Cruze

DTC P2687

Ignition voltage is supplied to the coil side of the fuel heater relay whenever the ignition is ON. The engine control module (ECM) provides an ground to control the fuel heater relay. When the ECM is commanding the fuel heater ON, the voltage of the control circuit should be low, near 0 V. When the ECM is commanding the fuel heater OFF, the voltage of the control circuit should be high, near battery voltage.

P2687 01

The ECM detects the fuel heater relay control circuit is shorted to battery for greater than 1 s.

P2687 02

The ECM detects the fuel heater relay control circuit is shorted to ground for greater than 1 s.

P2687 04

The ECM detects the fuel heater relay control circuit is open for greater than 1 s.

P2687 54

The control module detects the fuel heater relay control circuit temperature is too high for greater than 1 s.

DTC P2687 is a Type C DTC.

DTC P2687 is a Type C DTC.

Schematic Reference

Engine Controls Schematics : LLW

Connector End View Reference

Component Connector End Views

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References

1. Ignition ON, command the Fuel Heater Relay ON and OFF with a scan tool. You should hear and feel an audible click.
2. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

1. Ignition OFF, disconnect the KR22 Fuel Heater Relay from the under bonnet auxiliary fuse block.
2. Connect a test lamp between the control circuit terminal 86 and B+.
3. Ignition ON, command the Fuel Heater Relay ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.

⇒	If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the K20 Engine Control Module.

⇒	If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K20 Engine Control Module.

4. Ignition OFF, connect a test lamp between the control circuit terminal 2 and the ignition 1 voltage circuit terminal 1.
5. Ignition ON, command the fuel heater relay ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.

⇒	If the test lamp is always OFF, repair the ignition 1 voltage circuit for an open/high resistance.

6. If all circuits test normal, test or replace the KR22 Fuel Heater Relay.

Dynamic Test

1. Ignition OFF, disconnect the KR22 Fuel Heater Relay from the under bonnet auxiliary fuse block.
2. Test for 70-110 Ω between terminals 1 and 2.

⇒	If not within the specified range, replace the KR22 Fuel Heater Relay.

3. Test for infinite resistance between the following terminals:

•

30 and 86

•

30 and 87

•

30 and 85

•

85 and 87

⇒	If not the specified value, replace the KR22 Fuel Heater Relay.

4. Install a 20 A fused jumper wire between relay terminal 85 and B+. Install a jumper wire between relay terminal 86 and ground. Test for less than 2 Ω between terminals 30 and 87.

⇒	If greater than the specified range, replace the KR22 Fuel Heater Relay.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References