97stratus auto shutdown system kickin in?

Tiny
KEV2NICE25
  • MEMBER
  • 1997 DODGE STRATUS
  • 4 CYL
  • FWD
  • AUTOMATIC
Have a 97 dodge stratus changed the timing belt its perfect and somthing is triggering the auto shut down system and grounding my spark at the coil
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have the same problem?
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No
Monday, January 31st, 2011 AT 8:46 PM

3 Replies

Tiny
CARADIODOC
  • EXPERT
By "triggering", do you mean the automatic shutdown relay is turning on or not turning on? If you measure the voltage on the dark green / orange wire in the coil pack connector, any of the injectors, or either small terminal on the back of the alternator, you should see 12 volts for just one second after turning on the ignition switch. That voltage should come back during engine cranking. If it does not, suspect a problem with the camshaft position sensor, crankshaft position sensor, or the timing belt is off by two or more teeth.

Also check for diagnostic fault codes. If you find one for "cam and crank sync", double-check the timing belt. If you have the single overhead cam engine, also check for a sheared off dowel pin between the camshaft and its sprocket.

Caradiodoc
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Monday, January 31st, 2011 AT 9:07 PM
Tiny
KEV2NICE25
  • MEMBER
I have voltage to to an from alternator I have voltage to the coil pack when cranking no spark out of coil have changer coil packs but same thing there is an auto shutdown relay this kicking in. While im cranking it I get no spark but when I stop cranking three sec. Later the auto relay clicks and I get one spark out of the coil
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Monday, January 31st, 2011 AT 9:43 PM
Tiny
CARADIODOC
  • EXPERT
Hmmm. This is definitely not common, but it sounds like the Engine Computer might be defective. The ASD relay is working correctly. When the computer gets pulses from the crankshaft position sensor and the camshaft position sensor, it turns on the ASD relay. That relay is what sends voltage to the coil pack, injectors, etc. When you stop cranking the engine, those sensor pulses stop, then the computer turns off the ASD relay as you heard it do.

Before you go looking for a computer, it might be a good idea to find a mechanic with the Chrysler DRB3 scanner to read live sensor data. In particular, it will list the cam and crank sensors as "no" or "present" while you're cranking the engine. If one is switching back and forth, you may just have a bad sensor. All it takes is one weak pulse every couple of seconds to keep the ASD relay turned on, but that's not sufficient to fire a coil. Some aftermarket scanners will read those sensors too.

As for that one spark, the computer keeps the coil grounded so it builds up a nice big magnetic field, then when the pulses come from the sensors, the computer switches the ground side open to stop current flow. The rapidly collapsing magnetic field is what induces the very high voltage to the spark plug. When you stop cranking the engine, the ASD relay turning off also breaks the circuit, (the feed side instead of the ground side, but that doesn't matter), so the magnetic field collapses again and makes that one spark. That tells us the computer is not switching the ground side and is why there isn't any spark from the coil during cranking.

Caradiodoc
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Monday, January 31st, 2011 AT 11:09 PM

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