If a customer complains that the engine malfunction indicator light, for the above-mentioned vehicle, is activated and the engine judders or accelerates poorly, the possible source of error could be the coolant temperature sensor. The following error codes may be stored: Error code `the same as`:
- P0122,`Throttle valve sensor, accelerator pedal sensor or switch A, signal is too low`.
- P0131,`Lambda sensor bank 1, signal is too low`.
A malfunction could be triggered by a leak inside the 2-pin coolant temperature sensor (which is installed in the electrical thermostat). It is also possible that cooling water has entered the wiring harness or the control unit through a capillary effect, causing problems in the electrics/electronics.
If during this inspection/visual check, water is detected in the wiring harness casing or oxidation is detected on the control unit and connectors, then the control unit must also be checked/replaced.
The coolant temperature sensor is available from the Hella spare part product range. Spare part no.: 6PT 009309-221
Before carrying out the repair it is recommended that you check the signals and the signal transmission for the accelerator pedal sensor, throttle valve sensor and lambda sensor with regard to the stored error codes, and that you then delete the error codes.
Important safety note
Technical information and practical tips have been compiled by HELLA in order to provide professional support to vehicle workshops in their day-to-day work. The information provided on this website is intended for use by suitably qualified personnel only.
Reprinting, distribution, reproduction, exploitation in any form or disclosure of the contents of this document, even in part, is prohibited without our express, written approval and indication of the source. The schematic illustrations, pictures and descriptions serve only for the purposes of explanation and representation of the instructions and cannot be used as a basis for installation or assembly work. All rights reserved.
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