P1870 on Chevrolet
GM: transmission component slipping, usually at the torque converter clutch
Severity: Inspect soon
When P1870 sets, the computer raises line pressure and stops applying the converter clutch to protect the transmission, so it keeps driving but with harsh shifts. The slip behind it can worsen, so get it inspected soon.
It gets more serious if:
- Not verified: The transmission goes into limp-home mode (stuck in one gear, little power) or will not shift. Regulations require the light in limp-home mode, but we found no source saying whether you must stop
This page covers only what differs on Chevrolet. For what P1870 means, the ranked causes and the test order, see the P1870 guide.
What's different on Chevrolet
ChevroletYour car
2000–2001 · Silverado 1500
Supported by vehicle dataGM 3047 covers harsh converter clutch apply and/or P1870 on the 4L80E in Silverado, Suburban and Express. The bulletin is on NHTSA, but whether it is still current is not verified, so it is labelled vehicle data rather than confirmed.
1996–2000
Supported by vehicle dataGM 01-07-30-023B covers a harsh 1-2 upshift with P1870 on Chevrolet and GMC trucks, Camaro and Corvette. The bulletin is on NHTSA, but whether it is still current is not verified, so it is labelled vehicle data rather than confirmed.
1997 · Camaro
Supported by vehicle dataGM 97-12-01-777-17A covers converter clutch slip and/or P1870 at 45–55 mph. The bulletin is on NHTSA, but whether it is still current is not verified, so it is labelled vehicle data rather than confirmed.
020730001AStatus unverified
DTC P1870, transmission component slipping
2000–2002 · issued · NHTSA 628845
Diagnostic information on P1870 for 2000–2002 passenger cars and light trucks, later updated to include 2004 models. GMC, Buick and Cadillac are also listed. Only the NHTSA flat-file summary was reviewed, not the bulletin itself.
We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.
010730023BStatus unverified
Harsh 1-2 upshift with the MIL and P1870
1996–2000camaro, corvette · issued · NHTSA 634815
Some customers may report a harsh 1-2 upshift with the check engine light on and P1870 set. Chevrolet and GMC trucks are also listed. Only the NHTSA flat-file summary was reviewed, not the bulletin itself.
We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.
3047Status unverified
Harsh TCC apply and/or P1870, 4L80E
2000–2001express, silverado-1500, suburban · issued · NHTSA 10009392
Covers harsh converter clutch apply and/or P1870 on the 4L80E. The GMC Savana, Sierra 1500 and Yukon are also listed. Only the NHTSA flat-file summary was reviewed, not the bulletin itself.
We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.
PIP5340AStatus unverified
Harsh 1-2 upshift and MIL after transmission or converter replacement
1998–2006astro, blazer, express, s10, silverado-1500 · issued · NHTSA 10096073
After a transmission or torque converter replacement the vehicle may have a harsh 1-2 upshift and the check engine light on. GMC models are also listed. Only the NHTSA flat-file summary was reviewed, not the bulletin itself.
We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.
97120177717AStatus unverified
TCC slip and/or P1870 at 45–55 mph
1997camaro · issued · NHTSA 54010
Covers slip and/or P1870 at 45–55 mph when the converter clutch applies. Only the NHTSA flat-file summary was reviewed, not the bulletin itself.
We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.
Sources and review
- GM 3047: harsh TCC apply and/or DTC P1870, 4L80E
- GM 01-07-30-023B: harsh 1-2 upshift, MIL and DTC P1870
- GM 97120177717A: 1997 Camaro TCC slip and/or DTC P1870 at 45–55 mph
- Deciphering GM Transmission DTC P1870
- Beyond 1870: GM Converter Codes P0741, P0742 and 1887
- Cal. Code Regs. Tit. 13, § 1968.2 — Malfunction and Diagnostic System Requirements (OBD II)
- Last reviewed
- Written by
- Saurabh K.
- Editorial review
- Pending
- Technician review
- Technician review pending
This page explains what a code usually means; it is not a substitute for a professional inspection. How we source and review · Report an error