What is the ASD relay on a Jeep Cherokee?
Circuit A21 powers circuit F99 through PDC fuse 18. Circuit F99 feeds the coil side of the Automatic Shut Down (ASD) relay. The Power train Control Module (PCM) provides ground for the relay on circuit K900.
Where is the ground on a jeep starter?
If you see battery voltage, check for ground on pin 85 in the relay socket. The PCM provides ground to the starter relay control coil AFTER it determines the anti-theft system has passed the authentication test.
What does a problem with the ASD relay mean?
Another symptom of a possible problem with the (ASD) relay is an illuminated Check Engine Light. So, If the computer detects that a problem with the (ASD) relay or circuit has occurred; it will illuminate the Check Engine Light to alert the driver of a problem.
Where are the ground points on a Jeep Cherokee?
Note that some of these are ‘add-on’ ground points! The factory wimped out and only used the harness and a braided ground strap located on the rear, driver’s side of the head that then attaches to the firewall. If someone removes this ground strap (or it goes bad) then you will end up with all kinds of bizarre electrical and engine issues!
What are the fuses on a Jeep Grand Cherokee ASD relay?
NOTE: The above auto shut down (ASD) relay wiring diagram applies only to 1993, 1994, 1995 4.0L Jeep Grand Cherokee. The auto shut down (ASD) relay gets power from fuse #6 (15 Amp) and fuse #15 (30 Amp) of the Power Distribution Center (PDC).
How does auto shut down ( ASD ) relay work?
The auto shut down (ASD) relay gets power from fuse #6 (15 Amp) and fuse #15 (30 Amp) of the Power Distribution Center (PDC). The PCM activates the ASD relay and the fuel pump relay at the exact same time and thru’ the same circuit (PNK wire). The PCM activates the ASD relay when the ignition switch is in…
What are the symptoms of a bad ASD relay?
One of the most common symptoms of a bad (ASD) relay is an engine that will start. But, Stalls almost immediately, or at random times. The (ASD) relay supplies power to the vehicle’s ignition coils and fuel injectors.
How to connect jumper wire to relay terminal 85?
Connect one end of a jumper wire (16 gauge or smaller) to relay terminal 85. Then, Connect the other end of the jumper wire to the ground side of a 12-volt power source. Connect one end of another jumper wire (16 gauge or smaller) to the power side of the 12-volt power source.
Why does my Jeep Cherokee crank but not start?
Re: Cranks but will not start, no PCM function. You still don’t have spark or injector pulse; this should be looked into first. It still could be a bad crank sensor. The crank sensor sends the pulse to the PCM and then it sends the signals to the proper areas like spark, fuel relay, and injector pulse.
What is the automatic shut down relay on a jeep?
ASD relay “Automatic Shut Down relay” used on all EFI jeeps. 1990 to present. What is it? It is a safety device, that exists by LAW and for good reasons. It CAN prevent FUEL fires (the Classic Crash and burn reason) and engine hyrdolocking.
Where is the ignition switch located on a Jeep Cherokee?
When the ignition switch is in either the START or RUN position, it connects circuit A1 from fuse 8 in the Power Distribution Center (PDC) to circuit A21. Circuit A21 powers circuit F99 through PDC fuse 18.
What causes a jeep ASD relay to stop working?
Can be 50 causes, but in macro form is, bad engine bad spark plugs and wires, bad fueling, which can be flooding or lost fuel pressure (stavation) Stalls for bad engine are lost compression hot. Some engine can do that, even stuck open head valves now or only HOT. (and many more issues inside the actual engine)
ASD relay “Automatic Shut Down relay” used on all EFI jeeps. 1990 to present. What is it? It is a safety device, that exists by LAW and for good reasons. It CAN prevent FUEL fires (the Classic Crash and burn reason) and engine hyrdolocking.
What does the Check Engine light on an ASD relay mean?
Another symptom of a possible problem with the (ASD) relay is an illuminated Check Engine Light. So, If the computer detects that a problem with the (ASD) relay or circuit has occurred; it will illuminate the Check Engine Light to alert the driver of a problem. The Check Engine Light can also be activated for a wide variety of other reasons.
How does the ASD work on a jeep?
The system and how it works. The ASD has engine startup logic that is unique to JEEPs. You must crank with in seconds or the key on, is ignored by many jeeps. You crank the engine, and the above list of logic checks, must not fail, during the start event or it cuts the ASD.