Jake Brake Issue on '06 5.9

[TRFD]

I have '06 with the factory Jake Brake. It will operate after starting the engine when idling but will not operate when driving.

I checked the vacuum pump (good suction) and ran through the electrical trouble shooting steps from the installation manual up to the ECM tests. Works while idling but not driving.

Anyone else seen this issue?

 

[mwilson]

Manual or Auto transmission?

 

[TRFD]

Automatic transmission

 

[p-Bar]

Possibly not getting the lockup signal from the trans? ECM issue?

 

[TRFD]

Possibly not getting the lockup signal from the trans? ECM issue?

Where does the lock up signal from transmission come from? Easily found plug/wire?

 

[p-Bar]

It's too integrated to try to figure it out . Sounds like a dealer trip. I have a stand alone BD brake much easier to troubleshoot if their is an issue

 

[bigceltic]

I have '06 with the factory Jake Brake. It will operate after starting the engine when idling but will not operate when driving.

I checked the vacuum pump (good suction) and ran through the electrical trouble shooting steps from the installation manual up to the ECM tests. Works while idling but not driving.

Anyone else seen this issue?

Have you done the troubleshooting steps from the manual? http://www.jacobsvehiclesystems.com/files/support/docs-pdfs/32414 E2_Screen.pdf I had a prob and isolated it to the electrical system - a wire had pulled out of the wire harness.

 

[mfurrh55]

I have a stand alone BD brake much easier to troubleshoot if their is an issue[/QUOTE]
Same here, i by passed the ECM

 

[TRFD]

***Update***

I made the dealer trip, the PCM is bad, truck throwing 0477 code.

Replace the PCM- $2000 from Dodge or $895 from other retailer.

The mechanic suggested by passing the PCM and go to brake switch. Any help on the by pass??

 

[p-Bar]

Fault code 0477 (Low voltage - ECM pin B42). With
the exhaust brake switch in the off position, no voltage
is detected on Pin B42 (12 Volts is expected). Inspect
Light Green wire on the brake harness.

Did you check the green wire for power? This is from the Jacobs troubleshooting manual

 

[bigceltic]

Fault code 0477 (Low voltage - ECM pin B42). With
the exhaust brake switch in the off position, no voltage
is detected on Pin B42 (12 Volts is expected). Inspect
Light Green wire on the brake harness.

Did you check the green wire for power? This is from the Jacobs troubleshooting manual

This was my issue, green wire had pulled out a bit and had to be reinserted and secured. Once done the brake worked perfectly again.

 

[sag2]

Cummins controllers hardly ever go bad. I agree it is most likely a wiring/connector concern.

 

[TRFD]

Fault code 0477 (Low voltage - ECM pin B42). With
the exhaust brake switch in the off position, no voltage
is detected on Pin B42 (12 Volts is expected). Inspect
Light Green wire on the brake harness.

Did you check the green wire for power? This is from the Jacobs troubleshooting manual

Dealer tech spent an hour testing using the Jacobs install/service manual. He came up with the bad PCM diagnosis.

He suggested the bypass, he said tie the green wire to the brake switch.

Is the bypass a good alternative or is getting a replacement PCM a better solution?

 

[p-Bar]

Doesn't make sense That he said the PCM is bad , the brake only uses signal and power from the ECM ? The schematic of the Brake sucks as I can't trace the wires so I can't tell you how to "hotwire " it. Makes no sense what the tech is saying. Need to check the voltage on the light green wire

 

[TRFD]

I went through the trouble shooting list from Jacobs. Lt Green wire is intact but has no voltage. Could the PCM actually be bad?

 

[p-Bar]

Did you read bigceltic's response? The wire could have gotten pulled. Push it back in to the connector. ECU is on the side of the engine. Trace the wire to it

 

[bigceltic]

Did you read bigceltic's response? The wire could have gotten pulled. Push it back in to the connector. ECU is on the side of the engine. Trace the wire to it

When my brake stopped working, I did all the troubleshooting steps and ended up with the "green wire" prob. I visually inspected it but it looked like it was still inserted in the ECU. I took to the installing dealer and told them the wire needed to be re-inserted and secured, and they called me back a couple of hours later and said "the wire needed to be reinserted and secured" ;-) - I guess they did not trust my diagnostic skilz - and they did so and the brake has worked perfectly since.

 

[TRFD]

Automatic Transmission

 

[TRFD]

Is that special tool Dodge only would a repair shop have one?

 

[TRFD]

The issued turned out to be a bad wire to the switch on the shifter stalk.

Access to the internal parts of the original switch is not easy without damaging the box.

Sadly the push pull switch which was OE is no longer available. Dodge has a switch which goes in the dash above the cigarette lighter next to the fan switch.