Problem Symptoms Table

WARNING: This page is about a different car, the 2006 Scion tC. However, it is still accessible from the selected car via links, so may be relevant.

Check the circuits for each problem symptom in the order given in the table below and proceed to the relevant troubleshooting page.

HINT:

Inspect the "Fuse" and "Relay" before inspecting the suspected area as shown in the table below.

Inspect each malfunction circuit in numerical order for the corresponding symptom.

If the malfunction still exists even after checking and confirming that all the circuits are normal, replace the A/C amplifier.

SYMPTOM CHART

Symptom	Suspected area	See Procedure
Whole functions of the A/C system do not operate	1. HEATER CONTROL & ACCESSORY ASSEMBLY	HEATER CONTROL & ACCESSORY ASSEMBLY
	2. A/C amplifier assembly	TERMINALS OF ECU
	3. Wire harness or connector	-
Air Flow Control: No blower operation	1. BLOWER W/ FAN MOTOR SUB-ASSEMBLY	BLOWER W/ FAN MOTOR SUB-ASSEMBLY
	2. HEATER CONTROL & ACCESSORY ASSEMBLY	HEATER CONTROL & ACCESSORY ASSEMBLY
	3. A/C amplifier assembly	TERMINALS OF ECU
	4. Wire harness or connector	-
Air Flow Control: No blower control	1. BLOWER W/ FAN MOTOR SUB-ASSEMBLY	BLOWER W/ FAN MOTOR SUB-ASSEMBLY
	2. HEATER CONTROL & ACCESSORY ASSEMBLY	HEATER CONTROL & ACCESSORY ASSEMBLY
	3. A/C amplifier assembly	TERMINALS OF ECU
	4. Wire harness or connector	-
Air Flow Control: Insufficient air comes out	1. BLOWER W/ FAN MOTOR SUB-ASSEMBLY	BLOWER W/ FAN MOTOR SUB-ASSEMBLY
	2. HEATER CONTROL & ACCESSORY ASSEMBLY	HEATER CONTROL & ACCESSORY ASSEMBLY
	3. A/C amplifier assembly	TERMINALS OF ECU
	4. Wire harness or connector	-
Temperature Control: No cool air comes out	1. VOLUME OF REFRIGERANT	VOLUME OF REFRIGERANT
	2. Drive belt tension	DRIVE BELT
	3. REFRIGERANT PRESSURE	REFRIGERANT PRESSURE
	4. Cooler compressor assembly	INSPECTION
	5. PRESSURE SWITCH	PRESSURE SWITCH
	6. AIR MIX CONTROL SERVO MOTOR	AIR MIX CONTROL SERVO MOTOR
	7. HEATER CONTROL & ACCESSORY ASSEMBLY	HEATER CONTROL & ACCESSORY ASSEMBLY
	8. A/C amplifier assembly	TERMINALS OF ECU
	9. Wire harness or connector	-
Temperature Control: No warm air comes out	1. Engine coolant volume	COOLANT
	2. AIR MIX CONTROL SERVO MOTOR	AIR MIX CONTROL SERVO MOTOR
	4. HEATER CONTROL & ACCESSORY ASSEMBLY	HEATER CONTROL & ACCESSORY ASSEMBLY
	5. Heater radiator unit sub-assembly	-
	6. A/C amplifier assembly	TERMINALS OF ECU
	7. Wire harness or connector	-
Temperature Control: Output air is warmer or cooler than the set temperature or response is slow	1. Heater control & accessory assembly	TERMINALS OF ECU
	2. AIR MIX CONTROL SERVO MOTOR	AIR MIX CONTROL SERVO MOTOR
	3. A/C amplifier assembly	TERMINALS OF ECU
Temperature Control: No temperature control	1. HEATER CONTROL & ACCESSORY ASSEMBLY	HEATER CONTROL & ACCESSORY ASSEMBLY
	2. AIR MIX CONTROL SERVO MOTOR	AIR MIX CONTROL SERVO MOTOR
	3. A/C amplifier assembly	TERMINALS OF ECU
No air inlet control	1. AIR INLET SERVO MOTOR	AIR INLET SERVO MOTOR
	2. HEATER CONTROL & ACCESSORY ASSEMBLY	HEATER CONTROL & ACCESSORY ASSEMBLY
	3. A/C amplifier assembly	TERMINALS OF ECU
	4. Wire harness or connector	-
No air outlet control	1. HEATER CONTROL & ACCESSORY ASSEMBLY	HEATER CONTROL & ACCESSORY ASSEMBLY
	2. AIR OUTLET CONTROL SERVO MOTOR	AIR OUTLET CONTROL SERVO MOTOR
	3. A/C amplifier assembly	TERMINALS OF ECU
	4. Wire harness or connector	-
Engine idle up does not occur, or is continuous	1. Cooler compressor assembly	INSPECTION
	2. HEATER CONTROL & ACCESSORY ASSEMBLY	HEATER CONTROL & ACCESSORY ASSEMBLY
	3. A/C amplifier assembly	TERMINALS OF ECU
Brightness does not change when rheostat volume or light control switch is turned	1. Wire harness or connector	-