diff --git a/selfdrive/test/process_replay/README.md b/selfdrive/test/process_replay/README.md
index 7e92717f9d..3add95f0a0 100644
--- a/selfdrive/test/process_replay/README.md
+++ b/selfdrive/test/process_replay/README.md
@@ -12,6 +12,7 @@ Currently the following processes are tested:
 * radard
 * plannerd
 * calibrationd
+* ubloxd
 
 ## Forks
 
@@ -19,6 +20,6 @@ openpilot forks can use this test with their own reference logs
 
 To generate new logs:
 
-`./update-refs.py --no-upload`
+`./update_refs.py --no-upload`
 
 Then, check in the new logs using git-lfs. Make sure to also include the updated `ref_commit` file.
diff --git a/selfdrive/test/process_replay/compare_logs.py b/selfdrive/test/process_replay/compare_logs.py
index 8cb4b2453f..397e6de564 100755
--- a/selfdrive/test/process_replay/compare_logs.py
+++ b/selfdrive/test/process_replay/compare_logs.py
@@ -3,7 +3,6 @@ import bz2
 import os
 import sys
 import numbers
-
 import dictdiffer
 
 if "CI" in os.environ:
@@ -59,6 +58,7 @@ def compare_logs(log1, log2, ignore_fields=None, ignore_msgs=None, tolerance=Non
     ignore_msgs = []
 
   log1, log2 = [list(filter(lambda m: m.which() not in ignore_msgs, log)) for log in (log1, log2)]
+
   if len(log1) != len(log2):
     raise Exception(f"logs are not same length: {len(log1)} VS {len(log2)}")
 
diff --git a/selfdrive/test/process_replay/process_replay.py b/selfdrive/test/process_replay/process_replay.py
index 3b05b3871f..3676f76fe3 100755
--- a/selfdrive/test/process_replay/process_replay.py
+++ b/selfdrive/test/process_replay/process_replay.py
@@ -4,6 +4,7 @@ import os
 import sys
 import threading
 import importlib
+import time
 
 if "CI" in os.environ:
   def tqdm(x):
@@ -18,13 +19,12 @@ import cereal.messaging as messaging
 from common.params import Params
 from cereal.services import service_list
 from collections import namedtuple
-
+from selfdrive.manager import managed_processes
 # Numpy gives different results based on CPU features after version 19
 NUMPY_TOLERANCE = 1e-7
 
 ProcessConfig = namedtuple('ProcessConfig', ['proc_name', 'pub_sub', 'ignore', 'init_callback', 'should_recv_callback', 'tolerance'])
 
-
 def wait_for_event(evt):
   if not evt.wait(15):
     if threading.currentThread().getName() == "MainThread":
@@ -206,6 +206,15 @@ def calibration_rcv_callback(msg, CP, cfg, fsm):
     recv_socks = ["liveCalibration"]
   return recv_socks, fsm.frame == 0 or msg.which() == 'cameraOdometry'
 
+def ublox_rcv_callback(msg):
+  msg_class, msg_id = msg.ubloxRaw[2:4]
+  if (msg_class, msg_id) in {(1, 7 * 16)}:
+    return ["gpsLocationExternal"]
+  elif (msg_class, msg_id) in {(2, 1 * 16 + 5), (10, 9)}:
+    return ["ubloxGnss"]
+  else:
+     return []
+
 CONFIGS = [
   ProcessConfig(
     proc_name="controlsd",
@@ -285,9 +294,27 @@ CONFIGS = [
     should_recv_callback=None,
     tolerance=NUMPY_TOLERANCE,
   ),
+  ProcessConfig(
+    proc_name="ubloxd",
+    pub_sub={
+      "ubloxRaw": ["ubloxGnss", "gpsLocationExternal"],
+    },
+    ignore=["logMonoTime"],
+    init_callback=None,
+    should_recv_callback=ublox_rcv_callback,
+    tolerance=None,
+  ),
 ]
 
 def replay_process(cfg, lr):
+  proc = managed_processes[cfg.proc_name]
+  if isinstance(proc, str):
+    return python_replay_process(cfg, lr)
+  else:
+    return cpp_replay_process(cfg, lr)
+
+
+def python_replay_process(cfg, lr):
   sub_sockets = [s for _, sub in cfg.pub_sub.items() for s in sub]
   pub_sockets = [s for s in cfg.pub_sub.keys() if s != 'can']
 
@@ -353,3 +380,31 @@ def replay_process(cfg, lr):
 
         recv_cnt -= m.which() in recv_socks
   return log_msgs
+
+def cpp_replay_process(cfg, lr):
+  sub_sockets = [s for _, sub in cfg.pub_sub.items() for s in sub]  # We get responses here
+  pm = messaging.PubMaster(cfg.pub_sub.keys())
+  sockets = {s : messaging.sub_sock(s, timeout=1000) for s in sub_sockets}
+
+  all_msgs = sorted(lr, key=lambda msg: msg.logMonoTime)
+  pub_msgs = [msg for msg in all_msgs if msg.which() in list(cfg.pub_sub.keys())]
+
+  manager.prepare_managed_process(cfg.proc_name)
+  manager.start_managed_process(cfg.proc_name)
+
+  time.sleep(1)  # We give the process time to start
+
+  log_msgs = []
+  for s in sub_sockets:
+    messaging.recv_one_or_none(sockets[s])
+
+  for msg in tqdm(pub_msgs):
+    pm.send(msg.which(), msg.as_builder())
+    resp_sockets = sub_sockets if cfg.should_recv_callback is None else cfg.should_recv_callback(msg)
+    for s in resp_sockets:
+      response = messaging.recv_one(sockets[s])
+      if response is not None:
+        log_msgs.append(response)
+
+  manager.kill_managed_process(cfg.proc_name)
+  return log_msgs
diff --git a/selfdrive/test/process_replay/ref_commit b/selfdrive/test/process_replay/ref_commit
index 6053df0f66..426b01c99f 100644
--- a/selfdrive/test/process_replay/ref_commit
+++ b/selfdrive/test/process_replay/ref_commit
@@ -1 +1 @@
-d6364d7b9c574790642c273d87ee2e8e46664aab
\ No newline at end of file
+1ca0db37c9fab1328fe1f86cc884b9bc7123aaee
\ No newline at end of file