2010 Cadillac CTS Sedan AWD V6-3.6L Page 1137
ECM.
4. Install the fuse that supplies B+ to terminal 56-X2 of the K20 ECM.
5. Ignition ON, test for 4.8-5.2 V between the 5 V reference circuit terminal 11 and ground.
瀚慖f less than the specified range, test the 5 V reference circuit for a short to ground or an open/high resistance. If the circuit tests normal,
replace the K20 ECM.
瀚慖f greater than the specified range, test the 5 V reference circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.
6. Ignition ON, verify the scan tool Fuel Rail Pressure Sensor voltage parameter is greater than 4.96 V.
瀚慖f less than the specified value, test the signal circuit for a short to ground. If the circuit tests normal, replace the K20 ECM.
7. Connect a 3 A fused jumper wire between the signal circuit terminal 12 and the low reference circuit terminal 5. Verify the scan tool Fuel
Rail Pressure Sensor voltage parameter transitions from greater than 4.96 V to less than 0.02 V.
瀚慖f the parameter does not transition from the maximum to minimum value, test the signal circuit for an open/high resistance or a short to
voltage. If the circuit tests normal, replace the K20 ECM.
8. Ignition OFF, remove the intake manifold.
9. Connect the multi-way harness connector X117.
Note: Testing for steps 11 through 15 are performed at the fuel rail pressure sensor connector.
10. Disconnect the B47 fuel rail pressure sensor connector.
11. Remove the fuse that supplies B+ to terminal 56-X2 of the K20 ECM.
12. Ignition OFF, test for less than 5 ohm between the low reference circuit terminal 1 and ground.
瀚慖f greater than the specified range, test the low reference circuit for an open/high resistance.
13. Install the fuse that supplies B+ to terminal 56-X2 of the K20 ECM.
14. Ignition ON, test for 4.8-5.2 V between the 5 V reference circuit terminal 3 and ground.
瀚慖f less than the specified range, test the 5 V reference circuit for a short to ground or an open/high resistance.
瀚慖f greater than the specified range, test the 5 V reference circuit for a short to voltage.
15. Ignition ON, verify the scan tool Fuel Rail Pressure Sensor voltage parameter is greater than 4.96 V.
瀚慖f less than the specified value, test the signal circuit for a short to ground.
16. Connect a 3 A fused jumper wire between the signal circuit terminal 2 and the low reference circuit terminal 1. Verify the scan tool Fuel Rail
Pressure Sensor voltage parameter transitions from greater than 4.96 V to less than 0.02 V.
瀚慖f the parameter does not transition from the maximum to the minimum value, test the signal circuit for an open/high resistance or a short
to voltage.
17. If all circuits test normal, replace the B47 fuel rail fuel pressure sensor.
Repair Instructions
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.
* Fuel Pressure Sensor Replacement - Fuel Injection Fuel Rail (LF1) (See: Powertrain Management/Fuel Delivery and Air Induction/Fuel
Pressure Sensor/Switch/Service and Repair)Fuel Pressure Sensor Replacement - Fuel Injection Fuel Rail (LLT) (See: Powertrain
Management/Fuel Delivery and Air Induction/Fuel Pressure Sensor/Switch/Service and Repair)
* Control Module References (See: Testing and Inspection/Programming and Relearning) for ECM replacement, setup, and programming
P0193
DTC P0192 or P0193 (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.
* 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.
