What Does P0945 Mean?
DTC P0945 indicates a fault in the hydraulic pump relay circuit, specifically an open circuit condition. The TCM is unable to command the hydraulic pump motor to run because the relay control circuit or the relay itself has an open circuit. Without the relay functioning, the hydraulic pump cannot build pressure for clutch and gear actuation in the automated manual transmission.
Safety Warning
Without the pump relay functioning, the hydraulic pump cannot run and the transmission will lose pressure over time. This can result in inability to shift gears or complete loss of drive. The vehicle may need to be towed if pressure is fully depleted.
Common Causes
30%
Failed hydraulic pump relay (open coil or welded contacts)
25%
Open wiring between TCM and the pump relay control circuit
20%
Blown fuse in the relay power supply circuit
15%
Corroded relay socket or connector terminals
10%
TCM relay driver circuit failure
Diagnostic Steps
1
Step 1: Locate the hydraulic pump relay (typically in the engine compartment fuse/relay box or near the transmission). Check the associated fuse first.
2
Step 2: Remove the relay and test it with a multimeter. Check coil resistance (typically 60-100 ohms) and verify the contacts close when 12V is applied to the coil terminals.
3
Step 3: Inspect the relay socket for corroded, bent, or loose terminals. Clean the socket contacts and verify tight pin engagement.
4
Step 4: With the relay removed, use a multimeter to verify the TCM is providing a ground signal to the relay control terminal when the pump is commanded. If no ground is present, check the wiring back to the TCM.
5
Step 5: Substitute a known-good relay and command the pump. If the pump now operates and builds pressure, the original relay was faulty. Clear codes and verify normal operation.
Estimated Repair Cost
$80 - $400
Parts + labor, varies by vehicle and location
DTC P0945 indicates a fault in the hydraulic pump relay circuit, specifically an open circuit condition. The TCM is unable to command the hydraulic pump motor to run because the relay control circuit or the relay itself has an open circuit. Without the relay functioning, the hydraulic pump cannot bu...
The most common cause of P0945 (Hydraulic Pump Relay Circuit / Open) is: Failed hydraulic pump relay (open coil or welded contacts)
Typical repair costs for P0945 range from $80 to $400, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Without the pump relay functioning, the hydraulic pump cannot run and the transmission will lose pressure over time. This can result in inability to shift gears or complete loss of drive. The vehicle may need to be towed if pressure is fully depleted.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P0945 to identify the root cause.
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Quick Info
Category
Powertrain
System
Transmission / Clutch Hydraulic System
Difficulty
Type
Generic (SAE)
Recommended Tools
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