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Chery SQR7160 series sedan ABS system-fault diagnostic and repairing
4. Intermittent Fault Repair Precaution In electronic controlled system, instantaneous contact problem at circuit or signal input & output area may occur, causing intermittment fault or fault code set during ECU self-check. If symptom continuously exists, determine defective part referring to FAULT W/CODE DIAGNOSTIC CHART. The problem is hard to locate beacue fault source may disappear at some time.
In such cases, simulate following condition and check if problem occurs again:
I. When viabrating is the main possible causes: * Slightly wiggle connector; * Slightly wiggle wiring harness; * Slightly shake sensor; * Slightly shake other moving parts (wheel bearing).
Note: Replace with a new part when wiring harness is broken for high tension, especially for a temporary sensor short or open causing by suspension system moving up and down when vehicle operating, therefore a vehicle drive test is must when check sensor signal.
Ⅱ.When overheat or overcold is the main possible causes:
* Dry suspected part with a drier; * Check if there is a cold welding condition using cold spraying agent.
Ⅲ. When over circuit contact resistance is the main possible cause: * Turn on all accessories including headlight and rear defrost switch.
If the problem does not occur again, diagnose it till the problem occurs next time. In most cases, intermittent fault will be worse and will not get better.
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