FAQ
TL;DR: On 2010 VW Crafter 2.0 TDI, code 4875 often flags the EGR-cooler auxiliary pump; in one case, 3 aftermarket pumps failed and “the original pump solved the problem.” [Elektroda, beryas, post #19788627]
Why it matters: This FAQ helps owners and techs fix limp mode with flashing glow-plug and CEL tied to error 4875 on Crafter/Transporter.
Quick Facts
- Symptom set: CEL on, glow-plug light flashing, limp mode—even with just ignition on. [Elektroda, Rykielhome, post #19785197]
- Fault text users saw: “4875” / “coolant pump B” / “additional water pump for exhaust gas cooler.” [Elektroda, pawcio013, post #16775106]
- Aftermarket pump price: approx. 200–300 PLN; OEM pump near 700 PLN reported. [Elektroda, beryas, post #19788627]
- Wiring tip: inspect blue wire ~15–20 cm from pump connector for intermittent break. [Elektroda, CAR pass, post #19787922]
- Measured signals: +12 V on two pins and ~3.4 V signal to CAN on the third, per user test. [Elektroda, Rykielhome, post #19788099]
What does error 4875 mean on a VW Crafter 2.0 TDI?
Owners report 4875 as the auxiliary coolant pump for the EGR cooler (“coolant pump B”). When it faults, the ECU triggers a check-engine light, flashing glow-plug lamp, and limp mode. This aligns with VCDS showing 4875-ROD and descriptions like “additional water pump for the exhaust gas cooler.” The pump may still spin, yet the control or verification logic flags a fault. Replacement with a proven OEM unit has cleared the code for several users. [Elektroda, pawcio013, post #16775106]
Why didn’t my new aftermarket pump clear 4875?
Multiple reports say new aftermarket pumps did not satisfy diagnostics, while an OEM pump did. One user tried two Hepu pumps without success; switching to the original part fixed the fault and restored power. Another reported three new pumps tried before resolving it with OEM. As one tech put it, “the original … solved the problem.” This suggests the ECU’s plausibility checks can reject some aftermarket units. [Elektroda, beryas, post #19788627]
Can wiring cause the 4875 code even if the pump spins?
Yes. A known weak spot is a blue wire about 15–20 cm from the pump connector. An intermittent break there can trigger the fault despite pump operation. Inspect, tug-test, and repair any damaged conductors or insulation. Clear codes and confirm stable operation after repair. This simple harness fix has helped users where parts swaps failed. [Elektroda, CAR pass, post #19787922]
How do I test the pump connector signals safely?
With ignition on, users measured +12 V on two pins and about 3.4 V on the signal/CAN pin. Verify battery voltage supply, ground integrity, and the signal line. Use a quality multimeter and back-probe; avoid piercing insulation when possible. If values deviate, diagnose the harness before replacing components. Document readings to compare after repairs. [Elektroda, Rykielhome, post #19788099]
Is limp mode normal with this fault?
Yes. The flashing glow-plug light and limp mode can appear immediately after key-on, even before starting. Users reported loss of power persisting until the underlying issue was fixed. Once the OEM pump was installed or wiring corrected, the warning cleared and full performance returned. This behavior matches protective cooling logic. [Elektroda, Rykielhome, post #19785197]
What’s the fastest practical fix for 4875 on a Crafter?
Start by inspecting and repairing the short harness section near the pump. If wiring checks out, install an OEM auxiliary pump rather than an aftermarket unit. Users consistently report the OEM pump clears the code and restores power, while cheaper replacements often fail diagnostics. “Original pump solved the problem,” summarized one owner. [Elektroda, Rykielhome, post #19798576]
Do aftermarket pumps really fail more here?
In-thread data points say yes. One case: two Hepu pumps failed diagnostics; OEM fixed it. Another: three aftermarket pumps did not resolve the code. That is a 0% success rate across five aftermarket attempts in those reports. While limited, it’s a clear signal for this platform’s control strategy. [Elektroda, beryas, post #19788627]
Could a head-gasket issue be related to 4875?
One user noted the error persisted after pump replacement, then disappeared following a head-gasket replacement. They were unsure if it was related. Treat this as an edge case. Rule out wiring and pump first; consider broader cooling-system faults only if primary fixes fail. [Elektroda, SkyNet1989, post #17214099]
What is the ‘CAN’ wire mentioned at the pump?
In this thread, the ‘CAN’ reference is the pump’s signal line observed at about 3.4 V with ignition on. That reading indicated a live control/signal circuit. If the CAN/signal line is open or shorted, the ECU may log 4875 and enter limp mode. Validate continuity and repair as needed. [Elektroda, Rykielhome, post #19788099]
Does pump run-on after shutdown indicate anything?
One user observed the aftermarket pump ran noticeably longer after key-off than the OEM unit. After installing the original pump, run-on time shortened, and the fault cleared. Excessive run-on can hint at control mismatch or internal pump electronics differences that fail plausibility checks. [Elektroda, beryas, post #19788627]
Is there a software workaround to bypass limp mode?
A contributor stated you can disable diagnostics for this pump in software, removing the associated power limitation. This is a non-OEM modification and carries risk for engine and emissions durability. Prioritize proper repair before considering software changes. [Elektroda, damdam, post #19785320]
How can I fix 4875 step-by-step?
- Scan with VCDS, confirm 4875 and record freeze-frame data. 2. Inspect harness; especially the blue wire ~15–20 cm from the connector; repair as needed. 3. If wiring is sound, fit an OEM auxiliary EGR-cooler pump, clear codes, and road-test. [Elektroda, CAR pass, post #19787922]
Does this issue affect other VAG vans like the VW T5?
Yes, a T5 owner reported the same error with reduced power and asked about a home fix. The diagnostic path remains similar: verify wiring, then install a known-good OEM pump. Expect the same warning lights and limp behavior until resolved. [Elektroda, WojciechKaminski, post #19621404]
Why does 4875 appear even without starting the engine?
Users saw the glow-plug light flash and limp mode right after switching the ignition on. The ECU checks the auxiliary pump circuit at key-on. If plausibility fails, it sets the fault immediately, regardless of engine running state. Fixing wiring or fitting OEM cleared this behavior. [Elektroda, Rykielhome, post #19785197]
Where can I get a cooling system diagram for the Crafter?
One owner asked for the diagram after resolving the fault. The thread doesn’t include a schematic. Your best path is OEM service literature or dealer EPC for hose routing and pump position relative to the EGR cooler. [Elektroda, Rykielhome, post #19798576]
