The engine controls ignition relay or MAIN relay is controlled by the engine control module (ECM) depending upon input from the ignition switch. Battery positive voltage is supplied to the relay coil and switch. When the ignition switch is turned to the ON position, the ECM will provide ground on the control circuit of the relay using a low side driver. This will allow voltage through the relay switch contacts to the components. The ECM monitors the voltage level on the control circuit of the relay. If the ECM detects an open or short to ground on the control circuit of the relay, DTC P1611 sets.
This diagnostic procedure supports the following DTC:
DTC P1611 Engine Controls Ignition Relay Control Circuit Low Voltage
• | The ignition is ON or the engine is operating. |
• | DTC P1611 runs continuously once the above condition is met. |
The ECM detects an open or short to ground on the control circuit of the relay.
• | The malfunction indicator lamp (MIL) will not illuminate. |
• | The ECM will record operating conditions at the time the diagnostic fails. This information will be stored in the Freeze Frame and Failure Records buffers. |
• | Using the scan tool can clear DTCs. |
• | Disconnect the ECM battery feed for 10 seconds. |
• | For an intermittent condition, refer to Intermittent Conditions . |
• | The following table illustrates the MAIN relay terminal location in the underhood fuse block: |
MAIN Relay Terminal Identification | |
---|---|
Feedback | B+ - Coil |
Control | B+ - Switch |
Front of Vehicle |
The numbers below refer to the step numbers on the diagnostic table.
This step tests the control circuit for a shorted to voltage.
This step tests the control circuit for an open.
This step tests the control circuit for high resistance.
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 - Engine Controls? | -- | Go to Step 2 | |||||||
2 |
Do you hear an audible click from the relay? | -- | Go to Step 4 | Go to Step 3 | ||||||
3 |
Did the DTC fail this ignition? | -- | Go to Step 4 | Go to Diagnostic Aids | ||||||
4 |
Does the test lamp illuminate? | -- | Go to Step 5 | Go to Step 12 | ||||||
Does the test lamp illuminate? | -- | Go to Step 9 | Go to Step 6 | |||||||
Does the test lamp illuminate? | -- | Go to Step 7 | Go to Step 9 | |||||||
7 |
Is the resistance less than the specified value? | 3 ohms | Go to Step 8 | Go to Step 12 | ||||||
Important: Use a test lamp that measures between 25-30 ohms. Is the voltage less than the specified value? | 2.5 V | Go to Step 10 | Go to Step 9 | |||||||
9 | Test the control circuit of the MAIN relay for one of the following conditions:
Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 15 | Go to Step 11 | ||||||
10 | Test for shorted terminals and poor connections at the ENGINE relay. Refer to Testing for Intermittent Conditions and Poor Connections and Repairing Connector Terminals in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 15 | Go to Step 13 | ||||||
11 | Test for shorted terminals and poor connections at the engine control module (ECM). Refer to Testing for Intermittent Conditions and Poor Connections and Repairing Connector Terminals in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 15 | Go to Step 14 | ||||||
12 | Repair an open or high resistance in the battery positive voltage circuit of the MAIN relay coil. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 15 | -- | ||||||
13 | Replace the MAIN relay. Did you complete the replacement? | -- | Go to Step 15 | -- | ||||||
14 | Replace the ECM. Refer to Engine Control Module Replacement . Did you complete the replacement? | -- | Go to Step 15 | -- | ||||||
15 |
Did the DTC fail this ignition? | -- | Go to Step 2 | Go to Step 16 | ||||||
16 | Are there any DTCs that have not been diagnosed? | -- | System OK |