[Melze]

Received an email from OnStar Notifications Advanced Diagnostics:

"An issue with the Engine and Transmission System in your 2016 Cadillac ATS has been detected.
Please service your vehicle within 7 days."

My wife took the car for a 50 mile trip this morning. No symptoms, no CEL. I took it on a really hard drive when she got back. No symptoms, no CEL. I have a 160 mile trip scheduled for tomorrow. I called my dealer and spoke to the service rep who said if there are no warnings and the car is acting okay, keep driving. Obviously I'd like to get the car scanned, and my OBD reader has conveniently gone bad. Ordered a new one, but it won't be here before I have to leave tomorrow. I'll schedule a service visit ASAP, but I need to make the trip tomorrow. Has anyone gotten this kind of message, and are they accurate or just a glitch?

 

[kwroton57]

Received an email from OnStar Notifications Advanced Diagnostics:

"An issue with the Engine and Transmission System in your 2016 Cadillac ATS has been detected.
Please service your vehicle within 7 days."

My wife took the car for a 50 mile trip this morning. No symptoms, no CEL. I took it on a really hard drive when she got back. No symptoms, no CEL. I have a 160 mile trip scheduled for tomorrow. I called my dealer and spoke to the service rep who said if there are no warnings and the car is acting okay, keep driving. Obviously I'd like to get the car scanned, and my OBD reader has conveniently gone bad. Ordered a new one, but it won't be here before I have to leave tomorrow. I'll schedule a service visit ASAP, but I need to make the trip tomorrow. Has anyone gotten this kind of message, and are they accurate or just a glitch?

Same thing happened to me over a week ago. I got both an OnStar email as well as two messages in the center between the gas and speedo. No CEL. Dealer found no issues. Nothing since then and OnStar now reports everything is good. I drove it from Philadelphia to Pittsburgh and back with no issues.

 

[Melze]

Update: Since I am paranoid over my cars, I dropped by AutoZone and had the OBD codes read. P700 and P701 concerning transmission temperature. And as I left AutoZone the CEL came on, with no messages in the DIC. I called the dealer, who I did not by the car from, but is now my local dealer and spoke to the service rep who said bring it on in now, I'll have a loaner waiting for you. And they did; a spanking new XTS 3.6 with everything, and I mean everything. 98 miles on the odometer. I can tell you, aside from all they toys, bells and whistles, I can't wait to get my ATS back.. But lots of fun things to play with, including the automated parking. And I really like the mood lighting. But the engine has no guts and the transmission is soft. It's a luxobarge and I recognize that many people like luxobarges, but not me.

 

[RedCadi]

Loaners can be fun. They put me in an XT5 yesterday. First time driving an SUV. It's not a bad ride. I renewed the insurance on the cars this morning. Stepped into the garage with the new cards and screamed when I saw the loaner. I just can't do ugly.

 

[Melze]

Update: Spoke with the dealer who said a wiring harness in the transmission has to be replaced. A wiring harness in the transmission? New one on me. They'll have the harness tomorrow and I'll have the car the next day. I was driving so I didn't want to have a long discussion with the person who called. I'll have a face-to-face on Friday and look up the part number from the work order. Meanwhile I put 250 miles on the loaner today, and while all the toys are fun, I want my ATS back.

 

[Melze]

Dealer called today, said the harness is on a two week back-order but I can drive the car with no problem. I guess they wanted their expensive loaner back. Picked it up. It drive fine. Used my BlueDriver code reader to scan, came up with the same fault. I cleared the CEL because I don't want it hiding another fault. So far, after a 20 mile drive, no CEL. I'll wait. I'm sure it will come back. I'll keep checking. BTW, does anyone know what the letters ML stand for? It precedes the fault description, as in ML Transmission harness temperature detection.

 

[Melze]

Update: 3 days ago I cleared the temporary code, leaving the permanent code in memory for the future repair, and continued to drive the car. Did a few hundred miles before I had to bring the car back to the dealer for an A/C fault (see https://www.cadillacforums.com/threads/air-conditioner-fail-solved.1088765/). Picked up the car this morning and drove a 50 mile run. The CEL has not come on. Strange. I'l see how far I get before it turns on again, if it turns on at all. Harness should be in next week. It will be interesting.