Symptom Chart

SYMPTOM CHART

Condition	Possible Sources	Action
The steering wheel control switch is inoperative/does not operate correctly	Circuitry short/open Steering wheel control switch EATC module	Go to Pinpoint Test E .
No communication with the electronic automatic temperature control (EATC) module	Fuse(s) Circuitry short/open EATC module communication network	REFER to MODULE COMMUNICATIONS NETWORK .
The EATC system is inoperative, intermittent or incorrect operation	Fuse(s) Circuitry short/open Input sensor(s)/erratic input signals Automatic temperature control aspirator hose and elbow	Go to Pinpoint Test G .
Incorrect/erratic direction of airflow from outlets - manual climate control	Function selector switch Vacuum hose A/C vacuum reservoir tank and check valve Vacuum control motor Vacuum actuator arm Mode door	Go to Pinpoint Test H .
Incorrect/erratic direction of airflow from outlets - EATC	EATC module ATC solenoid and manifold assembly Vacuum hose A/C vacuum reservoir tank and check valve Vacuum control motor Vacuum actuator arm Mode door	Go to Pinpoint Test I .
Insufficient, erratic or no heat	Low engine coolant level Engine overheating Plugged or partially plugged heater core Temperature blend door is binding or stuck A/C electric blend door actuator Incorrect heater control valve operation Heater hose is kinked or binding	Go to Pinpoint Test J .
The air conditioning (A/C) is inoperative/does not operate correctly	Fuse(s) Circuitry short/open A/C system discharged/low charge A/C pressure cutoff switch A/C control Function selector switch A/C cycling switch A/C compressor clutch air gap A/C clutch relay	Go to Pinpoint Test K .
The air conditioning (A/C) is always on	Circuitry short A/C control A/C compressor clutch air gap A/C clutch relay	Go to Pinpoint Test L .
The temperature control is inoperative/does not operate correctly - manual climate control	Fuse Temperature blend door actuator control Temperature blend door A/C electronic blend door actuator motor Circuitry open/shorted	Go to Pinpoint Test M .
The blower motor is inoperative - manual climate control	Fuse Circuitry open/shorted A/C blower motor switch Blower motor relay A/C blower motor	Go to Pinpoint Test N .
The blower motor does not operate correctly - manual climate control	Circuitry short A/C blower motor resistor A/C blower motor switch Blower motor high speed relay	Go to Pinpoint Test O .
The blower motor is inoperative - EATC	Fuse Circuitry short/open Blower motor relay A/C blower motor A/C blower motor speed control	Go to Pinpoint Test P .
The blower motor does not operate correctly - EATC	Circuitry short/open A/C blower motor speed control EATC module	Go to Pinpoint Test Q .
The auxiliary blower motor is inoperative	Fuse Circuitry short/open Auxiliary blower motor relay Auxiliary blower motor	Go to Pinpoint Test R .
The auxiliary blower motor does not operate correctly using the front auxiliary blower motor switch	Circuitry short/open Auxiliary blower motor switch Auxiliary blower motor resistor	Go to Pinpoint Test S .
The panel/floor control is inoperative using the front auxiliary climate controls	Circuitry short/open Front auxiliary control panel Auxiliary mode door actuator Mode door	Go to Pinpoint Test T .
The temperature control is inoperative using the front auxiliary climate controls	Fuse Circuitry short/open Front auxiliary control panel Auxiliary blend door actuator Temperature blend door	Go to Pinpoint Test U .
The panel/floor and cool/warm controls are inoperative using the front auxiliary climate controls	Fuse Circuitry short/open Auxiliary blower motor switch Front auxiliary control panel	Go to Pinpoint Test V .
Insufficient air conditioning (A/C) cooling	Low refrigerant level A/C cycling switch Temperature blend door actuator control A/C pressure cutoff switch Heater control valve Vacuum line blocked or leaking	Go to Pinpoint Test W .
The dual temperature control is inoperative/does not operate correctly - Dual Zone EATC	Temperature blend door/actuator broken/binding EATC module	CHECK the temperature blend doors/actuators for a binding or broken condition. If no condition is found, INSTALL a new EATC module. REFER to CLIMATE CONTROL . TEST the system for normal operation.
The temperature set point does not repeat after turning the ignition switch OFF	Open fuse Circuitry short/open EATC module	VERIFY the battery junction box (BJB) fuse 28 (10A) is OK. If OK, CHECK circuit SBP28 (GN/RD) for a short or open and repair as necessary. If OK, INSTALL a new EATC module. REFER to CLIMATE CONTROL .
The temperature display will not switch between Celsius and Fahrenheit	EATC module	INSTALL a new EATC module. REFER to CLIMATE CONTROL .
Inaccurate external temperature display	DATC module	REFER to description and operation of the DATC External Temperature Display. If the external temperature display is not operating as described and no DTC is present, CARRY OUT the Temperature Sensor - Ambient . If the sensor tests OK, INSTALL a new DATC module. REFER to CLIMATE CONTROL . TEST the system for normal operation.