Cabin Heater Control Circuit Open (Stored)

Test 1 - 3:

Test 4:

Test 5:

SYMPTOM
CABIN HEATER CONTROL CIRCUIT OPEN (STORED)

TEST NOTE
This symptom is diagnosed using the test A. CABIN HEATER PRE-TEST.

WHEN MONITORED
When the DCHA system is off.

SET CONDITION
The DCHA Low Side Driver inside the FCM expects to see a system voltage of 13.8 volts through the DCHA relay coil when the DCHA system is off. This DTC will set if the FCM sees a voltage below 3.5 volts on the Cabin Heater Assist Control circuit during this time.

POSSIBLE CAUSES
- No response from cabin heater module
- DTC(s) present
- Cabin heater inoperable from A/C - heater module (MTC)
- Cabin heater inoperable from auto temp control (ATC)
- Stored DCHA DTC(s) test complete