P0236

P0236
Turbocharger Boost Sensor Circuit "A" - Range / Performance Waste Gate Frequency Valve faulty

Function
The Waste Gate Frequency Valve receives a pulse width modulated ground signal from the Engine Control Module (ECM). Depending on the duration of the period, a frequency ratio of 0% to 100% results. The Waste Gate Frequency Valve pneumatically operates two pressure membrane boxes that operate the two waste gates via a linkage.

Diagnostic conditions
A fault is recognized and stored in memory when the engine speed is above 80 1/min and the battery voltage is between 7.5 and 17 Volt.





Wiring Diagram.









Diagnostic procedure
Check voltage supply to waste gate frequency valve.
1. Remove ECM relay.
2. Bridge terminals 30 and 87
3. Remove waste gate frequency valve connector.
4. Connect voltmeter to pin 1 (plus) and ground. Specified value: battery voltage.

Check resistance of waste gate frequency valve.
1. Remove connector of waste gate frequency valve.
2. Connect ohmmeter to waste gate frequency valve, pins 1 and pin 2. Specified value: 28 - 32 ohms at 20°C.

Check wiring from ECM to waste gate frequency valve for continuity.
1. Remove waste gate frequency valve connector.
2. Remove ECM connector.
3. Connect ohmmeter to ECM connector, pin 57 and waste gate frequency valve connector, pin 2. Specified value: 0 - 5 ohms.

- If meter reads infinite resistance, check connector X 60, pin 4.

Check wiring from ECM to waste gate frequency valve for short to ground.
1. Remove connector for waste gate frequency valve.
2. Remove ECM connector.
3. Connect ohmmeter to ECM connector, pin 57 and ground. Specified value: infinite resistance.

- If meter reads 0 - 5 ohms, check wiring harness for chafing and pinching damage.

Check wiring from ECM to waste gate frequency valve for short to 6+.
1. Remove connector for waste gate frequency valve.
2. Remove ECM connector.
3. Switch ignition on.
4. Connect voltmeter to ECM connector, pin 57 and ground. Specified value: 0 Volt.

- If meter reads battery voltage, check wiring harness for chafing and pinching damage.