10-3.Trouble criterion of main parts

MUH-GA20VB - E1

MUH-GA25VB - E1

MUH-GA35VB - E1

Part name

Check method and criterion

Figure

Measure the resistance with a tester. (Part temperature –10°C ~ 40°C)

Defrost

 

Normal

 

Abnormal

 

 

thermistor

 

 

 

 

 

 

 

 

 

 

 

(RT63)

 

5kΩ ~ 60kΩ

Open or short-circuit

 

 

 

 

 

 

Compressor

Measure the resistance between the terminals with a tester.

 

 

(MC)

(Coil wiring temperature –10°C ~ 40°C)

 

 

WHT C

INNER

 

 

 

 

 

 

 

 

 

PROTECTOR

 

 

Normal

 

 

 

P

MUH-GA20/GA25VB

 

 

 

Abnormal

AUX. MAIN

 

 

 

 

150i 5°C OPEN

 

MUH-GA20VB MUH-GA25VB

MUH-GA35VB

 

 

 

 

S

RBLK

90i10°C CLOSE

 

 

 

 

 

MUH-GA35VB

C-R

3.41~4.18Ω

2.99~3.67Ω

2.46~3.01Ω

 

 

RED

Open or short-circuit

 

 

155i 5°C OPEN

C-S

5.41~6.63Ω

4.02~4.92Ω

2.96~3.63Ω

 

 

 

 

 

90i10°C CLOSE

 

 

 

 

 

 

 

 

 

 

Outdoor fan

Measure the resistance between the terminals with a tester.

 

(Coil wiring temperature –10°C ~ 40°C)

 

 

motor

 

 

 

 

 

 

MAIN

(MF)

 

 

 

 

Color of

Normal

Abnormal

AUX.

 

 

lead wire

MUH-GA20VB MUH-GA25/GA35VB

 

INNER FUSE

 

FUSE

 

 

145i 2°C

WHT-BLK

323 ~ 396 Ω

189 ~ 233 Ω

Open or short-circuit

 

CUT OFF

BLK-RED

241 ~ 296 Ω

270 ~ 332 Ω

 

 

BLK RED WHT

 

 

10-4. Troubleshooting flow

Compressor and/or outdoor fan motor doesn’t operate.

P INNER PROTECTOR

A Check of outdoor unit

Start

 

 

 

 

 

 

 

 

 

 

 

 

 

Is the switch SW2- on the

No

 

Change the switch SW-2-

indoor electronic control

 

 

on the indoor electronic control

 

 

P.C. board set to MUH type?

 

 

P.C. board to MUH type.

 

Yes

 

 

 

 

 

 

 

 

Operate the unit in COOL or HEAT mode by pressing the EMERGENCY OPERATION switch. 3-minute time delay works.

Test run operation operates for 30 minutes.

Compressor doesn't operate.

Is there 5V DC between J205 + –J101–

on

 

 

No

Is there 230V AC between 4 on the

 

 

 

 

 

 

compressor contactor (52C) and

the deicer P.C. board?

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

TAB20 on the deicer P.C. board?

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Yes

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Yes

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Is there 230V AC between 3 on the

No

Replace the

 

 

Replace the

 

compressor contactor (52C) and

deicer P.C.

 

 

 

 

 

 

 

 

deicer P.C. board.

 

on the outdoor terminal block (TB1)?

 

 

 

board.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Yes

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Check the compressor and compressor

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

capacitor, and rectify the connecting wire.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Outdoor fan motor

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

doesn't operate.

 

 

 

 

 

 

 

No

Is there 230V AC between 4 on the

 

 

 

 

 

 

 

 

 

 

 

 

Is there 5V DC between J205 + –J101– on

 

 

 

 

 

 

 

 

 

compressor contactor (52C) and

 

the deicer P.C. board?

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

TAB 20 on the deicer P.C. board?

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Yes

 

 

 

 

 

 

 

 

 

 

 

 

 

Yes

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Check the outdoor fan motor

 

 

 

 

 

 

 

 

 

 

 

Replace the

 

 

 

and rectify the connecting

 

 

 

 

 

 

 

 

 

 

 

deicer P.C. board.

 

 

 

wire.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

No

No

Rectify the indoor and outdoor connecting wire.

No

Is there 230V AC between –

on the outdoor terminal block (TB1)?

Yes

Rectify the connecting wire.

Rectify the indoor and outdoor connecting wire.

No

Is there 230V AC between – on the outdoor terminal block (TB1)?

Yes

Rectify the connecting wire.

24

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Image 24
Pioneer MUH-GA35VB, MUH-GA25VB, MUH-GA20VB service manual Check of outdoor unit
Page 23 Page 25

MUH-GA20VB, MUH-GA25VB, MUH-GA35VB specifications

The Pioneer MUH-GA25VB, MUH-GA35VB, and MUH-GA20VB are a trio of advanced multimedia head units designed to enhance the in-car experience with a blend of cutting-edge technology and user-friendly features. Each model offers a unique set of functionalities tailored to meet varying needs and preferences, while maintaining high standards in audio performance and connectivity.

The MUH-GA25VB serves as a versatile entry point into Pioneer’s lineup. It features a sleek 6.2-inch touchscreen display that provides intuitive controls and easy access to music and navigation. With Bluetooth connectivity, users can enjoy hands-free calling and wireless audio streaming, enhancing safety and convenience on the road. The built-in FM/AM tuner and compatibility with USB and AUX sources allow for diverse listening options. Moreover, the MUH-GA25VB supports various audio formats, ensuring playback flexibility.

Stepping up, the MUH-GA35VB incorporates enhanced sound tuning features, including a 13-band graphic equalizer that allows users to tailor audio output to their liking. The larger 7-inch touchscreen provides an immersive interface, making navigation through multimedia content seamless. This model also supports Apple CarPlay and Android Auto, enabling users to integrate their smartphones for a more connected experience. The voice control feature allows for hands-free operation of navigation and music, making it an ideal choice for tech-savvy drivers.

At the top of the range, the MUH-GA20VB boasts superior connectivity and sound quality. It is equipped with a high-resolution audio playback capability, supporting formats up to 192 kHz/24-bit for audiophiles seeking the best sound fidelity. With dual USB ports, users can connect multiple devices simultaneously, allowing for easier management of music and charging. The hardware enhancements include high-performance DACs that result in clearer and more detailed audio reproduction. Furthermore, this model features a customizable interface, enabling users to tailor the look of the head unit to match their vehicle’s interior.

Collectively, the Pioneer MUH series – MUH-GA25VB, MUH-GA35VB, and MUH-GA20VB – presents a compelling case for anyone looking to upgrade their vehicle’s audio and multimedia capabilities. They combine sophisticated technology with user-centric designs, ensuring a remarkable in-car experience that caters to a diverse range of audiophiles and tech enthusiasts alike. Whether you prioritize straightforward functionality or advanced features, there is a model in this lineup to suit every taste and requirement.
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