Roewe Plug-in Hybrid Power Electronics Box (PEB) Removal and Installation Guide

Fault Background

The PEB (Power Electronics Box) of the Roewe plug-in hybrid integrates the ISG/TM dual motor controllers and is a high-voltage component. Its removal and installation follow strict vehicle high-voltage protocols: training threshold, disconnect 12V, remove manual service disconnect (MSD), inspect insulating gloves, prevent liquid splashing, wait 5 min for capacitor discharge. The manual provides a complete 15-step removal and 12-step installation procedure, with voltage verification (multimeter DC range >400V) as a mandatory checkpoint before further disassembly. Additionally, the PEB tray and bracket have separate removal/installation procedures (19~25N·m torque range). This article is organized as a maintenance guide.

PEB Removal (15 Steps)

High-voltage discipline (three warnings): ①Personnel who have not participated in the high-voltage system knowledge training for this vehicle model are prohibited from disassembling the high-voltage system (including high-voltage battery pack, e-drive transmission, power electronics box, high-voltage wiring harness, electric A/C compressor, on-board charger, AC charging port and charging cable); ②Before disassembling high-voltage components, the 12V power supply and the manual service disconnect on the high-voltage battery pack must be disconnected; ③Before operation, wear labor protection supplies, insulating gloves (check for damage before wearing to ensure no insulation failure), and high-voltage insulating shoes; during installation and removal, prevent brake fluid, washer fluid, coolant, etc. from entering or splashing onto high-voltage components.

1. Turn off the ignition key, let the vehicle sit for more than 5 minutes (high-voltage capacitors need time to discharge);
2. Disconnect the battery negative terminal;
3. Remove the manual service disconnect (MSD);
4. Drain the PEB coolant;
5. Disconnect the inlet and outlet water pipes on the PEB;
6. Disconnect the connector to the engine compartment fuse box wiring harness;
7. Remove the 3 bolts (1) that secure the ISG motor and TM motor high-voltage wiring harnesses to the PEB, and disconnect the high-voltage harness connectors;
8. Voltage verification: Set the multimeter to DC voltage, range >400V, measure between the terminals of the high-voltage connectors on the PEB, between terminals and ground, and between terminals inside the high-voltage connectors on the harness side to check for high voltage—only proceed if the voltage is 0;
9. Remove the 4 bolts (2) that secure the PEB assembly to the PEB tray;
10. Disconnect the 2 low-voltage connectors on the left side of the PEB;
11. With assistance, lift the PEB and disconnect the high-voltage connector underneath;
12. Remove the 1 nut that secures the power electronics box ground wire to the PEB;
13. Remove the PEB;
14. Remove the PEB frame (shield)—this frame (shield) can be replaced separately.

PEB Installation (12 Steps)

Prerequisite discipline: Before the high-voltage system (high-voltage battery pack, e-drive transmission, power electronics box, high-voltage wiring harness, electric A/C compressor, on-board charger, AC charging port and charging cable) is fully installed (including all wiring routing and securing), the battery negative cable must remain disconnected, and the manual service disconnect must remain in the disconnected position.

1. Place the PEB frame (shield) on the PEB housing according to the screw hole positions;
2. Secure the power electronics box ground wire to the PEB, install 1 nut, tighten to 7~10N·m and check torque;
3. Place the PEB on the tray and connect the high-voltage connector underneath the PEB;
4. Connect the 2 low-voltage connectors on the left side of the PEB;
5. Secure the PEB to the tray, install 4 bolts, tighten to 19~21N·m and check torque;
6. Connect the ISG motor and TM motor high-voltage harness connectors, secure the harness to the PEB with 3 bolts, tighten to 4~6N·m and check torque;
7. Connect the connector to the engine compartment fuse box wiring harness;
8. Connect the inlet and outlet water pipes on the PEB;
9. Fill the PEB coolant;
10. Connect the battery negative terminal;
11. Perform self-learning operation on the PEB (see the PEB self-learning chapter in the Module Self-Learning and Programming Manual);
12. Note: If the vehicle fails to start, try disconnecting the battery and reconnecting it, then retry.

PEB Tray Removal and Installation

Removal: Remove the PEB → Remove the 2 bolts (1) that secure the ISG motor and TM motor high-voltage wiring harnesses to the PEB tray → Remove the 2 bolts (2) that secure the pedestrian warning speaker to the tray, move the speaker aside → Without draining coolant and without disconnecting hoses, remove the 1 bolt that secures the coolant expansion tank to the tray, move the tank aside → Remove the 2 bolts (4) that secure the PEB tray to the tray bracket → Remove the 1 bolt (2) that secures it to the transmission mount → Remove the 1 nut (3) that secures it to the body and release the wiring harness clips → Remove the tray.

Installation: Body nut → Tray bracket 2 bolts → Transmission mount bolt → Expansion tank mounting bolt → Pedestrian warning speaker 2 bolts → Motor high-voltage harness 2 bolts—all 19~25N·m range and check torque, finally reinstall the PEB (sequence as in the previous section).

PEB Bracket Removal and Installation

Removal: Remove PEB → Remove PEB tray → Remove the 3 bolts that secure the PEB bracket to the body → Remove the bracket.

Installation: Secure the bracket to the body with 3 bolts, 19~25N·m and check torque → Reinstall PEB tray → Reinstall PEB.

Key Parameter Quick Reference

Safety Warnings

• This article is for technical reference. The PEB is a high-voltage component; removal and installation must be performed by personnel trained in the high-voltage system knowledge of this vehicle model.
• Double disconnect: Before operation, disconnect 12V + remove MSD; keep the negative terminal and MSD disconnected until installation is complete.
• Voltage verification checkpoint: After power-off and standing, still use a multimeter DC range (>400V) to confirm no high voltage between terminals, to ground, and on the harness side.
• Drain coolant before removing water pipes; during tray removal/installation, the expansion tank does not require draining or hose disconnection, to prevent liquid from entering high-voltage components.
• After reinstallation, PEB self-learning must be performed; otherwise, motor control may report errors or fail to start.

Maintenance Insights

This PEB procedure clearly explains the three "hidden checkpoints" of high-voltage removal and installation: Standing for 5 minutes is the physical time for capacitor discharge (not a formality—the high-voltage capacitors inside the PEB still store high voltage after power-off); Voltage verification is the only reliable confirmation method, with range >400V, measuring all three locations (between terminals, to ground, and on the harness side), and only proceeding when voltage is zero; Installation discipline is "negative terminal and MSD restored last"—keep them disconnected until all high-voltage components are installed, to avoid accidental power-up in a semi-assembled state. The torque values are also worth remembering: ground nut 7~10 (smallest, to prevent stripping the ground stud), motor high-voltage harness bolts 4~6 (to prevent crushing high-voltage terminals), PEB to tray 19~21, each protecting different components. Finally, don't forget self-learning: after PEB replacement, without self-learning, the ISG/TM motor resolver and phase information is missing, and the vehicle may refuse to power up—the manual also provides a fallback tip "if it fails to start, disconnect the battery and reconnect to retry", which is the most practical emergency action on site.

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【This article is for reference only】