DIAGNOSTIC TROUBLE CODE (DTC) - P1610 MAIN RELAY HIGH VOLTAGE

 

Know your Circuit

  • The principal relay will be grounded to ECM internal ground by ECM controlling, the moment the ignition switch is turned to ON.
  • If the voltage plummets to a level below a calibrated value a system voltage Diagnostic Trouble Code (DTC) will automatically be set

 

Pre-requisites for setting the DTC

 

  • This DTC can be housed in "key-on" status.
  • Main relay wiring harness is in high voltage.

 

What happens when DTC sets?

When will DTC clear?

1) The Malfunction Indicator Lamp (MIL) will start to glow.

 

1) The MIL will turn off automatically after four consecutive ignition cycles in which the diagnostic will perform flawlessly.

 

2) The ECM will record operating conditions when the diagnostic fails which will be stored in the Freeze Frame and failure records will buffer

2) A history DTC will clear after 40 consecutive warm up cycles without a fault.

 

3) A history DTC is stored

3) DTC(s) can be cleared with the aid of a Scan Tool.

 

 

Diagnostic Tools

  • Inspect harness connectors for the following:

                1) backed-out terminals

                2) Improper mating

                3) Broken locks

                4) Improperly formed or damaged terminals, and

                5) Poor terminal-to-wire connection at the ECM.

 

  • Also examine the wiring harness for damage.
  •  If the harness is undamaged then note the A/C pressure exhibited on the scan tool while moving the connectors and wiring harnesses associated to the ACP sensor.
  •  The location of the fault can be estimated if there is any change in the A/C pressure display.
  •  Scrutinizing the Fail Records vehicle mileage at the time the diagnostic test last failed may help understand the frequency in the condition that caused the DTC to set if DTC P1610 cannot be duplicated. This may assist in diagnosing the condition.

                                      

                                       SUMMARY OF STEPS TO BE UNDERTAKEN

                                      

DTC P1610 - Main Relay High Voltage

Step

Process

R         E       S   

U      L      T

1

 

Carry out an EOBD System Check.

Task Over?

IF YES

 THEN

 Follow Step 2

IF NO

 THEN 

Go to "On-Board Diagnostic System Check"

2

  1. Disconnect the main relay.
  2. Measure and note the resistance between main relay terminals 85 and 86.

Note: the value at this point ranges between 75 to 85 ?

Do you see that the resistance is within the specified value?

IF YES THEN Follow Step 3

IF NO

 THEN

 Follow Step 6

3

  1. Turn on the ignition switch to LOCK.
  2. Examine the ignition feed circuit, at terminal 85 in the relay harness connector keeping the test light, connected to ground.

Does the test light illuminate?

IF YES

 THEN

 

 

 

 

Follow Step 4

IF NO

 THEN

 

 

 

 

Go to "Diagnostic Tools"

4

  1. Again turn the ignition switch to LOCK mode.
  2. Remove the ECM wiring harness connector.
  3. Examine the ignition feed circuit, at terminal 85 in the relay harness connector keeping the test light, connected to ground.

Do you see the test light glowing?

IF YES

 THEN

Follow Step 5

IF NO

 THEN

Follow Step 7

5

Correct a high voltage between the ECM wiring connector terminal 7 and main relay terminal 85.

Task Over?

IF YES

 THEN

 Follow Step 7

-

6

Change the main relay.

Is the change done?

IF YES

 THEN

 Follow Step 7

-

7

  1. Clear the Diagnostic Trouble Codes(DTCs) taking a Scan Tool.
  2. Start the engine and idle at normal operating temperature.
  3. Run  the vehicle within the conditions stated for setting this DTC as mentioned in the supporting text.

Does the scan tool indicate that this diagnostic has been run and passed?

IF YES

 THEN

 Follow Step 8

IF NO

 THEN

Follow Step 2

8

Check if any additional DTCs are set.

Are there any undiagnosed DTCs shown?

Go to applicable DTC table

The System is operating fine