Dodge Repair Questions? Ask a Mechanic for Answers ASAP
Hello and welcome!
When this occurs try cycling the key off and then back on. Does the check engine light immediately turn on with the key?
This will give a indication if the pcm is communicating.
Do you have access to a scan tool?
No bus message means no communication with the PCM. After a few minutes the Check engine light will turn on but there will still be no communication with the pcm.
I have seen a lot of PCM failures on your year range vehicle.
Do you have experience using a digital mulit meter or have a test light?
I can help you test the power and ground circuits to the pcm, before you make the purchase.
What engine is in your vehicle?
This is so i can look up the correct wiring diagram.
You will need to buy a test light. This is the easiest way to test power and ground to the pcm.
Perform this test while the engine is not running and the no buss message is displayed.
Test Key on engine off.
There is 3 connectors for the pcm, remove the black connector, i think it is on one on the right side of the pcm.
Test for power at pins 2 and 22. With the test light, connect the clip to the negative battery cable touch the probe to pins 2 and 22.
The ground pins are 31, and 32. With the test light connect the clip to the positive battery cable and test for ground at pics 31, and 32.
If the test light turns on at all 4 pins in the ecm black connector the pcm will need to be replaced.
Test for battery voltage on pins 2 and 22. Put the meter on direct current dc, black lead on the negitave battery cable. Red lead on pins 2 and 22 should get battery voltage reading.
To test the ground side Key off engine off. Set the meter on OHMS, black lead on negative batty cable. Red lead on pins 31 and 32 should get less then 5 OHMS
The best test is to use the test lamp, this puts a load on the circuit like the pcm would.
I only strive for excellent service, if you have any other questions please let me know.