Roewe Plug-in Hybrid Electric Drive Transmission EDU Disassembly and Service Guide

Fault Background

The Roewe plug-in hybrid (1012 manual) electric drive transmission (EDU) integrates the TM motor + ISG motor + C1/C2 dual clutch, making it one of the most precise assemblies in the vehicle. Three maintenance disciplines: After replacing the EDU, four self-learning procedures must be completed in order (TM motor angle → ISG motor angle → synchronizer position → clutch engagement point pressure) and the HCU's completed self-learning count must be reset; The assembly must pass insulation and withstand voltage testing before normal use (1000V range, hold for 10 seconds, ≥5MΩ); Apply Loctite 5910 form-in-place gasket to the high-voltage wiring harness mating surface (bead width ≥3mm, bead height ≤3mm, bead located inside the bolt holes). All torque specifications are defined: engine mounting 8 bolts 75~90N·m, mount 4 bolts 63~77N·m + 85~95° angle method, cover plate 40~50N·m, water hose fitting 9~11N·m, C1 flywheel plate 6 studs 27~33N·m. This article is organized as a disassembly and service guide.

Assembly Disassembly (10 Steps)

Disassembly: ① Disconnect the battery negative terminal; ② Remove the powertrain assembly; ③ Remove the 2 bolts securing the ISG cooling water hose fitting to the EDU; ④ Remove the 2 bolts of the TM cooling water hose fitting; ⑤ Remove the 2 studs securing the upper part of the EDU to the engine; ⑥ Support the EDU assembly with a hydraulic lift device; ⑦ Remove the 2 bolts securing the cover plate to the engine; ⑧ Remove the 1 bolt securing the cover plate to the engine at the rear; ⑨ Remove the engine-to-EDU studs in the sequence shown (1 and 2), install special tool T26004 at this position, then remove the remaining bolts—carefully separate the EDU from the engine to avoid damaging the oil seal on the connecting plate; ⑩ Remove the 4 bolts securing the mount to the EDU and discard them.

Installation: Ensure the environment is clean and dry (prevent oil, water, or debris from entering the transmission interior); After replacing the EDU, perform self-learning in order: TM motor angle self-learning → ISG motor angle self-learning → synchronizer position self-learning → clutch engagement point pressure self-learning, and reset the HCU's completed self-learning count. Raise the vehicle (never work under a vehicle supported only by a jack; it must be supported on safety stands) → Install 4 new mount bolts (63~77)N·m + (85~95)° angle tightening → Clean the mating surfaces → Align T26004 with the 2 engine bolt holes (to prevent damage to the connecting plate oil seal) → With assistance, place the EDU under the vehicle and slowly raise to mate → Engine mounting 8 new bolts 75~90N·m → Cover plate 2 bolts 40~50N·m → Lower tie rod bracket 3 bolts (63~77)N·m + (85~95)° → TM water hose fitting 2 bolts 9~11N·m → ISG water hose fitting 2 bolts 9~11N·m → Install powertrain assembly → Connect negative terminal → Quick path - Learning value adjustment - EDU replacement.

Transmission Oil: Drain / Fill / Level Check

• Drain: Remove the underbody deflector → Place a container under the EDU → Clean around the drain plug → Remove the drain plug and sealing washer and discard (be careful not to damage the housing) → Drain → Clean the drain port → Tighten new drain plug + washer to 30~40N·m;
• Fill: Clean around the fill port → Remove the fill plug and discard the washer → Fill through the fill port → The special filling tool should be used exclusively and not mixed with other vehicle models → New washer + fill plug 30~44N·m;
• Level check: Raise the vehicle → Remove the fill plug and discard the washer → Use a homemade tool made of steel wire approximately 2mm in diameter (50mm<L<60mm) to check the oil level using the bottom of the fill port as the reference plane (keep the vehicle level during measurement) → Measure the vertical distance H between the reference plane of the fill hole and the maximum oil level, repeat 5 times and take the average, determine according to the reference parameters in the table, if out of range, drain and refill → New washer 30~44N·m.

Insulation and Withstand Voltage Test

Warning: The EDU assembly must pass the insulation and withstand voltage test before normal use. ① Inspect the EDU housing, high-voltage wiring harness, and locking clips for damage; ② Set the insulation tester to 1000V range; ③ When testing TM high-voltage insulation, select one phase of the TM-side high-voltage wiring harness, insert the red probe into the connector; ④ Do the same for the ISG side (ensure the probe tip contacts the metal terminal inside the connector); ⑤ Connect the black probe to the EDU assembly housing; ⑥ Press and hold the red probe button for 10 seconds, record the reading, release the button and wait 3 seconds before disconnecting; ⑦ The test result must be ≥5MΩ, otherwise replace the relevant parts and retest.

ISG/TM High-Voltage Wiring Harness

Disassembly: Remove the EDU assembly → Remove the 8 screws securing the ISG/TM high-voltage inspection window cover to the mating plate and discard → Remove the 6 bolts securing the ISG/TM motor high-voltage wiring harness connector to the EDU and discard → Remove the 2 ground wires and 2 studs and discard → Remove the 4 studs + 4 bolts securing the high-voltage wiring harness and discard, then remove the harness.

Installation: Clean the mating surfaces and the EDU connection surface to ensure no foreign matter (cleaning residue must not fall into the transmission) → Apply Loctite 5910 form-in-place gasket to the mating surface (no gaps in the bead, bead width not less than 3mm, height not more than 3mm, bead located inside the bolt holes) → High-voltage wiring harness installation: ISG side 4 new bolts 5.4~6.4N·m, TM side 4 new bolts 21.5~26.5N·m → Ground wires 2 new studs 8.9~10.9N·m → Inspection window cover 8 new screws 5.4~6.4N·m → Perform insulation and withstand voltage test → Install EDU assembly → Use diagnostic scan tool to access VDS → Road test must include at least pure electric, acceleration, parallel, gear shift, and energy recovery conditions.

C1 Clutch

Disassembly: Remove the EDU assembly → Position TPT00232 on the C1 clutch side housing (secured with 2 bolts + 1 nut, not movable, to protect the ISG motor) → Remove the 6 studs securing the C1 flywheel to the ISG motor rotor carrier → Remove the C1 wave spring → C1 clutch driven plate → C1 support ring → C1 diaphragm spring.

Installation: Clean the ISG rotor (cleaning solvent is allowed) → Install the C1 diaphragm spring into the ISG motor rotor carrier → Align the spring notch with the rotor carrier tab, install the C1 support ring onto the transmission (align the notch with the spline position, the spring at the spline must be fully seated) → Install TPT00231 on the input shaft and rotate continuously to check: smooth rotation = support ring seated, damping or binding = not seated, reinstall and adjust → Install the C1 pressure plate → Driven plate onto the input shaft spline → Wave spring → Align the 2 locating pins, then secure the C1 flywheel plate to the rotor carrier, 6 studs 27~33N·m → Remove TPT00232 → With the transmission in D position, rotate the C1 clutch rotor carrier by hand, no obvious binding → Insulation and withstand voltage test → Install EDU assembly → Use diagnostic scan tool to access VDS → Real-time display confirms EDU actual oil pressure is within 35~55bar → Quick path - Learning value adjustment - Clutch engagement point pressure self-learning.

Other Component Quick Reference

• Differential oil seal (left/right): Drain oil → Remove half shaft → Use a flat-blade screwdriver (wrap the tip with tape to prevent damage to the housing) to remove the oil seal; Installation: Clean the groove + spray the lip with specified transmission oil → TPT00118 + hammer to install the new oil seal → Half shaft → Refill oil;
• Vent plug: Remove the service disconnect switch → Remove the vent plug; Installation: tap in vertically with a steel rod;
• Output shaft speed sensor: Service disconnect switch → Turn front wheels fully left → Wiring harness connector → 1 bolt; Installation 9~11N·m;
• Parking brake cable shaft lever: Service disconnect switch → 1 bolt + pry open to secure the parking actuator; Installation 1 bolt 19~25N·m;
• ISG/TM cooling water hose fittings: 2 bolts each 9~11N·m (TM fitting requires removing the PEB tray first).

Safety Warnings

• This article is for technical reference. The EDU is a high-voltage + precision mechanical assembly; service must be performed by qualified technicians (electrician certification + company training authorization) according to OEM specifications.
• Before disassembly, disconnect the negative battery terminal and remove the service disconnect switch; support the assembly with a hydraulic lift device; never work under a vehicle supported only by a jack.
• EDUs that fail the insulation and withstand voltage test are prohibited from use (1000V range, 10 seconds, ≥5MΩ); the high-voltage wiring harness mating surface sealant specifications (width ≥3mm/height ≤3mm/bead inside bolt holes) must be followed.
• After replacing the EDU, the four self-learning steps plus HCU count reset are all mandatory; the road test must cover pure electric/acceleration/parallel/gear shift/energy recovery conditions.

Maintenance Insights

The core of EDU service is "one-time bolts + angle method": the 4 mount bolts and 3 lower tie rod bracket bolts both use (63~77)N·m + (85~95)° torque-plus-angle tightening—these bolts rely on yield point preload, so they must be discarded after one use; reusing old bolts can lead to loosening or even breakage. The order of the four self-learning steps is a hard constraint (TM angle → ISG angle → synchronizer → clutch engagement point pressure), and after completion, the HCU's self-learning count must be reset—if you miss the reset, the HCU will compensate the new hardware with old learned values, which is worse than not learning at all. The two most common pitfalls: the "3mm×3mm bead inside bolt holes" for Loctite 5910 on the high-voltage wiring harness mating surface—a broken bead or pinched wire will cause leaks; the "rotation tool feel" judgment for the C1 support ring—TPT00231 should rotate smoothly to confirm seating; damping or binding means the spring hasn't engaged the spline groove, which is not visible to the eye. The steel wire tool method for oil level check (2mm wire, 50~60mm, 5-time average) is also a practical technique—the standard approach when no dedicated dipstick is available. Finally, remember the five-condition road test checklist: pure electric/acceleration/parallel/gear shift/energy recovery—missing any one condition means the acceptance is incomplete.

---

【This article is for reference only】