Diagnostic Procedure

DIAGNOSTIC PROCEDURE DESCRIPTION

STEP	INSPECTION	RESULTS	ACTION
1	Is the customer complaint "Lack of passenger compartment heat" only?	Yes	Inspect the A/C and heater system. Repair or replace the malfunctioning part according to the inspection results.
1		No	Go to the next step.
2	Does the engine speed continue at fast idle?	Yes	Go to the symptom troubleshooting "NO.9 FAST IDLE/RUNS ON". (See NO.9 FAST IDLE/RUNS ON ).
2	Does the engine speed continue at fast idle?	No	Go to the next step.
3	Perform the Cooling Fan Control System Inspection. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION ). Is there any malfunction?	Yes	Repair or replace the malfunctioning part according to the inspection results.
3		No	Go to the next step.
4	Access the ECT1 PID using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 1.5] ). Compare for both the ECT1 PID and the low engine coolant temperature indicator light on instrument cluster condition. Is the low engine coolant temperature indicator light condition according to the ECT1 PID value?	Yes	Go to the next step.
4		No	Inspect the ECT sensor No.1. (See ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION ). If there is any malfunction: Replace the ECT sensor No.1. (See ENGINE COOLANT TEMPERATURE (ECT) SENSOR REMOVAL/INSTALLATION ). If there is no malfunction: Inspect the instrument cluster. (See INSTRUMENT CLUSTER INSPECTION ). Replace the instrument cluster, if necessary. (See INSTRUMENT CLUSTER REMOVAL/INSTALLATION ).
5	Remove the thermostat. (See THERMOSTAT REMOVAL/INSTALLATION ). Inspect the thermostat operation. (See THERMOSTAT INSPECTION ). Is there any malfunction?	Yes	Replace the thermostat. (See THERMOSTAT REMOVAL/INSTALLATION ).
5		No	Go to the next step.
6	Verify the test results. If normal, return to the diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX ). If a malfunction remains, inspect the related Service Bulletins and/or On-line Repair Information and perform repair or diagnosis. If the vehicle is repaired, troubleshooting is completed. If the vehicle is not repaired or additional diagnostic information is not available, reprogram the PCM if a later calibration is available. Retest.