P26A7

P26A7-ENGINE COOLANT BYPASS VALVE POSITION SENSOR CIRCUIT HIGH

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





- When Monitored:
With the ignition key on and battery voltage above 10.4 volts.

- Set Condition:
The Coolant Three Way Valve Position Sensor voltage at Powertrain Control Module (PCM) is above the minimum acceptable threshold.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure.

Diagnostic Test

1. ACTIVE DTC
1. Turn the ignition on.
2. With the scan tool, select View DTCs.

Is the DTC Active at this time?

Yes

- Go To 2

No

- Perform the INTERMITTENT CONDITION diagnostic procedure. Intermittent Condition Test.

2. CHECK THE (K473) COOLANT THREE WAY VALVE POSITION SIGNAL CIRCUIT FOR A SHORT TO VOLTAGE
1. Turn the ignition off.
2. Disconnect the PCM C2 harness connector.
3. Ignition on, engine not running.
4. Measure the voltage on the (K473) Coolant Three Way Valve Position Signal circuit at the PCM C2 harness connector.

Is the voltage above 5.2 volts?

Yes

- Repair the (K473) Coolant Three Way Valve Position Signal circuit for a short to voltage.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

No

- Go To 3

3. CHECK THE (K473) COOLANT THREE WAY VALVE POSITION SIGNAL CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Turn the ignition off.
2. Disconnect the Coolant Three Way Valve harness connector.
3. Measure the resistance of the (K473) Coolant Three Way Valve Position Signal circuit between the Coolant Three Way Valve harness connector and the PCM C2 harness connector.

Is the resistance below 5.0 Ohms?

Yes

- Go To 4

No

- Repair the open in the (K473) Coolant Three Way Valve Position Signal circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

4. CHECK THE (K900) SENSOR GROUND CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Measure the resistance of the (K900) Sensor Ground circuit between the Coolant Three Way Valve harness connector and the PCM C2 harness connector.

Is the resistance below 5.0 Ohms?

Yes

- Go To 5

No

- Repair the (K900) Sensor Ground circuit for an open or high resistance.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

5. CHECK FOR THE (K473) COOLANT THREE WAY VALVE POSITION SIGNAL CIRCUIT SHORTED TO THE (K856) 5-VOLT SUPPLY CIRCUIT
1. Measure the resistance between the (K473) Coolant Three Way Valve Position Signal circuit and the (K856) 5-Volt Supply circuit in the Engine Oil Pressure Sensor harness connector.

Is the resistance above 10k Ohms?

Yes

- Go To 6

No

- Repair the short between the (K856) 5-Volt Supply circuit and the (K473) Coolant Three Way Valve Position Signal circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

6. COOLANT THREE WAY VALVE
1. Reconnect the PCM C2 harness connector.
2. Ignition on, engine not running.
3. With the scan tool, monitor the Engine Oil Pressure Sensor voltage.
4. Connect a jumper between the (K473) Coolant Three Way Valve Position Signal circuit and the (K900) Sensor Ground circuit in the Engine Oil Pressure Sensor harness connector.
5. With the scan tool, view DTCs.

NOTE: The scan tool should display a P26A6-ENGINE COOLANT BYPASS VALVE POSITION SENSOR CIRCUIT LOW DTC as active or pending with the jumper in place.

Does the P26A6-ENGINE COOLANT BYPASS VALVE POSITION SENSOR CIRCUIT LOW DTC set as active or pending with the jumper in place?

Yes

- Verify that there is good pin to terminal contact in the Switch and Powertrain Control Module connectors. Replace the Coolant Three Way Valve if no problems were found in the connector. After the Coolant Three Way Valve is replaced, navigate to Misc Functions, and select the Coolant Three Way Valve Replaced selection to clear the Coolant Three Way Valve actuation counter.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

No

- Go To 7

NOTE: Remove the jumper before continuing.

7. POWERTRAIN CONTROL MODULE (PCM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Coolant Three Way Valve and the Powertrain Control Module (PCM).
2. Look for any chafed, pierced, pinched or partially broken wires.
3. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the Coolant Three Way Valve and Powertrain Control Module connectors.
4. Perform any Technical Service Bulletins that may apply.

Were there any problems found?

Yes

- Repair as necessary.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

No

- Replace and program the Powertrain Control Module. Powertrain Control Module - Removal.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.