Cruze

DTC P2687-P2689

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 00

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

P2688 00

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

P2689 00

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

DTCs P2687, P2688, and P2689 are Type C DTCs.

DTCs P2687, P2688, and P2689 are Type C DTCs.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Fuel System Description

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Ignition ON, the fuel heater relay with turn ON and the fuel heater will turn ON. The Fuel Temperature Sensor parameter on the scan tool will start to rise.

1. Ignition OFF, disconnect the KR22 Fuel Heater Relay.
2. Ignition ON, verify that a test lamp does not illuminate between the fuel heater relay coil control circuit terminal 2 and ground.

⇒	If the test lamp illuminates, test the control circuit for a short to voltage.

3. Verify that a test lamp illuminates between the fuel heater relay coil ignition circuit terminal 1 and ground.

⇒	If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition circuit fuse is open, test or replace the KR22 Fuel Heater Relay.

4. Verify that a test lamp illuminates between the fuel heater relay switch B+ circuit terminal 5 and ground.

⇒	If the test lamp does not illuminate, test the fuel heater relay switch B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal and the F59UA fuse is open, test the control circuit terminal 3 for a short to ground.

5. Ignition OFF, disconnect the harness connector X2 at the K20 Engine Control Module.
6. Test for less than 2 Ω between the control circuit terminal 2 and K20 Engine Control Module terminal 50 X2.

⇒	If greater than the specified range, test the ground circuit for an open/high resistance.

7. Connect the harness connector at the K20 Engine Control Module and disconnect the harness connector at the E11 Fuel Heater.
8. Connect a 15 A fused jumper wire between the fuel heater relay switch B+ circuit terminal 5 and the control circuit terminal 3. Verify a test lamp illuminates between the ignition circuit terminal 2 at the E11 Fuel Heater and ground.

⇒	If the test lamp does not illuminate, test the ignition circuit for an open/high resistance. If the circuit tests normal, test or replace the E11 Fuel Heater.

9. Remove the jumper wire. Verify a test lamp does not illuminate between the ignition circuit terminal 3 at the E11 Fuel Heater and ground.

⇒	If the test lamp illuminates, test the ignition circuit for a short to voltage. If the circuit tests normal, replace the K20 Engine Control Module.

10. Connect a test lamp between the ignition circuit terminal 3 and B+. Verify the test lamp does not illuminate.

⇒	If the test lamp illuminates, test the ignition circuit for a short to ground. If the circuit tests normal, replace the K20 Engine Control Module.

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

Relay Test

1. Ignition OFF, disconnect the KR22 Fuel Heater Relay.
2. Test for 70-110 Ω between terminals 1 and 2.

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

3. Test for infinite resistance between the following terminals:

•

5 and 2

•

5 and 3

•

5 and 1

•

1 and 3

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

4. Test for less than 2 Ω between terminals 3 and 4.

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

5. Install a 20 A fused jumper wire between relay terminal 1 and 12 V. Install a jumper wire between relay terminal 2 and ground. Test for less than 2 Ω between terminals 5 and 3.

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

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.