The powertrain 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 (ODM). When the ECM commands the powertrain relay ON, ignition 1 voltage is supplied to the ECM through the ECM 2 fuse in the underhood fuse block. The ignition 1 voltage input to the ECM provides the ignition power for the throttle actuator control (TAC) circuitry, and is also used to confirm that the powertrain relay has closed. This DTC will set when the ECM detects more than 2 volts on the ignition 1 voltage circuit to the ECM, after the ignition switch is turned OFF. DTC P0690 indicates a short to battery positive voltage in the ignition 1 voltage circuit to the ECM.
This diagnostic procedure supports the following DTC:
DTC P0690 Engine Controls Ignition Relay Feedback Circuit High Voltage
• | The battery voltage is between 9-16 volts. |
• | The ignition switch is turned OFF. |
• | The powertrain relay has been commanded OFF. |
The ECM detects greater than 2 volts on the ECM 2 ignition 1 voltage circuit for more than 2 seconds.
• | The control module stores the DTC information into memory when the diagnostic runs and fails. |
• | The malfunction indicator lamp (MIL) will illuminate. |
• | The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in Failure Records. |
• | The driver information center, if equipped, may display a message. |
• | A current DTC, last test failed clears when the diagnostic runs and passes. |
• | A history DTC clears 40 consecutive warm-up cycles, if no other failures are reported by this or any other emission related diagnostic. |
• | Clear the DTC with a scan tool. |
Step | Action | Yes | No | ||||||||||||
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Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Control Module Connector End Views and 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 |
Did the DTC fail this ignition? | Go to Step 3 | Go to Intermittent Conditions | ||||||||||||
3 |
Does the test lamp illuminate on either test point of the fuse? | Go to Step 4 | Go to Step 6 | ||||||||||||
4 |
Does the test lamp illuminate on either test point of the fuse? | Go to Step 5 | Go to Step 9 | ||||||||||||
5 |
Notice: Refer to Test Probe Notice in the Preface section.
Does the test lamp go out when a fuse is removed? | Go to Step 10 | Go to Step 13 | ||||||||||||
6 | Measure the resistance from terminal #30, of the powertrain relay to terminal #87 with a DMM. Refer to Troubleshooting with a Digital Multimeter in Wiring Systems. Does the DMM display OL? | Go to Step 7 | Go to Step 11 | ||||||||||||
7 | Measure the resistance from terminal #30, of the powertrain relay to terminal #85 with a DMM. Refer to Troubleshooting with a Digital Multimeter in Wiring Systems. Does the DMM display OL? | Go to Step 8 | Go to Step 11 | ||||||||||||
8 | Measure the resistance from terminal #85, of the powertrain relay to terminal #87 with a DMM. Refer to Troubleshooting with a Digital Multimeter in Wiring Systems. Does the DMM display OL? | Go to Intermittent Conditions | Go to Step 11 | ||||||||||||
9 | Test for shorted terminals and poor connections at the ECM electrical connector, and the ECM wire harness electrical connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 14 | Go to Step 12 | ||||||||||||
10 | Repair the short to battery positive voltage in the ignition 1 voltage circuit, which caused the test lamp to go out when the fuse for that circuit was removed. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 14 | -- | ||||||||||||
11 | Replace the powertrain relay. Refer to Relay Replacement in Wiring Systems. Did you complete the replacement? | Go to Step 14 | -- | ||||||||||||
12 | 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 14 | -- | ||||||||||||
13 | 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 14 | -- | ||||||||||||
14 |
Did the DTC fail this ignition? | Go to Step 3 | Go to Step 15 | ||||||||||||
15 | 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 |