B10B3

B10B3-14-CABIN HEATER 1 CONTROL - CIRCUIT SHORT TO GROUND OR OPEN

For a complete wiring diagram, refer to the Wiring Information.

Theory of Operation

Three relays are used for the electric Positive Temperature Coefficient (PTC) heater system. The PTC relays are used to switch fused battery voltage directly to the heating elements of the PTC heater unit when requested by the Powertrain Control Module (PCM). The PTC relays are activated through a ground path provided by the Body Control Module (BCM).

- When Monitored:
With the ignition on.

Output on (short to ground check).

Output off (open check).

- Set Condition:
If the Body Control Module (BCM) detects the (K360) PTC 1 Relay Control circuit is open or shorted to ground.





1. VERIFY THE DTC IS ACTIVE

WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts, or fan. Do not wear loose clothing. Failure to follow these instructions can result possible serious or fatal injury.

NOTE: Before erasing stored DTCs, record these conditions. Attempting to duplicate these conditions may assist when checking for an active DTC.

1. Turn the ignition on.
2. With the scan tool, erase DTCs.
3. Turn the ignition off and wait 30 seconds.
4. Turn the ignition on and wait 30 seconds.
5. With the scan tool, read DTCs.

Does the scan tool display this DTC as active?

Yes

- Go To 2

No

- Test complete, the condition or conditions that originally set this DTC are not present at this time. Using the wiring diagrams as a guide, check all related splices and connectors for signs of water intrusion, corrosion, pushed out or bent terminals, and correct pin tension.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

2. CHECK THE CABIN HEATER 1 RELAY
1. Turn the ignition off.
2. Remove the Cabin Heater 1 Relay and substitute it with a known good relay.
3. Turn the ignition on.
4. With the scan tool, erase DTCs.
5. Turn the ignition off and wait 30 seconds.
6. Turn the ignition on and wait 30 seconds.
7. With the scan tool, read DTCs.

Is the status Active for this DTC?

Yes

- Go To 3

No

- Replace the Cabin Heater 1 Relay. Cabin Heater Relay - Removal.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

3. CHECK THE (K360) PTC 1 RELAY CONTROL CIRCUIT FOR A SHORT TO GROUND




1. Turn the ignition off.
2. Remove the Cabin Heater 1 Relay.
3. Disconnect the BCM D harness connector.
4. Measure the resistance between ground and the (K360) PTC 1 Relay Control circuit.

Is the resistance above 10k Ohms?

Yes

- Go To 4

No

- Repair the short to ground in the (K360) PTC 1 Relay Control circuit.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

4. CHECK THE (K360) PTC 1 RELAY CONTROL CIRCUIT FOR AN OPEN




1. Measure the resistance of the (K360) PTC 1 Relay Control circuit between the Cabin Heater 1 Relay harness connector and the BCM D harness connector.

Is the resistance below 5.0 Ohms?

Yes

- Go To 5

No

- Repair the open in the (K360) PTC 1 Relay Control circuit.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

5. INSPECT RELATED WIRING AND CHECK FOR TSBS
1. Turn the ignition off.
2. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Cabin Heater 1 Relay and the BCM.
3. Look for any chafed, pierced, pinched, or partially broken wires.
4. Look for broken, bent, pushed out or corroded terminals.
5. Perform any Technical Service Bulletins that may apply.

Were any problems found?

Yes

- Repair as necessary.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Replace the BCM. Body Control Module - Removal.
- Perform the BODY VERIFICATION TEST. Body Verification Test.