Question...
Hello Vince,
I was driving my 1990 Dodge Caravan when it felt as if the gas pedal was jerked out from under my foot. I tried to give it gas, to no avail. It has not started since. It turns over, but will not start. My neighbor changed the fuel filter, to no avail. At first he thought it was not getting gas, now he thinks it also has no spark. I would greatly appreciate any advice you can give. I have very limited income and cannot afford to replace many items to find what is wrong.
Thank you so much!
Diana Evans
Answer...
Chrysler uses what's known as an Auto Shut Down relay. The ASD relay supplies battery voltage (12+ volts) to the fuel injectors and ignition coil(s). With certain emissions packages it also supplies 12 volts to the oxygen sensor heating elements. The ground circuit for the coil within the ASD relay is controlled by the Powertrain Control Module (PCM). The PCM operates the ASD relay by switching its ground circuit ON and OFF.
The ASD relay will be shutdown, meaning the 12-volt power supply to the ASD relay will be de-activated by the PCM if:
- The ignition key is left in the ON position. This is if the engine has not been running for approximately 1.8 seconds.
- There is a crankshaft position sensor signal to the PCM that is lower than pre-determined values.
So if you do not have fuel or spark, it is probably due to a bad ASD relay. On your vehicle there is a relay bracket next to the battery. Looking across the top of the battery at the relay bracket, the ASD relay would be the left most relay on the bracket.
Terminal 30 should have battery voltage . If not check the fuses and fusible links.
