ISC, ISCe, QSC8.3, ISL, ISLe3, ISLe4 and QSL9 Engines – 010-029   Cold Starting Aid

General Information

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The cold starting aid is not a serviceable part.

If the cold starting aid has cracked, broken, or melted elements, the entire air intake manifold must be replaced. Refer to Procedure 010-023 in Section 10.

 
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ISC, ISL CM554 preheat/post-heat cycle information:

The intake air heaters are used in B and C engines to aid starting in cold ambient conditions. There are two phases of intake air heater operation:

  • Preheat (after key on and before cranking)
  • Post-heat (just after a successful engine start).

The intake air heater is used in starting during cold temperatures and to reduce white smoke after such a start.

The intake air heaters or grid heaters are energized or de-energized from two relays controlled by the ECM. The amount of time the intake air heaters stay on in the preheat phase is a function of the intake manifold temperature at key on; preheat time increases with colder intake manifold temperatures. The maximum duration of preheat is 45 seconds and no engine preheat is needed for coolant or intake air temperatures exceeding 4.4°C [40 °F] for ISC/ISL engines.

A “Wait-to-Start” lamp is also controlled by the ECM and is illuminated (to indicate that the driver must not crank the engine) while the intake air heaters are activated just after key on, during the preheat phase.

During cranking, the intake air heater is turned off to allow maximum current to be used by the starter. The post-heat cycle can operate for several minutes on very cold days before the intake air heaters are de-energized.

QSC, QSL CM554 preheat cycle information:

The preheat cycle of the electric intake heater varies by ambient temperature and is controlled by the ECM. During the preheat cycle, the ECM sends power to the OEM-supplied “Wait-to-Start” lamp. The operator must not crank the engine until the “Wait-to-Start” lamp is deactivated. Consult the Operation and Maintenance Manual for further details on start procedures. Figure 1 illustrates the intake heater preheat cycle.

Preparatory Steps

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 WARNING 

Batteries can emit explosive gases. To reduce the possibility of personal injury, always ventilate the compartment before servicing the batteries. To reduce the possibility of arcing, remove the negative (-) battery cable first and attach the negative (-) battery cable last.

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Remove

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NOTE: If the grid heater is to be removed for any length of time, apply tape over the hole to keep debris out of the air intake manifold.

Remove the intake air heater.

The intake heater is installed under the intake manifold cover on some engines. Use the following procedure if removing the intake manifold cover is required. Refer to Procedure 010-108 in Section 10.

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Clean and Inspect for Reuse

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Inspect the air intake manifold heater for plugging or soot build up. If plugged, check for the source; turbocharger, air compressor, temperature/pressure sensor, relay, and wiring harness.

Soot only covering individual elements is acceptable. Soot bridging the heating elements is not acceptable.

Replace the air intake manifold heater if necessary.

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Keep the gasket material and any other material out of the cylinder head intake manifold.

Clean the intake air heater sealing surfaces.

Clean the air intake manifold cover sealing surface.

Clean the air intake connection sealing surface.

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Install

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Install the grid heater.

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Finishing Steps

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 WARNING 

Batteries can emit explosive gases. To reduce the possibility of personal injury, always ventilate the compartment before servicing the batteries. To reduce the possibility of arcing, remove the negative (-) battery cable first and attach the negative (-) battery cable last.

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    Last Modified:  28-Jul-2010