Aux Heater Coolant Pump Circuit Short to Ground
The B2468 code indicates that the vehicle's control module has detected a short to ground in the auxiliary heater coolant pump circuit. This pump circulates engine coolant through the heater core when the engine is cold or idling, allowing the cabin heating system to work efficiently before the engine reaches normal operating temperature. A short to ground means there is an unwanted electrical connection between the pump's power wire and the vehicle chassis, preventing the pump from operating correctly and potentially triggering circuit protection.
1. Commonly Affected Makes
2. Most Common Causes
- Short to ground in the auxiliary heater coolant pump circuit wiring
- Internally shorted auxiliary heater coolant pump
- Damaged, corroded, or moisture-contaminated wiring connector or harness
- Blown fuse in the related circuit
- Faulty HVAC control module or engine control module
- Loose terminal or bent pins in the pump connector
3. Symptoms You Will Notice
- Insufficient cabin heat, especially at idle or cold start
- Illuminated check engine light or service heater light
4. Step-by-Step Diagnosis
Check for blown fuses in the auxiliary heater coolant pump circuit
Inspect the pump connector and wiring for damage, corrosion, or moisture
Test the pump for internal short using a multimeter (resistance to ground)
Verify continuity and insulation of the pump power and ground circuits
If wiring and pump are okay, test the control module output signals
5. Frequently Asked Questions
Is it safe to drive?▼
Yes, but you may have reduced cabin heating. The vehicle remains drivable, but the issue should be addressed to avoid potential electrical problems.
How much does it cost to fix?▼
Typically $150 to $400, depending on whether the pump or wiring needs replacement and labor rates.