GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The ignition 1 relay is a normally open relay. The relay armature is held in the open position by spring tension. Battery positive voltage is supplied directly to the relay coil and the armature contact at all times. The engine control module (ECM) supplies the ground path to the relay coil control circuit via an internal integrated circuit, called an output driver module. When the ECM commands the relay ON, ignition 1 voltage is supplied to the ECM through the ETC fuse in the underhood fuse block. This ignition 1 voltage input to the ECM provides the ignition power for the electronic throttle control (ETC) circuitry and is also used to confirm the relay contacts have closed. A voltage less than 10 volts indicates an open, high resistance, or a short to ground in the ignition 1 voltage circuit to the ECM. This DTC will set when the ECM detects less than 10 volts on the ignition 1 voltage circuit to the ECM, after the ignition switch is turned ON.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0689 Engine Controls Ignition Relay Feedback Circuit Low Voltage

Conditions for Running the DTC

The battery voltage is more than 11 volts for 1.5 seconds with the ignition ON.

Conditions for Setting the DTC

The ECM detects less than 10 volts on the ignition 1 voltage circuit for more than 200 milliseconds.

Action Taken When the DTC Sets

    • The control module stores the DTC information into memory when the diagnostic runs and fails.
    • The malfunction indicator lamp (MIL) will not illuminate.
    • The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Failure Records.
    • The driver information center, if equipped, may display a message.

Conditions for Clearing the DTC

    • A current DTC Last Test Failed clears when the diagnostic runs and passes.
    • A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other non-emission related diagnostic.
    • Clear the DTC with a scan tool.

Diagnostic Aids

    • The ignition 1 relay will remain powered up for 15 seconds after the ignition switch is turned OFF.
    • This diagnostic table assumes that the vehicle battery is fully charged. Refer to Battery Inspection/Test in Engine Electrical.
    • The following underhood fuse block terminal locations correspond to the ignition 1 relay circuits:
       - F13--Ignition 1 voltage circuit.
       - F14--Ignition 1 relay coil control circuit.
       - H13--Battery positive voltage circuit to the ignition 1 relay coil.
       - H14--Battery positive voltage circuit to the ignition 1 relay armature.

Step

Action

Values

Yes

No

Schematic Reference: Engine Controls Schematics

Connector End View Reference: Engine Control Module Connector End Views or Engine Controls Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

--

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2

If DTCs P0686 or DTC P0687 are set along with DTC P0689, then DTC P0686 or DTC P0687 must be diagnosed first.

Is DTC P0686 or DTC P0687 also set?

--

Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information

Go to Step 3

3

  1. Observe the Freeze Frame/Failure Records for this DTC.
  2. Turn OFF the ignition for 30 seconds.
  3. Turn ON the ignition, with the engine OFF.
  4. 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.

Did the DTC fail this ignition?

--

Go to Step 4

Go to Intermittent Conditions

4

  1. Turn ON the ignition, with the engine OFF.
  2. Probe both test points of the ETC fuse in the underhood fuse block with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp in Wiring Systems.

Does the test lamp illuminate on both test points of the ETC fuse?

--

Go to Step 8

Go to Step 5

5

Does the test lamp illuminate on one test point of the ETC fuse?

--

Go to Step 6

Go to Step 10

6

  1. Turn OFF the ignition.
  2. Disconnect the negative battery cable at the battery. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.
  3. Disconnect the underhood fuse block electrical connector that contains the ignition 1 voltage circuit from the ETC fuse to the engine control module (ECM). Refer to Underhood Electrical Center or Junction Block Replacement in Wiring Systems.
  4. Disconnect the ECM electrical connector that contains the ignition 1 voltage circuit from the ETC fuse. Refer to Engine Control Module Replacement .
  5. Probe the ignition 1 voltage circuit at the ECM electrical connector with a test lamp that is connected to battery positive voltage. Refer to Probing Electrical Connectors in Wiring Systems.

Does the test lamp illuminate?

--

Go to Step 20

Go to Step 7

7

Test the underhood fuse block bus bar circuit from the ETC fuse to the underhood fuse block electrical connector for a short to ground. Refer to Circuit Testing in Wiring Systems.

Did you find a condition?

--

Go to Step 22

Go to Step 19

8

  1. Turn OFF the ignition.
  2. Disconnect the negative battery cable at the battery. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.
  3. Disconnect the underhood fuse block electrical connector that contains the ignition 1 voltage circuit from the ETC fuse to the ECM. Refer to Underhood Electrical Center or Junction Block Replacement in Wiring Systems.
  4. Disconnect the ECM electrical connector that contains the ignition 1 voltage circuit from the ETC fuse. Refer to Engine Control Module Replacement .
  5. Measure the resistance of the ignition 1 voltage circuit from the underhood fuse block electrical connector to the ECM electrical connector with a DMM. Refer to Troubleshooting with a Digital Multimeter in Wiring Systems.

Does the resistance measure the greater than the specified value?

3 ohms

Go to Step 21

Go to Step 9

9

Test the underhood fuse block ignition 1 voltage bus bar circuit from the ETC fuse to the underhood fuse block electrical connector for a high resistance or an open. Refer to Circuit Testing in Wiring Systems.

Did you find a condition?

--

Go to Step 22

Go to Step 19

10

  1. Turn OFF the ignition.
  2. Remove the ignition 1 relay from the underhood fuse block with the J 43244 Relay Puller Pliers. Refer to Relay Replacement in Wiring Systems.
  3. Notice: Refer to Test Probe Notice in the Preface section.

  4. Probe the battery positive voltage terminal for the ignition 1 relay armature at the underhood fuse block with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

--

Go to Step 11

Go to Step 12

11

Test the underhood fuse block ignition 1 voltage bus bar circuit between the ignition 1 relay and the ETC fuse for a high resistance or an open. Refer to Circuit Testing in Wiring Systems.

Did you find a condition?

--

Go to Step 22

Go to Step 13

12

Probe the mounting stud for the battery positive cable at the underhood fuse block with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

--

Go to Step 22

Go to Symptoms - Engine Electrical in Engine Electrical

13

Measure the resistance from terminal #85 of the ignition 1 relay to terminal #86 with a DMM. Refer to Troubleshooting with a Digital Multimeter in Wiring Systems.

Does the resistance measure within the specified range?

70-110 ohms

Go to Step 14

Go to Step 23

14

Measure the resistance from terminal #30 of the ignition 1 relay to terminal #87 with a DMM.

Does the DMM display the specified value?

∞ ohms

Go to Step 15

Go to Step 23

15

Measure the resistance from terminal #30 of the ignition 1 relay to terminal #85 with a DMM.

Does the DMM display the specified value?

∞ ohms

Go to Step 16

Go to Step 23

16

Measure the resistance from terminal #85 of the ignition 1 relay to terminal #87 with a DMM.

Does the DMM display the specified value?

∞ ohms

Go to Step 17

Go to Step 23

17

  1. Connect a 20-amp fused jumper wire from the battery positive cable at the battery to the ignition 1 relay terminal #85. Refer to Using Fused Jumper Wires in Wiring Systems.
  2. Connect a jumper wire from the negative battery cable at the battery to the ignition 1 relay terminal #86.
  3. Measure the resistance from terminal #30 of the ignition 1 relay to terminal #87 with a DMM.

Does the resistance measure greater than the specified value?

3 ohms

Go to Step 23

Go to Step 18

18

Test for an intermittent and for a poor connection at the ignition 1 relay location on the underhood fuse block. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Did you find a condition?

--

Go to Step 22

Go to Intermittent Conditions

19

Test for shorted terminals and poor connection at the ECM electrical connectors. Refer to Testing for Intermittent Conditions and Poor Connections and Micro .64 Connectors in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 25

Go to Step 24

20

Repair the short to ground in the ignition 1 voltage circuit between the underhood fuse block electrical connector and the ECM electrical connector. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 25

--

21

Repair the high resistance or an open in the ignition 1 voltage circuit between the underhood fuse block electrical connector and the ECM electrical connector. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 25

--

22

Replace the underhood fuse block. Refer to Underhood Electrical Center or Junction Block Replacement in Wiring Systems.

Did you complete the replacement?

--

Go to Step 25

--

23

Replace the ignition 1 relay. Refer to Relay Replacement in Wiring Systems.

Did you complete the replacement?

--

Go to Step 25

--

24

Replace the ECM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

Did you complete the replacement?

--

Go to Step 25

--

25

  1. Clear the DTCs with a scan tool.
  2. Turn OFF the ignition for 30 seconds.
  3. Turn ON the ignition, with the engine OFF.
  4. 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.

Did the DTC fail this ignition?

--

Go to Step 4

Go to Step 26

26

Observe the Capture Info with a scan tool.

Are there any DTCs that have not been diagnosed?

--

Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information

System OK