Using Scan Tool
- Connect scan tool to Data Link Connector (DLC). DLC is located on left side of steering column, just above hood release handle. Turn ignition switch to ON position. If scan tool display is energized (not blank), go to next step. If scan tool display is not energized (blank), or if scan tool displays any NO RESPONSE message, diagnose module communications network. See appropriate BODY CONTROL MODULES article in ACCESSORIES & EQUIPMENT.
- Using scan tool, select READ DTCS on display screen. Record all DTCs and available freeze frame data displayed. If any of the following PCM related DTCs are displayed, see appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE. If the following DTCs codes are not displayed, go to next step.
- DTC P0116: ECT SENSOR VOLTAGE TOO LOW
- DTC P0117: ECT SENSOR VOLTAGE TOO HIGH
- DTC P0645: A/C CLUTCH RELAY CIRCUIT
- DTC P1488: 5 VOLT SUPPLY OUTPUT TOO LOW
- DTC P1496: 5 VOLT SUPPLY OUTPUT TOO LOW
- DTC P1598: A/C PRESSURE SENSOR VOLTS TOO HIGH
- DTC P1599: A/C PRESSURE SENSOR VOLTS TOO LOW
- Using scan tool, select READ DTCS. If scan tool displays HVAC system DTCs or fault messages, record all messages displayed and perform appropriate test(s). See HVAC DIAGNOSTIC TEST DIRECTORY table. If no HVAC system DTCs or fault messages are present, go to next step.
- Review customer complaint and check for any intermittent faults related to complaint. DTCs or fault messages may occur separately or in various combinations. When diagnosing a system with many apparent problems, a sequence of tests may be required. Repair DTC/fault messages in order in which they were displayed. After repairs have been completed, ensure problems or faults have been corrected by clearing codes and checking operation of repaired system or circuit. See CLEARING DIAGNOSTIC TROUBLE CODES . When requested, perform verification test. See BODY VERIFICATION TEST VER-1 under VERIFICATION TESTS.
HVAC DIAGNOSTIC TEST DIRECTORY
| DTC/Fault Message Description |
Go To Test |
| A/C HEAD, A/C SWITCH FAILURE |
A |
| A/C HEAD, EBL INPUT SHORTED TO BATTERY |
B |
| A/C HEAD, EBL INPUT SHORTED TO GROUND |
C |
| A/C HEAD, EBL SWITCH STUCK |
D |
| BLEND DOOR FEEDBACK FAILURE |
E |
| BLEND DOOR INPUT OPEN/SHORTED TO GROUND |
F |
| BLEND DOOR INPUT SHORTED TO BATTERY |
G |
| BLEND DOOR OUTPUT SHORTED TO BATTERY |
H |
| BLEND DOOR OUTPUT SHORTED TO GROUND |
I |
| BLEND DOOR STALL TEST FAILURE |
J |
| BLOWER MOTOR INOPERATIVE |
K |
| BLOWER MOTOR SPEEDS INCORRECT |
L |
| COMMON OUTPUT SHORTED TO BATTERY |
M |
| COMMON OUTPUT SHORTED TO GROUND |
N |
| MODE DOOR FEEDBACK FAILURE |
O |
| MODE DOOR FEEDBACK FAILURE |
P |
| MODE DOOR INPUT OPEN/SHORTED TO GROUND |
Q |
| MODE DOOR INPUT SHORTED TO BATTERY |
R |
| MODE DOOR OUTPUT SHORTED TO BATTERY |
S |
| MODE DOOR OUTPUT SHORTED TO GROUND |
T |
| ODE DOOR STALL TEST FAILURE |
U |
| RECIRC DOOR OUTPUT SHORTED TO BATTERY |
V |
| RECIRC DOOR OUTPUT SHORTED TO GROUND |
W |
| RECIRC DOOR STALL TEST FAILURE |
X |