P700 code and bad diff?

[Zach O'Neill]

My 04 TJ went into the shop today to have the transmission looked at, I just don’t have the time to do it myself. It’s for the 42RLE and is throwing a p700 code. The mechanic got back to me and said the differential was shot and would get back to me with a price. Is a damaged diff something that could throw that code ? The jeep runs and drives despite being in limp mode and there’s no/has been no sound of grinding gears. It’s a garage I’ve used before and always had good results from but just unsure if this sounds right. Am I being scammed ? Or could this be a completely separate issue to the p700?

 

[Chris]

My 04 TJ went into the shop today to have the transmission looked at, I just don’t have the time to do it myself. It’s for the 42RLE and is throwing a p700 code. The mechanic got back to me and said the differential was shot and would get back to me with a price. Is a damaged diff something that could throw that code ? The jeep runs and drives despite being in limp mode and there’s no/has been no sound of grinding gears. It’s a garage I’ve used before and always had good results from but just unsure if this sounds right. Am I being scammed ? Or could this be a completely separate issue to the p700?

The P700 code is essentially a generic code indicating that there’s a problem with the transmission control system, but it doesn’t point to a specific issue. Usually, it appears in conjunction with other transmission-related codes.

A bad diff is highly unlikely to cause a P700 code. It's possible that the mechanic is seeing issues in the diff that might be impacting the overall performance, but it wouldn't be the root cause of a transmission error code.

Given that your Jeep still runs and drives, even in limp mode, it might be worth asking them for more detailed diagnostics on both the transmission and the differential. Make sure to get a second opinion if you're feeling uncertain.