key trick to read the ECM.

[GSP7]

What year trucks can this be done?

 

My '99 does not do it as I remember. Been along time

 

What exactly do you do with the key to read ECM codes and where do you read the codes at?...... (where the odometer mileage numbers are.? )

 

Nother quesition after I find out the above

 

 

.

[dripley]

Key on key off key on key off key on then look at the odometer. Not sure what yours will read. The ECM at best, I am not sure on the 99.

[Mopar1973Man]

1998.5 and 1999 do not work.

 

2000 and 2001 may or may not read both typically just the PCM.

 

2002 will display both PCM and ECM codes. 

[dripley]

1 hour ago, Mopar1973Man said:

1998.5 and 1999 do not work.

 

2000 and 2001 may or may not read both typically just the PCM.

 

2002 will display both PCM and ECM codes. 

Sounds like I have it backwards. I thought it read the ECM and not the PCM. 

[GSP7]

Huh ?

 

 

.

[Mopar1973Man]

8 hours ago, dripley said:

Sounds like I have it backwards. I thought it read the ECM and not the PCM. 

 

Yeah you do. The old post over on CF was of the P1693 code was because the 2000 and 2001 would report the P1693 code and nothing more for a failed VP44. This because Cummins didn't have the code added in the ECM for the key trick so Dodge PCM typically always had it but the 98.5 and 99 didn't get the key trick. 

 

The order it read codes is ALWAYS PCM first then ECM (companion module). Even on the 2002 it reports P_PCU and  P_ECU in that order. 

 

 

Just for information value. Disconnecting the batteries does not clear any codes ore reset any computers. 

 

Edited March 4, 2018 by Mopar1973Man

[GSP7]

Is the key trick programed into something?

 

I have a new re-manufactured and updated software ECM.

 

Could the Key trick possibly be activated with a new ECM or is the trick part of the odometer's program or ....?

 

Edited March 4, 2018 by GSP7

[Mopar1973Man]

12 hours ago, GSP7 said:

Is the key trick programed into something?

 

I'm pretty sure it programmed into both the PCM and ECM. Being the 2000 and 2001 both are known to report only PCM error codes where the ECM was missing the code to report it errors.

 

12 hours ago, GSP7 said:

Could the Key trick possibly be activated with a new ECM or is the trick part of the odometer's program or ....?

You have to remember the master computer is the PCM and the ECM is just a companion module.