P0758: How to Diagnose & Fix — Shift Solenoid "B" Electrical

Mk4 Jettas ordered with the 01M/AG4 four-speed automatic (1999-2005, behind the 2.0 ABA/AVH, 1.9 TDI ALH and VR6) commonly suffer valve body and internal wiring-harness failure. The solenoid pack's internal harness (01M325283A) and the shift solenoids themselves degrade, producing hard or delayed shifts, slipping on the 2-3 change, flare, and eventually a transmission that drops into limp mode and holds a single gear. Shift-solenoid A and B circuit faults (P0753 / P0758) are the fingerprint. The 01M was also fitted with no factory-scheduled fluid service, and lifetime-fill neglect accelerates the failure. This is distinct from the later DSG mechatronic problem and applies only to the conventional torque-converter automatic.

The first-generation Passport's 4-speed automatic is widely documented for torque-converter clutch shudder, slipping, harsh shifts, and eventual hard-part failure, especially loss of 2nd gear. Honda issued service information tied to Isuzu-sourced driveline components, and owner complaints frequently describe the vehicle revving without acceleration or dropping into limp behavior after warm-up. Once clutch material contaminates the fluid, the problem often progresses quickly from intermittent shudder to a full rebuild or replacement.

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.

P0700 is not a specific fault by itself — it is an umbrella/MIL-request code the ECM stores whenever the transmission control module (TCM) detects an internal transmission problem and asks the ECM to turn on the check-engine light. On the Silverado 1500 it almost always appears alongside more specific companion codes, and the underlying failure follows two dominant, well-documented patterns depending on the transmission. On trucks with the 6L80 six-speed automatic (2007-onward 5.3L and 6.2L V8 models), the internal TEHCM (Transmission Electro-Hydraulic Control Module — GM's combined valve body, solenoids, pressure switches, and TCM in a single pan-mounted unit) develops internal circuit-board/solenoid faults from heat and fluid degradation, throwing P0700 together with codes like P0796, P0777, P0842, or P0973 and dropping the truck into limp mode. On older/base trucks with the 4L60E four-speed (4.3L/4.8L), the same P0700 is typically triggered by a failed shift solenoid (P0753/P0758) or a faulty internal mode switch. Because P0700 is a stored 'passenger' code, a scan tool that can talk to the TCM (not just a basic reader) is required to pull the specific sub-code that identifies the actual failed component.

The 4-speed automatics on 1990s D16 Civics develop slipping and harsh or stuck shifting. Frequent causes are a failing shift-control solenoid and, distinctively, the distributor O-ring leaking oil onto the transmission solenoid connectors. Torque-converter breakdown that burns the fluid is the more severe failure mode and worsened into the following (2001+) generation.