Code No. System Diagnosis Trouble Area See page 22 Water Temp. Sensor Signal Open or short circuit in coolant temp. sensor signal. 1. Water temp. sensor circuit 2. Water temp. sensor 3. ECU FI-72 23 Intake Air Temp. Sensor Signal Open or short circuit in intake air temp. sensor. 1. Intake air temp. sensor circuit 2. Intake air temp. sensor 3. ECU FI-38 31 Air Flow Meter Signal Open circuit in Vc signal or Vs and E2 short circuited when idle points are closed. 1. Air flow meter circuit 2. Air flow meter 3. ECU FI-37 32 Air Flow Meter Signal Open circuit in E2 or Vc and Vs short circuited. Same as 31, above. FI-37 41 Throttle Position Sensor Signal Open or short circuit in throttle position sensor signal. 1. Throttle position sensor circuit 2. Throttle position sensor 3. ECU FI-35 42 Vehicle Speed Sensor Signal (A/T): Signal informing ECU that vehicle speed is 2.0 km/h or less has been input ECU for 5 seconds with engine running at 2,500 rpm or more and shift lever is in other than N or P range. (M/T): Signal informing ECU that vehicle speed is 2.0 km/h or less has been input ECU for 5 seconds with engine running at 2,500 rpm or more. 1. Vehicle speed sensor circuit 2. Vehicle speed sensor 3. Torque converter slipping 4. ECU 43 Starter Signal (+ B) No STA signal to ECU when engine is running over 800 rpm. 1. Main relay circuit 2. IG switch circuit (starter) 3. IG switch 4. ECU FI-40 51 Switch Signal Neutral start switch OFF or air condi- tioner switch ON during diagnostic check. 1. Neutral start S/W 2. Air con. S/W 3. ECU 52 Knock Sensor Signal Open or short circuit in knock sensor. 1. Knock sensor circuit 2. Knock sensor 3. ECU 53 Knock Sensor Signal Faulty ECU (KNOCK CPU) ECU