Auxiliary Heater Diagnostic Starting Point 1998
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
DEFINITION: This test will verify the operation of the auxiliary fuel-fired heater, and correct any problems found. | ||||
1 | Did you perform the HVAC System Check? | -- | Go to Step 2 | Go to HVAC System Check |
2 | Does the auxiliary heater run continuously? | -- | Go to Step 3 | |
3 | Using a scan tool, display the Ambient Air Temperature Sensor (AAT) value. Is the ambient air temperature less than the specified value? | 2°C (35.6°F) | Go to Step 5 | Go to Step 4 |
4 |
Does the scan tool display the specified value? | High | Go to Step 5 | Go to Step 9 |
5 |
Does the Auxiliary Fuel-Fired Heater ignite? | -- | Go to Step 12 | Go to Step 6 |
6 |
Does the scan tool indicate the specified values? | High/Low | Go to Step 7 | Go to Heat Switch Inoperative |
7 | Using a scan tool, activate the Auxiliary Fuel-Fired Heater. Does the Auxiliary Fuel-Fired Heater ignite? | -- | Go to Step 8 | |
8 | Replace HTCM. Did you complete the repair? | -- | System OK | -- |
9 | Connect a DVOM between CKT 39 (PNK) wire, cavity B, at the Auxiliary Heater Service Port and ground. Is the voltage equal to the specified value? | Battery Voltage - 0.5 volts | Go to Step 10 | Go to Step 11 |
10 |
Did you complete the repair? | -- | Go to Step 5 | -- |
11 | Locate and repair no voltage condition on CKT 39 (PNK) wire. Did you complete the repair? | -- | Go to Step 5 | -- |
12 | Allow the Auxiliary Fuel-Fired Heater to run for 5 minutes. Does hot air come out of the panel vents? | -- | System OK | Go to Heating Insufficient |
