Impco HHI, Руководство по обслуживанию

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41
INTERMITTENT
Checks Action
DEFINITION: The problem may or may not turn ON the (MIL) or store a Diagnostic Trouble Code (DTC).
Preliminary Checks
Do not use the DTC tables. If a fault is an intermittent, the use of the DTC
tables with this condition may result in the replacement of good parts.
Faulty Electrical Con-
nections or Wiring
Faulty electrical connections or wiring can cause most intermittent problems.
Check the suspected circuit for the following conditions:

Faulty fuse or circuit breaker, connectors poorly mated, terminals not fully
seated in the connector (backed out). Terminals not properly formed or
damaged.

Wire terminals poorly connected.

Terminal tension is insufficient.

Carefully remove all the connector terminals in the problem circuit in or-
der to ensure the proper contact tension.

If necessary, replace all the connector terminals in the problem circuit in
order to ensure the proper contact tension (except those noted as “Not
Serviceable”). See section
Wiring Schematics .

Checking for poor terminal to wire connections requires removing the
terminal from the connector body.
Operational Test
If a visual and physical check does not locate the cause of the problem, op-
erate the vehicle with the DST connected. When the problem occurs, an
abnormal voltage or scan reading indicates a problem circuit.
Intermittent MIL
Illumination
The following components can cause intermittent MIL and no DTC(s):

A defective relay.

Switch that can cause electrical system interference. Normally, the prob-
lem will occur when the faulty component is operating.

The improper installation of add on electrical devices, such as lights, 2-
way radios, electric motors, etc.

The ignition secondary voltage shorted to a ground.

The MIL circuit or the Diagnostic Test Terminal intermittently shorted to
ground.

The MIL wire grounds.
Loss of DTC Memory
To check for the loss of the DTC Memory:
1. Disconnect the TMAP sensor.
2. Idle the engine until the MIL illuminates.
3. The ECM should store a TMAP DTC which should remain in the memory
when the ignition is turned OFF. If the TMAP DTC does not store and
remain, the ECM is faulty.