B269A
DTC B269A, B269C, or B269D
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.
DTC Descriptor
DTC B269A
- Heater Coolant Pump Control Circuit Open
DTC B269C
- Heater Coolant Pump Control Circuit Low
DTC B269D
- Heater Coolant Pump Control Circuit High
Diagnostic Fault Information
Circuit/System Description
The primary purpose of the heater core coolant pump is to circulate engine coolant through the HVAC heater core when heat is required in the cabin for comfort. This normally happens when the vehicle is in an Auto Stop and the mechanical pump is not spinning. If the HVAC control module has determined heat is needed for the cabin, a request is sent via serial data to the engine control module to turn the pump ON. The engine control module controls the auxiliary coolant pump relay via the heater core coolant pump relay control circuit. The heater core coolant pump relay supplies voltage to the heater core coolant pump.
Conditions for Running the DTC
* The 12 V battery voltage is greater than or equal to 9 V.
* The auxiliary heater coolant pump enable is commanded.
Conditions for Setting the DTC
The powertrain control module detects the Auxiliary Heater Coolant Pump Relay Enable circuit is open, shorted to voltage or shorted to ground.
Action Taken When the DTC Sets
DTCs B269A, B269C, and B269D are type B DTCs.
Conditions for Clearing the DTC
DTCs B269A, B269C, and B269D are type B DTCs.
Reference Information
Schematic Reference
HVAC Schematics Electrical Diagrams
Connector End View Reference
Component Connector End Views Fuel Pump and Level Sensor Assembly
Description and Operation
Automatic HVAC Description and Operation Description and Operation
Electrical Information Reference
* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs
Scan Tool Reference
Control Module References Control Module References for scan tool information
Circuit/System Testing
1. Ignition OFF, disconnect the KR33 auxiliary heater coolant pump relay, ignition ON.
2. Verify a test lamp illuminates between the B+ circuit terminal 30 and ground.
• If the test lamp does not illuminate and the circuit fuse is good
1. Ignition OFF.
2. Test for less than 2 ohms in the B+ circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, verify the fuse is not open and there is voltage at the fuse.
• If the test lamp does not illuminate and the circuit fuse is open
1. Ignition OFF.
2. Test for infinite resistance between the B+ circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance,
3. Test for greater than 5 ohms between the control circuit terminal 85 and ground.
• If less than 5 ohms, repair the short to ground on the circuit.
• If greater than 5 ohms, test or replace the KR33 auxiliary heater coolant pump relay.
• If the test lamp illuminates
3. Verify a test lamp illuminates between the B+ circuit terminal 86 and ground.
• If the test lamp does not illuminate
1. Ignition OFF.
2. Test for less than 2 ohms in the B+ circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If the test lamp illuminates
4. Connect a test lamp between the B+ circuit terminal 86 and the control circuit terminal 85.
5. Disconnect the harness connector at the K20 Engine Control Module.
6. Connect a 3 A fused jumper wire between terminal 47 and ground.
7. Verify the test lamp turns ON and OFF when moving the jumper to and from the provided ground.
• If the test lamp is always OFF
1. Ignition ON.
2. Test for less than 1 V between the control circuit and ground.
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V, repair the open/high resistance in the circuit.
• If the test lamp is always ON
Repair the short to ground on the circuit.
• If the test lamp turns ON and OFF
8. Verify a test lamp does not illuminate between the control circuit terminal 87 and ground.
• If the test lamp illuminates
Repair the short to voltage on the circuit.
• If the test lamp does not illuminate
9. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the G17 heater coolant pump.
10. Test for less than 10 ohms between the G17 heater coolant pump ground circuit terminal 1 and ground.
• If 10 ohms or greater
1. Ignition OFF.
2. Test for less than 2 ohms in the ground circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, repair the open/high resistance in the ground connection.
• If less than 10 ohms
11. Connect the harness connector at the G17 heater coolant pump.
12. Ignition ON, connect a 15 A fused jumper wire between the B+ circuit terminal 30 and the control circuit terminal 87.
13. Verify the G17 heater coolant pump is activated.
• If the G17 heater coolant pump does not activate
1. Ignition OFF.
2. Test for less than 2 ohms in the control circuit terminal 87 end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, test or replace the G17 heater coolant pump.
• If the G17 heater coolant pump activates
14. Test or replace the KR33 auxiliary heater coolant pump relay.
15. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
16. Verify the DTC does not set.
• If the DTC sets
Replace the K20 engine control module.
• If the DTC does not set
17. All OK
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.