IQA (Injector Quantity Adjustment) means adjusting fuel injection quantity difference between injectors which occurs inevitably at manufacturing process as allotting serial number consists of 7 letters to each injectors.
Inputting IQA code of injectors installed in each cylinder to ECM, ECM recognizes the fuel injection quantity difference between each injectors. ECM adjusts every injector to have same fuel injecting characteristic as recognizing specific fuel injection map which is different for each serial number.
P1670 is set when ‘IQA input error’ or ‘saving error’ occurs in EEP ROM where IQA data is saved. This code is due to ECM internal error.
Item | Detecting Condition | Possible Cause | ||
DTC Strategy | ● EEP ROM monitoring | ● ECM internal error | ||
Enable Conditions | ● IG KEY "ON" | |||
Threshold Value | ● Input error, saving error occurs at injector IQA code inputting. | |||
Diagnostic Time | ● Immediately | |||
Fail Safe | Fuel Cut | NO | ● Engine Check Lamp blinks. | |
EGR Off | NO | |||
Fuel Limit | NO | |||
Check Lamp | YES |
Check injector class input state
IG KEY "OFF", ENGINE "OFF".
Using GDS, select "ENGINE CONTROL" - "INJECTOR CORRECTION".
Check currently inputted "injector class input state".
Specification : IQA data inputted to ECM should be identical with IQA data of injector.
Are both data identical?
![]() | ▶ Go to "Verification of Vehicle Repair". |
![]() | ▶ If error is not corrected after reperforming "INJECTOR CORRECTION" procedure, replace ECM. |
Input IQA data of injector mounted at cylinder at replacing ECM using GDS.
If this process is not performed, engine check lamp on cluster blinks and normal engine power generation is impossible.
After a repair, it is essential to verify that the fault is corrected.
After connecting GDS select "Diagnostic Trouble Codes(DTCs)" mode to and then clear DTC.
Drive the vehicle within DTC Enable conditions in General information.
After selecting "Diagnostic Trouble Codes(DTCs)" mode and check DTC is recorded again.
Are any DTCs recorded ?
![]() | ▶ Go to the DTC guide of recorded NO. in GDS |
![]() | ▶ System operates within specification. |