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
| • | The ignition is ON. |
| • | Ignition voltage is greater than 8 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.
Conditions for Clearing the DTC
The condition for setting the DTC is no longer present and the DTC is cleared with a scan tool.
Reference Information
Schematic Reference
Connector End View Reference
Exhaust System Connector End Views
Electrical Information Reference
Scan Tool Reference
Scan Tool Data List for exhaust tail pipe flow valve control module
Circuit/System Testing
- Ignition OFF, disconnect the exhaust tail pipe flow control valve solenoid connector.
- Ignition ON, measure for 0 volts between the exhaust tail pipe flow control valve solenoid supply voltage circuit and ground.
- Ignition ON, use scan tool to command exhaust flow control relay ON, measure for 10 volts or above between the exhaust tail pipe flow control valve solenoid supply voltage circuit and ground.
- If all circuits test normal replace the exhaust tail pipe flow valve control module.
| ⇒ | If over 0 volts, test for short to voltage in exhaust valve solenoid supply voltage circuit. |
| ⇒ | If under 10 volts, test for short to ground in exhaust valve solenoid supply voltage circuit. |
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
