B151B49

Code

VOLVO B — Body

Parking Cooler Control Unit. Internal Electronic Failure

Brand: VOLVO

Type: B — Body

Views: UK: 19 EN: 31 RU: 17

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Page language: EN

Parking cooler (auxiliary cooler) does not operate or cycles incorrectly
DTC B151B49 stored in body/comfort module or parking cooler control unit memory
Warning message or lamp on instrument cluster depending on vehicle configuration
No response to cooler controls in the vehicle menus
Reduced cooling performance when parked
Intermittent operation or sudden loss of cooler function

Read freeze frame and full module memory with Volvo VIDA or equivalent scan tool; note companion codes and history
Visually inspect module and connector for corrosion, water ingress, damage or oil/contamination
Check fuses and relays related to parking cooler power feed
Measure battery voltage at vehicle and at module connector (expected ~11–14 V depending on state)
Verify good ground at module pin to chassis (near 0 Ω recommended)
Check CAN/LIN communication presence at module connector (idle ~2.5 V on CAN lines) and check for bus errors or bus-off conditions

Battery supply voltage to module: ~11–14 V (vehicle off vs on conditions)
Switched ignition or accessory feed: ~12 V when ignition/accessory on (if applicable)
Ground continuity: very low resistance (near 0 Ω) between module ground pin and chassis
CAN High/Low idle voltage: ~2.5 V each (differential ~0 V) with normal bus activity when engine running or key on
Module response to diagnostic request: should acknowledge and return data/parameters via VIDA/scan tool
Ambient/evaporator temperature sensor readings: plausible ranges (e.g., -40 to +85 °C depending on sensor)

Connect VIDA or manufacturer-level scan tool and read all stored and pending codes from parking cooler module and body modules; record freeze frame and reference companion codes
Clear the code and see if it returns; note conditions and driving/park states when it reappears
Inspect the parking cooler control unit and connector for corrosion, moisture, physical damage, or signs of rodent/wear damage
Check related fuses and relays; replace any blown fuses and retest
With battery connected, backprobe module power and ground pins: verify constant battery feed and a solid ground (measure voltage and resistance)
Verify communication on CAN/LIN network with scope or scan tool: check for valid frames and no bus-off; check for other modules reporting communication faults
Perform wiggle test on harness and connector while monitoring power/ground/communications to detect intermittent faults
If wiring and power/ground/communications are good but fault persists, check for software updates and reflash module per dealer/service instructions
If all external checks pass and intermittent or permanent internal fault remains, consider replacement of the parking cooler control unit following manufacturer replacement and coding procedures
After repair or replacement, clear codes and perform functional test of the parking cooler; confirm no reoccurrence and return to normal operation

⚠️ Status

Internal electronic failure detected in Parking Cooler Control Unit — module fault, power/ground or communication error possible.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1.5 - 3.0 hours

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