P0443,P0444, P0445

/ 900 / 1996 / 2. Engine / Trionic OBDII / Fault diagnosis, diagnostic trouble codes / P0443,P0444, P0445

Symptom: CHECK ENGINE lamp (MIL) on. Any other diagnostic trouble codes (closed loop, misfiring)

P0443 , P0444 , P0445

Evap canister purge valve

Symptom of fault

CHECK ENGINE lamp (MIL) on. Any other diagnostic trouble codes (closed loop, misfiring)

Conditions

Purge valve active

P0443: All-embracing DTC.

P0444: Open circuit for more than 2 seconds.

P0445: Short circuit to ground for more than 2 seconds.

Diagnostic help

The purge valve can be activated with the ISAT scan tool.

Select "ACTIVATE".

Select "EVAP VALVE".

The valve is activated for 10 seconds at a frequency of 8 Hz 50%%. The valve clicks when activated.

Checking the wiring. Intermittent faults may occur as a result of occasional short circuits and breaks in the wiring. Jiggle the leads and in-line connectors at several places and in different directions to reveal faults in the wiring harness. Observe the multimeter, ISAT scan tool or test lamp while carrying out this check.

Diagnostic procedure

1. Check the resistance of the valve

Unplug the purge valve's 2- pin connector.

Take a resistance reading across pins 1 and 2 of the valve.

The reading obtained should be 26±3 ohms.

Is the resistance reading correct?

yes

Continue with point 2.

Change the valve and proceed to point 4.

2. Check the valve's power supply

Start the engine and run it at idling speed.

Connect the test lamp to pin 1 of the female connector and battery negative (B-).

The test lamp should light up.

Is the test lamp on?

yes

Continue with point 3.

Repair or replace the lead between pin 1 and crimped connection J67 and continue with point 4.

3. Check the valve's ground connection

Check the lead between pin 2 of the purge valve and pins 21 and 27 of the control module.

Is the wiring OK?

yes

Change the EVAP canister purge valve and continue with point 4.

Rectify the fault and proceed to point 4.

4. Final check

Clear the diagnostic trouble code.

Perform a driving cycle:

•

Start the engine and run it at idling speed until the temperature of the coolant rises above 60°C (140°F), or for at least 1 minute.

•

Drive the car for 5 minutes at varying engine rpm and loads.

Evaluation of the driving cycle:

Check whether the diagnostic trouble code has recurred.

Has the diagnostic trouble code recurred?

yes

Proceed to .

The remedial measure taken was correct.