Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
DTC Descriptor
DTC P166A: Exhaust Control Valve Control CircuitDiagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Exhaust Valve Solenoid Supply Voltage | P166A | 1 | P166A | -- |
Ground | 1 | 1 | 1 | -- |
1. Exhaust Vibration/Noise - Exhaust Flow Control System Malfunction | ||||
Circuit/System Description
Exhaust tail pipe flow valve control module receives throttle position sensor and RPM information via serial data from powertrain control module (PCM). The exhaust tail pipe flow valve control module uses this information to determine if to command exhaust tail pipe flow control valve solenoid ON or OFF. When commanded OFF the exhaust tail pipe flow control valve solenoid allows vacuum to flow to close exhaust valve.
Conditions for Running the DTC
| • | Ignition ON. |
| • | Ignition voltage is greater than 10 volts. |
Conditions for Setting the DTC
| • | Exhaust tail pipe flow valve control module detects short to voltage on exhaust valve solenoid supply voltage circuit. |
| • | Exhaust tail pipe flow valve control module detects short to ground on exhaust valve solenoid supply voltage circuit. |
Action Taken When the DTC Sets
| • | Exhaust flow control valve defaults to open. |
| • | A DIC message and/or a warning indicator may be displayed. |
Conditions for Clearing the DTC
| • | The condition for setting the DTC is no longer present. |
| • | The history DTC is cleared when a current DTC is not detected in 100 consecutive drive cycles. |
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Exhaust Tail Pipe Flow Control System Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Testing
- Ignition OFF, disconnect the exhaust tail pipe flow control valve solenoid connector.
- Test for less than 5 ohms between the ground circuit terminal 1 and ground.
- Connect a test lamp between the supply voltage circuit terminal 2 and ground.
- Ignition ON, command the exhaust flow control relay ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.
- If all circuits test normal, replace the exhaust tail pipe flow valve solenoid. If the DTC resets, replace the exhaust tail pipe flow valve control module.
| ⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. |
| ⇒ | If the test lamp is always ON, test the supply voltage circuit for a short to voltage. If the circuit tests normal, replace the exhaust tail pipe flow valve control module. |
| ⇒ | If the test lamp is always OFF, test the supply voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace exhaust tail pipe flow valve control module. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for exhaust tail pipe flow valve control module replacement, setup, and programming |
