P0758 on Pontiac: How to Diagnose & Fix
Shift Solenoid "B" Electrical
1 Pontiac model · 1 documented issue · $250-$3,200 repair
P0758 on Pontiac by model: symptoms, diagnosis and fix
The 4T65E (and 4T65E-HD behind the supercharged L67) used in 1997-2005 Bonnevilles develops progressively harder 1-2 and 2-3 shifts as the PCM adapts to lengthening shift times, eventually setting P1811 (Maximum Adapt and Long Shift). Owners on GM Forum and the Pontiac Bonneville Club describe a slam-shift that appears after 20-30 minutes of driving, then becomes constant. Root causes identified by the community and rebuilders are broken 1-2/2-3 accumulator springs, a worn pressure control solenoid (PCS), worn Teflon sealing rings, and burned 2nd/3rd clutch material clogging shift and EPC solenoids. Pre-2003 units also have a non-hardened 4th-clutch shaft that wears its teeth. GM TSB 02-07-30-022B covers harsh shifts with multiple transmission DTCs on 2000-2004 Bonnevilles, and TSB 04-07-30-028 covers fluid leaks from a reverse-servo seal that shrinks below 20F.
Common Symptoms
- Harsh or slamming 1-2 and 2-3 upshifts, worse once warm
- Check Engine light with P1811 stored
- Delayed or flared shifts before the hard-shift stage
- Shudder at light throttle 40-50 mph (TCC)
- Eventually slipping in 2nd, 3rd or reverse
How to Fix
Early stage: replace the pressure control solenoid (side-cover job) and the 1-2/2-3 accumulator springs/pistons (Transgo or TransTec accumulator kit T84167G is the community-standard fix), clear adaptives and refill with Dexron VI. Once slipping, overheated clutch smell, or P0730/P0717 codes appear the unit needs a rebuild with the hardened 4th-clutch shaft, updated bonded valve-body plate and new sealing rings, or a remanufactured unit (about $1,900 for the unit plus labor). No recall exists; TSB repairs were only free under warranty.
Sources for this issue (5)
- 1999 Pontiac Bonneville with hard shifting transmission - GM Forumforum
- T84167G Should resolve P1811 Code - GM Forumforum
- Transmission Experiences 4T65E - Especially Failure : Pontiac Bonneville Clubforum
- P1811 code on my 4T65E transmission, what are my options? - Bob Is The Oil Guyforum
- Pontiac Bonneville Transmission Problems and Cost (TSB 02-07-30-022B, 04-07-30-028)article
P0758 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P0758 mean on a Pontiac?
P0758 stands for "Shift Solenoid "B" Electrical." This powertrain code indicates an electrical fault in the transmission's shift solenoid 'B' circuit. Shift solenoids are electrically controlled valves that route transmission fluid to engage the correct gears (solenoid B is commonly associated with the 2-3 shift). The transmission computer detected the solenoid circuit electrical value (voltage/current) outside the expected range. This can cause harsh or missed shifts, slipping, or the transmission entering limp mode, and should be addressed to avoid further transmission damage. On Pontiac it is documented across 1 model: Bonneville.
What are the most common causes of P0758?
The most common causes of P0758 are: Faulty shift solenoid B, Damaged, shorted, or open solenoid wiring/connector, Low or contaminated transmission fluid, Clogged or worn valve body passages, Internal transmission electrical (harness) fault, Faulty transmission control module (less common). The specific cause varies by vehicle.
How much does it cost to fix P0758 on a Pontiac?
Published repair estimates on Pontiac range from $250 to $3,200 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
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Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.