2010 Cadillac CTS Sedan AWD V6-3.0L Page 1887

2010 Cadillac CTS Sedan AWD V6-3.0L Page 1887

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

P2156

DTC P2147, P2148, P2150, P2151, P2153, P2154, P2156, P2157, P216B, P216C, P216E, or P216F (w/LF1)

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.

* Review Strategy Based Diagnosis (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Strategy Based Diagnosis) for an

overview of the diagnostic approach.

* Diagnostic Procedure Instructions (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic Procedure

Instructions) provides an overview of each diagnostic category.

DTC Descriptors

DTC P2147

- Cylinder 1 Injector High Control Circuit Low Voltage

DTC P2148

- Cylinder 1 Injector High Control Circuit High Voltage