground Throttle Closed Continuity
9 & 10 (1) 176°F (80°C) 1.48-1.58 k/Ohms
(1) Coolant temperature.
Fig 1: Identifying Cooling Fan ECM Terminals
G93I79556Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002