I need to find out what exactly "no bus" stands for on my 1999 dodge durango. i know what the problem is, i know how to fix it, i just would like to know what "no bus" stands for..? thanks
"No Bus" means the data cable going to the (PCM) computer is unplugged, or the PCM has failed and not able to read the information it is being given.
Sometimes just jiggling the PCM causes the ODO "NO BUS" to come on.
Sometimes a bad crank or cam sensor can cause this as well.
Here is the OFFICIAL checklist for the "NO BUS" condition....
Vehicle: 1998 - 1999 Dodge Durango 3.9L
2000 - 2001 Dodge Durango 4.7L
1998 - 2000 Dodge Durango 5.2L
1998 - 2001 Dodge Durango 5.9L
Symptom: Engine will not start. Gauges are inoperative. No BUS message displayed on odometer.
System: Body/Chassis Electrical, Emissions/PCM/Fuel, Engine Electrical
Codes: N/A
Problem 1 of 6: The 5v power supply from the Powertrain Control Module (PCM) is shorted due to a shorted Crankshaft Position (CKP) Sensor.
Test & Fix: If the 5v power supply circuit is shorted to ground, the CCD bus is unable to transmit messages and the Powertrain Control Module (PCM) appears to be "dead". The PCM is not damaged when the 5v power supply gets shorted to ground, but does need to be reset by turning the key off for 10 second after the short is removed. Using a DVOM or labscope, measure the voltage on the 5v reference wire at the Throttle Position Sensor (TPS) or Manifold Absolute Pressure (MAP) sensor. If 5v is not present, unplug the Crankshaft Position (CKP) Sensor. Turn the key off for 10 seconds. Turn the key on and measure the voltage on the 5v power supply circuit. If the voltage is now 5v, replace the CKP sensor.
Problem 2 of 6: The 5v power supply from the Powertrain Control Module (PCM) is shorted due to a shorted Camshaft Position (CMP) Sensor.
Test & Fix: If the 5v power supply circuit is shorted to ground, the CCD bus is unable to transmit messages and the Powertrain Control Module (PCM) appears to be "dead". The PCM is not damaged when the 5v power supply gets shorted to ground, but does need to be reset by turning the key off for 10 second after the short is removed. Using a DVOM or labscope, measure the voltage on the 5v reference wire at the Throttle Position Sensor (TPS) or Manifold Absolute Pressure (MAP) Sensor. If 5v is not present, unplug the Camshaft Position (CMP) Sensor. Turn the key off for 10 seconds. Turn the key on and measure the voltage on the 5v power supply circuit. If the voltage is now 5v, replace the CMP sensor.
Problem 3 of 6: The 5v power supply from the Powertrain Control Module (PCM) is shorted due to a shorted Manifold Absolute Pressure (MAP) Sensor.
Test & Fix: If the 5v power supply circuit is shorted to ground, the CCD bus is unable to transmit messages and the Powertrain Control Module (PCM) appears to be "dead". The PCM is not damaged when the 5v power supply gets shorted to ground, but does need to be reset by turning the key off for 10 second after the short is removed. Using a DVOM or labscope, measure the voltage on the 5v reference wire (5v power supply) at the Throttle Position Sensor (TPS) or Manifold Absolute Pressure (MAP) Sensor. If 5v is not present, unplug the MAP sensor. Turn the key off for 10 seconds. Turn the key on and measure the voltage on the 5v power supply circuit. If the voltage is now 5v, replace the MAP sensor.
Problem 4 of 6: The 5v power supply from the Powertrain Control Module (PCM) is shorted due to a shorted Throttle Position Sensor (TPS).
Test & Fix: If the 5v power supply circuit is shorted to ground, the CCD bus is unable to transmit messages and the Powertrain Control Module (PCM) appears to be "dead". The PCM is not damaged when the 5v power supply gets shorted to ground, but does need to be reset by turning the key off for 10 second after the short is removed. Using a DVOM or labscope, measure the voltage on the 5v reference wire (5 volt power supply) at the Throttle Position Sensor (TPS) or Manifold Absolute Pressure (MAP) Sensor. If 5v is not present, unplug the TPS. Turn the key off for 10 seconds. Turn the key on and measure the voltage on the 5v power supply circuit. If the voltage is now 5v, replace the TPS.
Problem 5 of 6: The 5v power supply from the Powertrain Control Module (PCM) is shorted due to a shorted wire.
Test & Fix: If the 5v power supply circuit is shorted to ground, the CCD bus is unable to transmit messages and the Powertrain Control Module (PCM) appears to be "dead". The PCM is not damaged when the 5v power supply gets shorted to ground, but does need to be reset by turning the key off for 10 second after the short is removed. Using a DVOM or labscope, measure the voltage on the 5v reference wire at the throttle position sensor (TPS) or manifold absolute pressure (MAP) sensor. If 5v is not present, unplug all sensors that are connected to the 5v power supply and disconnect the PCM. Check if either 5v power supply circuit is shorted to ground using a DVOM. If the circuit is found to be shorted to ground, repair the wire and the cause of the short.
Problem 6 of 6: The 5v power supply from the Powertrain Control Module (PCM) is shorted due to a shorted Governor Pressure Sensor.
Test & Fix: If the 5v power supply circuit is shorted to ground, the CCD bus is unable to transmit messages and the Powertrain Control Module (PCM) appears to be "dead". The PCM is not damaged when the 5v power supply gets shorted to ground, but does need to be reset by turning the key off for 10 second after the short is removed. Using a DVOM or labscope, measure the voltage on the 5v reference wire at the Throttle Position Sensor (TPS) or Manifold Absolute Pressure (MAP) Sensor. If 5v is not present, unplug the large round connector on the driver's side of the transmission. Turn the key off for 10 seconds. Turn the key on and measure the voltage on the 5v power supply circuit. If the voltage is now 5v, remove the transmission pan and check for shorted wiring inside the transmission. If the wiring is OK, replace the Governor Pressure Sensor.
Many times the PCM simply overheats - and changing it will stop the problem.
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finally here is a person who knows what he's talking about ,thank you for your contribution to this dodge durango no bus on dash problem .i have same problem and will start at top of list to figure out what is wrong .I have read outher peoples comments on how to fix and let me say there are a lot of people out there with too much time and too many wrong answers ..You however have done your homework or had same problem or possibly work for dodge ,either or i thank you for your input and to those others should not talk because they nothing better to do .thank you [email protected]
doesnt the PCM need to be placed on a computer
Do you have to place new PCM on computer before installing
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99 dodge durango. will turn over but not sparking and gauges dont work. have checked map sensor (good), throttle position sensor (good), crankshaft sensor (good), and put another PCM on. still doing the same thing?
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