2010 Cadillac CTS Sedan AWD V6-3.6L Page 1144
瀚慖f the test lamp is ON, test the high voltage control circuit for a short to voltage. If the circuit tests normal, replace the ECM.
10. Clear the DTC information with a scan tool, then cycle the ignition OFF.
11. Ignition OFF, connect a test lamp between the high voltage supply circuit terminal and the high voltage control circuit terminal of the
appropriate injector listed below.
* Fuel Injector 1 terminal 8 and terminal 2 X117
* Fuel Injector 2 terminal 2 and terminal 1 X116
* Fuel Injector 3 terminal 9 and terminal 3 X117
* Fuel Injector 4 terminal 4 and terminal 3 X116
* Fuel Injector 5 terminal 10 and terminal 4 X117
* Fuel Injector 6 terminal 6 and terminal 5 X116
12. Crank or start the engine while observing the test lamp. The test lamp should flash several times and then stop when the DTC sets.
瀚慖f the test lamp does not flash, test the high voltage control circuit for an open/high resistance. If the circuit tests normal, replace the
ECM.
Note: Testing for the following steps is performed on the fuel injector side of the multi-way harness connector. It may be necessary to
remove the intake manifold to isolate the condition.
13. Ignition OFF, measure the resistance between the appropriate high voltage supply circuit and ground. The DMM should display OL ohm.
瀚慖f less than the specified range, test the high voltage supply circuit and the high voltage control circuit for a short to ground. If the
circuits/connections test normal, test or replace the appropriate fuel injector(s).
14. Test for 1.5-2.5 ohm between the appropriate high voltage supply circuit and the high voltage control circuit.
瀚慖f less than the specified range, test for a short between the high voltage supply circuit and the high voltage control circuit. If the
circuits/connections test normal, test or replace the appropriate fuel injector(s).
瀚慖f greater than the specified range, test the high voltage supply circuit and the high voltage control circuit for an open/high resistance. If
the circuits/connections test normal, test or replace the appropriate fuel injector.
Component Testing
1. Remove the intake manifold and disconnect the appropriate fuel injector.
2. Verify the resistance of each fuel injector with one of the following methods:
* If the engine coolant temperature (ECT) sensor is between 10-32掳C (50-90掳F), the resistance of each fuel injector should be 1.25-1.75
ohm.
瀚慖f not within the specified range, replace the fuel injector.
* If the ECT sensor is not between 10-32掳C (50-90掳F), measure and record the resistance of each fuel injector with a DMM. Subtract the
lowest resistance value from the highest resistance value. The difference between the lowest value and the highest value should be equal
to or less than 0.45 ohm.
瀚慖f the difference is more than 0.45 ohm, add all of the fuel injector resistance values to obtain a total resistance value. Divide the total
resistance value by the number of fuel injectors to obtain an average resistance value. Subtract the lowest individual fuel injector
resistance value from the average resistance value. Compute the difference between the highest individual fuel injector resistance
value and the average resistance value. Replace the fuel injector that displays the greatest difference above or below the average.
Repair Instructions
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.
* Fuel Injector Replacement (See: Powertrain Management/Fuel Delivery and Air Induction/Fuel Injector/Service and Repair/Fuel Injector
Replacement)
* Control Module References (See: Testing and Inspection/Programming and Relearning) for ECM replacement, setup, and programming
P0202
DTC P0201-P0206, P0261, P0262, P0264, P0265, P0267, P0268, P0270, P0271, P0273, P0274, P0276, P0277, P2146, P2149, P2152, P2155,
P216A, or P216D (w/LLT)
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System
Check - Vehicle) prior to using this diagnostic procedure.
