Many years ago, GM would take its top 10 ranked performers in service and host a multi-day conference with corporation executives to discuss issues with service, training, engineering, manufacturing, parts, dealers, and vehicle technology. It was always a great trip for those of us who attended, as we could bring our spouses, and GM would do their best to make the trip memorable for the spouses as a thank you for all the time and dedication the employees had shown the corporation and the dealer body. For those of us who were meeting each day with the executives, it was always enlightening as we learned what products were on the drawing board for the future as well as you had an opportunity to discuss issues that each of us had with overall service as well as specific GM service operations.
One such meeting with the VP of GM service focused on the effectiveness of the GM dealer technician to “fix the car right the first time.” The executives could not understand why dealer technicians were struggling because it should not be happening, according to the engineers. We had to be careful in these meetings as we did not want to call somebody’s baby “ugly” as all hell could break loose.
The VP at the time was adamant that he wanted to know the truth, so we told him that the main problem was related to how inaccurate and vague the service manuals were across all GM vehicle brands and body styles. The VP demanded that each of us provide a percentage value related to the accuracy of the information. He went around the room to each of us to provide our assessment. What we told him left him with his mouth wide open and visibly upset. We said we estimated that the repair manual accuracy was about 60%. After returning from a break, the VP informed us that the executive committee had a plan to address our issues, and its implementation would start at the beginning of the month.
He was ordering all GM service operations to strictly limit or shut down their service support until all of the current manuals could be proofread and all of the issues addressed by all of us that had anything to do with service. This meant that training center access, service engineering support, technical assistance support as well as anything else to do with service were on hold for the next month or until the issues were addressed. While this was a scheduling nightmare for management as they tried to keep service running on a shoestring staff, it did wonders to address the issues with the manuals. It cost the corporation a ton of money to “back up the bus”, but it paid huge dividends in the years that followed.
In my assessment, we are back in the same boat again with the available service information. I am constantly finding wiring schematics, DTC flow charts as well as the theory of operation sections that are woefully lacking when it comes to repairing a vehicle. I hear it almost on a daily basis from dealers and independent technicians about how they are struggling to repair just about every brand of vehicle in their stalls and how the manual led them astray.
Last week I received a call from a large GM store that had a 2023 Buick Encore with a 9T45 and a no reverse condition. The customer had stated that the car was working great until she tried to back out of a parking spot, and reverse would not engage. The technician was a seasoned veteran with a lot on the ball. I told him I thought the transmission had an issue with the #9 check ball. If not, he should look for issues with the solenoids 1, 5, 6, and 9 or their clutch regulator valves, which could also cause issues with reverse, but that some of the solenoids/ valves would also cause other issues. He could also have an issue with the 5-7-R clutch, but he insisted that it only affected reverse, so I told him to start with the check ball.
The next morning, he called and told me that he could not find the #9 check ball, so I went to look at the manual, and sure enough, the hydraulic schematic showed the #9 ball, but the check ball locations pictures did not. The #9 check ball is a two-way ball that controls the operation of the 5-7-R clutch. I stopped at the dealer on my way to the airport, and sure enough, the technician was correct. The manual shows check balls numbered 1,2,3,4,5,6 for the control valve body case side, # 1, 2 control valve body solenoid side, and # 1,2,3,4,5 on the automatic transmission case side. So, according to the check ball location charts, we have 13 check balls, but none of them are the number 9 shown in the hydraulic schematics.
As you can see in Figure 1, the #9 ball (#3 in Figures 2a-2b) is stuck in the valve body, which is what the ultimate cause of concern was in this scenario. This meant a valve body and spacer plate needed to be installed, which the technician did that afternoon with reverse again operating as it should. So, what is the moral of this story? One expects the manual as well as the scan tool to contain accurate information, but in the last several years, it seems both have large holes that can lead you astray if you are not careful. This issue affects many of the product brands on the market as they get their information directly from the OEM manufacturer. So if it is wrong coming from the manufacturer, the tool data parameters will likely be incorrect as well, which may be why you are struggling to fix the vehicle in your stall.
So, what is the solution? On the information side, one can only hope that someone caught the issue and had it corrected before a car arrives in your shop. If you happen to be the first one to run across the issue with the repair information, make sure you inform the company that provides your service manual information the specifics so the issue can be corrected before it makes someone else challenge their sanity. On the scan tool side, I have always recommended that your shop has access to more than one brand of scan tool so you can validate the information you are seeing if you have any doubts that it is correct.
Until next time, remember, “In the middle of difficulty lies opportunity.”
