HVAC System - Manual

DTC B1004

DTC DESCRIPTORS

DTC B0484 00
Auxiliary Heater System Locked

DTC B0485 00
Auxiliary Heater Start Counter Overrun

DTC B0486 00
Auxiliary Heater Cold Blow Time Exceeded

DTC B0488 00
Auxiliary Heater Overheat Counter Overrun

DTC B048A 00
Auxiliary Heater Start Time Exceeded

DTC B1000 00
Electronic Control Unit

DTC B1004 00
Keep Alive Memory Reset

DTC B1424 00
Device Voltage Low

DTC B1425 00
Device Voltage High

DTC B1439 00
Intermittent Device Voltage Range/Performance

DIAGNOSTIC FAULT INFORMATION






IMPORTANT: Always perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview

CIRCUIT/SYSTEM DESCRIPTION
The coolant heater has an electronic control unit that monitors voltage level, temperature, time, and the amount of times the coolant heater has started and turned OFF. If an out of range condition is recognized by the coolant heater electronic control module, a code will be set.

CONDITIONS FOR RUNNING THE DTC
Engine running

CONDITIONS FOR SETTING THE DTC
Fuel operated heater has recognized an out of range condition in the controller.

ACTION TAKEN WHEN THE DTC SETS
Fuel operated heater is disabled.

CONDITIONS FOR CLEARING THE DTC
DTC must be cleared with a scan tool.

CIRCUIT/SYSTEM VERIFICATION
Start the vehicle. Command the coolant heater ON and OFF with a scan tool. The coolant heater should turn ON and OFF with each command.

COMPONENT TESTING
1. Ignition OFF, disconnect the 10-pin pigtail connector at the coolant heater.
2. Verify that a test lamp illuminates between the voltage supply circuit on the body side of the 10-pin connector and ground.
- If the test lamp does not illuminate, repair the voltage supply circuit for a short to ground or an open/high resistance. If the voltage supply circuit tests normal, replace the controller.
3. Verify that a test lamp illuminates between the ground circuit on the body side of the 10-pin connector and battery voltage.
- If the test lamp does not illuminate, repair the ground circuit for a short to voltage or an open/high resistance. If the ground circuit tests normal, replace the controller.
4. Check the coolant level and flow through the coolant heater.
- If the coolant level or flow is not correct, refer to LINK.
5. Check the combustion air inlet pipe for blockage.
- If the combustion air inlet is blocked, repair or replace the inlet tube. If the combustion air inlet tube is not blocked, replace the controller.
6. Verify that the fuel supply to the coolant heater is correct.
- If the fuel supply is not correct, refer to LINK.
7. If the coolant heater tests normal, replace the coolant heater.

REPAIR INSTRUCTIONS

IMPORTANT: Always perform the Diagnostic Repair Verification after completing the diagnostic procedure.

CELL LINK replace the coolant heater