CHEROKEE：The Automatic Shut Down relay >2:Cherokee:

CHEROKEE：The Automatic Shut Down relay >2 - 車QF - Yahoo!ブログ

2009/5/31(日) 午後 4:35

11-06-2007, 03:53 PM #1
whitejeep96zj
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ASD relay...what triggers it.
So my jeep has just started to die randomly all of the sudden. I thought it was fuel so i gauged it and it stays at 48 psi all the time. I have used voltmeters on all the sensors and they are all in the right range. So i was wondering what triggers the asd relay to kill the car because i was told when i got it that the security system has triggered it a couple of times even though the car was unlocked using the key. Thanks.
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11-06-2007, 04:16 PM #2
greasefingers
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iTrader Rating Sounds to me the security system may be suspect?

The computer (ecu or pcm) triggers the relays by grounding them

Electrical trouble-shooting can be a biotch. I have spent several cold winter nights on my back under cars with flood lights and propane heaters. Hint: you need a stock of hot chocolate and a warm women waiting inside your house!

If you test the circuit for battery with the key in the On/Run position; then you only have about 3 seconds before the PCM times out. This is because the PCM needs a Cam & crank shaft signal. If it does not see these then it de-energizes the ADS relay (automatic shutdown relay). The ADS relays powers the fuel pump relay. The relays will make a clunk when energized. However this is not true when power is removed from them! They have a soft return. I place a finger on each the two relays when I want to see if power is getting to them. That way you are fooled by other neighbouring relays in there.
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11-06-2007, 06:32 PM #3
whitejeep96zj
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Quote:Originally Posted by greasefingers
Sounds to me the security system may be suspect?

The computer (ecu or pcm) triggers the relays by grounding them

Electrical trouble-shooting can be a biotch. I have spent several cold winter nights on my back under cars with flood lights and propane heaters. Hint: you need a stock of hot chocolate and a warm women waiting inside your house!

If you test the circuit for battery with the key in the On/Run position; then you only have about 3 seconds before the PCM times out. This is because the PCM needs a Cam & crank shaft signal. If it does not see these then it de-energizes the ADS relay (automatic shutdown relay). The ADS relays powers the fuel pump relay. The relays will make a clunk when energized. However this is not true when power is removed from them! They have a soft return. I place a finger on each the two relays when I want to see if power is getting to them. That way you are fooled by other neighbouring relays in there.

well what would happen if i put a jumper in the place of the relay? Would that cause any harm to any of the other electrical systems? im not sure if its that relay or not cause the car will drop to 0 rpms for like half and second and then bring it back to life on its own. I have spent all day looking for a suspicious sensor and im about to call it quits.
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1996 ZJ 4.0 L with 255k

11-09-2007, 10:20 AM #4
greasefingers
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