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P0442

Read the instructions below then start the fault diagnostic procedure.

Symptom: CHECK ENGINE. Possible smell of petrol.

P0442


EVAP. Small Leakage in System.


Fault symptoms


• CHECK ENGINE.

• Possible smell of petrol.


On-Board Diagnostics

Type of diagnosis:


- Once per driving cycle. Interrupted when fault criteria fulfilled or OK reported. Restarts next driving cycle.


Enable criteria:


- General conditions for this trouble code: When starting the engine, the atmospheric pressure must exceed 78 kPa and the engine coolant and intake air temperatures must exceed -7°C.

- Test 1: Starting coolant temperature lower than 40°C. Purge active. Idling. Max. one change in status of brake light switch. Purge adaptation higher than -7 %. Intake air pressure at least 20 kPa below atmospheric pressure. Car stationary for 5 s.

Diagnosis starts once the above conditions are fulfilled. If the diagnosis is interrupted, the speed must exceed 0 on one occasion before it is allowed to restart. Diagnosis then proceeds through phases A-C: A) Shut-off valve is activated simultaneously as purge is interrupted for 3.5 s. Meanwhile, the tank pressure is observed. B) EVAP purge valve pulse ratio set to 18% until tank pressure drops by 0.6 kPa, whereby purge is interrupted. The drop in pressure must take no longer than 20 s. If the pressure drops too rapidly during this phase, the diagnosis will be interrupted as there is too much fuel in the tank (more than 85%). C) Tank pressure is observed for max. 6 s.

- Test 2: Starting coolant temperature higher than 40°C or Test 1 indicated a leak. Accepted transition diagnosis of oxygen sensor 1. Purge active. Idling. Max. one change in status of brake light switch. Purge adaptation higher than -6 %. Intake air pressure at least 20 kPa below atmospheric pressure. Car stationary for 5 s.

Diagnosis starts once the above conditions are fulfilled. If the diagnosis is interrupted, the speed must exceed 0 on one occasion before it is allowed to restart. Diagnosis then proceeds through phases A-C: A) Shut-off valve is activated simultaneously as purge is interrupted for 3.5 s. Meanwhile, the tank pressure is observed. B) EVAP purge valve pulse ratio set to 18% until tank pressure drops by 0.6 kPa, whereby purge is interrupted. The drop in pressure must take no longer than 20 s. If the pressure drops too rapidly during this phase, the diagnosis will be interrupted as there is too much fuel in the tank (more than 85%). C) Tank pressure is observed for max. 6 s.


Fault criteria:


- If the pressure drops more than 0.25 kPa in phase A then an internal leak has been detected in the EVAP canister purge valve. If the pressure does not drop to 0.6 kPa within 20 s in phase B then a major leak has been detected. If the pressure rises too rapidly within 6 s in phase C then a minor leak has been detected.

- The trouble code is generated once fault criteria have been fulfilled during both Test 1 and Test 2 during the same driving cycle and dependents are OK.

P0441 for a fault during phase A. P0455 for a fault during phase B. P0442 for a fault during phase C.


Dependents:


- P0444, P0445, P0501, P0502, P0506, P0507, P1444, P1445, P1576 and P1577.


System reaction to a fault:


- If a leak is detected during Test 1 or Test 2, the message “TIGHTEN FUEL FILLER CAP” will be displayed on SID. The message is sent after each test that indicates a leak but not more than twice in succession. The diagnosis must first report OK on one occasion before the message can be sent again.


OK report:


- Test 1 or Test 2 performed once and fault criteria not fulfilled.


Fault handling: (See section Fault handling III, other emission-related components and functions for more information.)


- Type III.


Diagnostic help

Fault diagnosis concerns a leak.

Functions in the diagnostic tool related to the fault:


• Diagnostic status for the diagnosis.

• Activate EVAP diagnosis.


See also description of readings under "Read Values" menu for more information.

Note

To generate a trouble code, Test 1 must indicate a leak first and then Test 2 during the same driving cycle. Starting coolant temperature must be below 40°C (104°F) if this is to take place. The trouble code can therefore not be generated if the engine was warm when started.

During the final check of a rectified fault, the diagnostic tool activation command must be used so that Test 1 is initiated irrespective of starting temperature.