Cat D5G HYDROSTATIC ECM light Illuminated, NO START

[Pigpen]

Hello,

2005, Cat D5G (RKG01078)

I have been having delayed start issues, i.e., move the key to start and nothing happens for several seconds. Sometimes, more recently, i have to return the key switch to OFF, then try again. Only once have I seen the red exclamation light illuminate during the start process and that was corrected by cycling the parking brake switch.
But today it's on for good.

I have a digital manual but I see no RENR 55XX pubs, only 7XXX pubs. My Operation and MX manual says to refer the Hydrostatic ECM alert to RENR 5539 and RENR 5544. The closest I found was RENR 7313 and RENR 7314.

I suspected the ignition switch so I replaced it, and when that didn't help, I replaced the starter relay. But now I have the red ECM light that stays on, while in neutral, with the parking brake set. One year ago the Parking Brake Solenoid was replaced but I didn't change out the Override Solenoid.

I have not pulled any diagnostic codes yet. I do get 12.21 Volts to the starter.

Does anyone have RENR 5539 or 5544?

Could the Override Solenoid be an issue?

Would replacing the ignition switch require a reprogramming of the ECM?

I checked grounds and I replaced the strap on the port side of the engine, the starboard side checked out fine.

I did this work with the master batt kill switch ON.



Thank you in advance!
Steven

 

[Nige]

I have not pulled any diagnostic codes yet.

Do that as a first step. It will save you a lot of time and money firing the Parts Cannon.

As an aside you need to see a voltage of at least 13.5v with the engine running. These machines do not tolerate low voltage.

See this thread. It has a copy of RENR7313 in it.

https://www.heavyequipmentforums.com/threads/d4g-lgp-parking-parking-brake-issues.120272/

 

[stephenrobinson98741]

Hello,

2005, Cat D5G (RKG01078)

I have been having delayed start issues, i.e., move the key to start and nothing happens for several seconds. Sometimes, more recently, i have to return the key switch to OFF, then try again. Only once have I seen the red exclamation light illuminate during the start process and that was corrected by cycling the parking brake switch.
But today it's on for good.

I have a digital manual but I see no RENR 55XX pubs, only 7XXX pubs. My Operation and MX manual says to refer the Hydrostatic ECM alert to RENR 5539 and RENR 5544. The closest I found was RENR 7313 and RENR 7314.

I suspected the ignition switch so I replaced it, and when that didn't help, I replaced the starter relay. But now I have the red ECM light that stays on, while in neutral, with the parking brake set. One year ago the Parking Brake Solenoid was replaced but I didn't change out the Override Solenoid.

I have not pulled any diagnostic codes yet. I do get 12.21 Volts to the starter.

Does anyone have RENR 5539 or 5544?

Could the Override Solenoid be an issue?

Would replacing the ignition switch require a reprogramming of the ECM?

I checked grounds and I replaced the strap on the port side of the engine, the starboard side checked out fine.

I did this work with the master batt kill switch ON.



Thank you in advance!
Steven

I wouldn't suspect the override solenoid just yet. The delayed crank issue combined with the Hydrostatic ECM warning light makes me think you should pull the diagnostic codes before throwing any more parts at it. The ECM is likely seeing an input it doesn't like (park brake switch, neutral signal, start circuit, etc.) and preventing or delaying cranking.

Replacing the ignition switch does not require ECM reprogramming, so you can rule that out.

Also, 12.21V at the starter seems a little low if that's measured during a crank request. I'd verify battery condition, voltage drop across the cables, and all ECM power/ground connections.

As for the manuals, the RENR numbers were superseded on a lot of older Cat publications. If you're missing service literature, this Caterpillar manual collection might help track down the correct documents for your machine: https://manualskart.com/collections/caterpillar-all-equipments-pdf-manuals

First step though: pull the active and logged codes. That'll point you in the right direction much faster than guessing at components.

 

[CM1995]

As an aside you need to see a voltage of at least 13.5v with the engine running. These machines do not tolerate low voltage.

Agree.

For something simple PP I would look at batteries and alternator first. The G series dozers like to be in the 14.4 range for everything to be warm and fuzzie.

If that doesn't work then follow whatever Nige tells you to do.

 

[Nige]

Yeah, certainly make sure that the system voltage is good before proceeding further. While you are in there check belt condition and tension.

 

[Pigpen]

I got it sorted out, it was the starter relay that was bad. But I guess the machine didn’t like the generic ignition switch so I put the old one back in so now it starts fine with no ECM issue.

The 12.21 Volts was my battery strength with the key ON, not the voltage while cranking. Funny you mentioned the alternator belt, I had just tightened it up while I was checking everything. Thanks everyone.