5/38121

Fault code 5/38121





Malfunction indicated
Mass air flow sensor, hot wire (filament) burn-off function out of order.

Fault symptom
Starting difficulty, poor driveablity and high fuel consumption
CHECK ENGINE lamp alight.

Test procedure

If fault code 2/45691 occurs at the same time, it is advisable to deal with that fault code first.

1 With the connectors unplugged from the control module and mass air flow sensor, check the RD/WH lead between pin 8 of the control module and pin 4 of the mass air flow sensor.

2 With the connectors plugged in and the ignition switch in the Drive position, check that battery voltage is present on pin 5 of the mass air flow sensor and that pin 1 is properly grounded.

If no voltage is present, check the BN/WH and GN/WH leads between pin 5 of the mass air flow meter and pin 87B of the main relay.

If grounding is not OK, check the BK lead between pin 1 of the mass air flow sensor and grounding point G7 on the intake pipe.

3 If the fault persists fit a new mass air flow sensor, clear the fault code memory and take the car out on a road test. Afterwards check whether the fault code is generated afresh.

4 If the fault code is generated afresh after fitting a new mass air flow sensor, fit the old one back in place again and try a new LH control module instead.