2010 Cadillac CTS Sedan AWD V6-3.6L Page 1206
7. Connect a 3 A fused jumper wire between the 5 V reference circuit terminal E and the TP sensor 1 signal circuit terminal D. Verify the scan
tool Throttle Position Sensor 1 voltage parameter is greater than 4.89 V.
瀚慖f less than the specified value, test the signal circuit for an open/high resistance or for a short to ground. If the circuit tests normal,
replace the Engine Control Module.
8. Verify the scan tool Throttle Position Sensor 2 voltage parameter is greater than 4.97 V.
瀚慖f less than the specified value, test the signal circuit terminal F for a short to ground. If the circuit tests normal, replace the Engine
Control Module.
Note: If the fuse in the jumper wire opens, the signal circuit is shorted to a voltage.
9. Connect a 3 A fused jumper wire between the TP sensor 2 signal circuit terminal F and the low reference circuit terminal C. Verify the scan
tool Throttle Position Sensor 2 voltage parameter is less than 0.10 V.
瀚慖f greater than the specified value, test the signal circuit for an open/high resistance or for a short to voltage. If the circuit tests normal,
replace the Engine Control Module.
10. If all circuits test normal, replace the throttle body assembly.
Repair Instructions
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.
* Throttle Body Assembly Replacement (LF1) (See: Powertrain Management/Fuel Delivery and Air Induction/Throttle Body/Service and
Repair/Removal and Replacement)Throttle Body Assembly Replacement (LLT) (See: Powertrain Management/Fuel Delivery and Air
Induction/Throttle Body/Service and Repair/Removal and Replacement)
* Control Module References (See: Testing and Inspection/Programming and Relearning) for Engine Control Module replacement, setup, and
programming
P228C
DTC P0089, P00C6, P228C, or P228D (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 P0089
- Fuel Pressure Regulator Performance
DTC P00C6
- Fuel Rail Pressure Low During Engine Cranking
DTC P228C
- Fuel Pressure Regulator 1 Control Performance - Low Pressure
DTC P228D
- Fuel Pressure Regulator 1 Control Performance - High Pressure
Circuit/System Description
The fuel rail pressure sensor detects fuel pressure within the fuel rail. The engine control module (ECM) provides a 5 V reference voltage on the 5
V reference circuit and ground on the low reference circuit. The ECM receives a varying signal voltage on the signal circuit.
High pressure fuel is regulated by the high pressure fuel pump actuator, which is a part of the high pressure fuel pump. The high pressure fuel pump
actuator is a solenoid valve. The ECM provides a voltage on the actuator high control circuit and ground on the actuator low control circuit. Both
circuits are controlled through output drivers within the ECM. When deactivated, both drivers are disabled. When activated, the high control circuit
driver energizes the high pressure fuel pump actuator and the low control circuit driver pulse-width modulates (PWM) the low control circuit to
