P0380 Intake Air Heater Relay #1 Control Circuit

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DTC P0380: INTAKE AIR HEATER RELAY #1 CONTROL CIRCUIT

Monitor & Set Conditions

Intake air heater relay No. 1 control circuit is monitored with ignition on. DTC may be stored if Engine Control Module (ECM) does not detect that intake air heater turned on within one second of ignition being turned on.

Possible Causes

  • DTC Equal To Freeze Frame
  • Intake Air Heater Relay #1 Control Circuit Shorted To Ground
  • Open Ground Circuit
  • Intake Air Heater Relay #1 Control Circuit Open
  • Intake Air Heater Relay #1 Control Circuit Shorted To Voltage
  • Intake Air Heater Relay #1
  • ECM Driver

Testing

1. Turn ignition on with engine off. Using DRBIII(R) scan tool, check for DTCs. If Good Trip Counter for the specific DTC is displayed and not equal to zero, go to next step. If Good Trip Counter for the specific DTC is displayed and equal to zero, go to step 5 .

2. Using scan tool, determine if DTC matches FREEZE FRAME DTC. If DTC is equal to FREEZE FRAME DTC, go to next step. If DTC is not equal to FREEZE FRAME DTC, freeze frame DTC is a higher priority DTC and should be diagnosed before diagnosing DTC P0341. See DIAGNOSTIC TROUBLE CODE DEFINITIONS .

3. Ensure ignition is on with engine off. Using scan tool, read FREEZE FRAME data. Road test vehicle under conditions displayed in FREEZE FRAME data parameters and pay particular attention to DTC setting conditions such as speed, temperature and load. Using scan tool, check for DTCs. If the GOOD TRIPS counter for the specific DTC changed to zero, go to step 5 . If the GOOD TRIPS counter for the specific DTC did not change to zero, go to next step.

4. Ensure ignition is on with engine off. Using DVOM, check and record voltage across battery terminals. Continue monitoring battery voltage while using scan tool to briefly actuate intake air heater No. 1. DO NOT actuate intake air heater No. 1 for any longer than possible, as intake air heater draws a large amount of current. Stop actuation of intake air heater No. 1. If battery voltage drops less than .5 volt when intake air heater No. 1 is actuated, go to next step. If battery voltage drops .5 volt or greater when intake air heater No. 1 was actuated, intake air heater relay No. 1 is operating properly. Test is complete.

5. Turn ignition off. Disconnect connector containing intake air heater relay No. 1 control circuit (Yellow/Black wire). Intake air heater relays are located on bracket near driver's side battery. Disconnect ECM harness connector. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. Check for poor connection/terminal contact at ECM harness connector. Repair as necessary. Using DVOM, measure resistance between ground and terminal No. 29 (Yellow/Black wire) on ECM connector. If resistance is 1000 ohms or greater, go to next step. If resistance is less than 1000 ohms, repair short to ground in Yellow/Black wire between ECM and intake air heater relay No. 1.

6. Ensure ignition is off. Disconnect connector containing intake air heater relay No. 1 ground circuit (Black/Tan wire). Connect a test light between battery voltage and intake air heater relay No. 1 ground circuit (Black/Tan wire). If test light illuminates brightly, go to next step. If test light does not illuminate brightly, repair open or high resistance in Black/Tan wire between intake air heater relay No. 1 and ground connection. Ground connection is located at ground connection for negative battery terminal.

7. Ensure ECM harness connector and connector containing intake air heater relay No. 1 control circuit (Yellow/Black wire) are still disconnected. Using DVOM, measure resistance of Yellow/Black wire between intake air heater relay No. 1 and terminal No. 29 on ECM harness connector. If resistance is less than 10 ohms, go to next step. If resistance is 10 ohms or greater, repair open or high resistance in Yellow/Black wire between intake air heater relay No. 1 and ECM.

8. Ensure ECM harness connector and connector containing intake air heater relay No. 1 control circuit (Yellow/Black wire) are still disconnected. Turn ignition on. Using DVOM connected to ground, measure voltage at terminal No. 29 (Yellow/Black wire) on ECM harness connector. If voltage is less than one volt, go to next step. If voltage is one volt or greater, repair short to voltage in Yellow/Black wire between intake air heater relay No. 1 and ECM.

9. Turn ignition off. Reconnect ECM harness connector. Turn ignition on. Connect a test light between ground and intake air heater relay No. 1 control circuit (Yellow/Black wire). Using scan tool, actuate intake air heater No. 1 while observing test light. If test light turns on and off with each scan tool actuation, replace intake air heater relay No. 1. See appropriate REMOVAL, OVERHAUL & INSTALLATION article. If test light does not turn on and off with each scan tool actuation, replace and program ECM. See appropriate REMOVAL, OVERHAUL & INSTALLATION article.