Both fans do not run at high speed with the A/C on (but both fans run at low speed and the A/C compressor operates with the A/C on)
Diagnostic procedure
  1. A/C pressure sensor troubleshooting: A/C pressure sensor circuit low voltage, L13Z1 engine, R18A2 engine, K20Z4 engine, A/C pressure sensor circuit high voltage, L13Z1 engine, R18A2 engine, K20Z4 engine
  2. ECT troubleshooting: ECT sensor 2 circuit low voltage, L13Z1 engine, R18A2 engine, K20Z4 engine, ECT sensor 2 circuit high voltage, L13Z1 engine, R18A2 engine, K20Z4 engine
Also check for
  • Powertrain DTCs
  • Cleanliness and tightness of all terminals