← Back to list

2007 Mazda 5 P0148 Code: Causes and Troubleshooting Guide

Model: 2007 mazda 5 Fault Code: P0148 Posted: 2009-08-15 09:21

Hi everyone, I'm new to this forum and recently purchased a 2007 Mazda 5 used. I'm currently seeing a P0148 diagnostic trouble code, which my auto parts store identified as indicating a low coolant temperature. The warning light appeared just a few days ago, and I've checked the coolant level—it's at full capacity. Since I didn't receive an owner's manual with the car, I'm unsure about the correct type of coolant to use; currently, the fluid is green. I've searched through previous posts but haven't found anything directly related. The issue seems to be intermittent, and the vehicle runs fine otherwise. I'm wondering where to start troubleshooting. Could a stuck thermostat be the cause? Is there any specific coolant specification for Mazda 5 models from that year? Any advice or insights would be greatly appreciated.

Related fault codes
P0148
Comments (4)
Anonymous 2009-08-15 11:14

Check if the coolant level is at the proper full mark. A low level can trigger a P0148 code due to inaccurate temperature readings.

Anonymous 2009-08-15 11:48

The coolant level is indeed full—this was my first check when the issue appeared. I bought the car used about a month ago and didn't receive an owner's manual. The current coolant is green. What type of coolant should I use for a 2007 Mazda 5? Is there a specific mix or formulation recommended by Mazda?

Anonymous 2009-08-15 12:44

Even though it's currently warm season, have you noticed reduced heater performance when the car is set to full heat? If yes, that could indicate a thermostat stuck open. A malfunctioning thermostat can cause inaccurate engine temperature readings and trigger P0148. I'd recommend visiting your local dealer for a diagnostic check—Mazda may have technical service bulletins (TSBs) related to this code.

Anonymous 2009-08-15 13:42

Thanks—I've tested the heater, and it's functioning normally. I'll wait until later in the season when temperatures drop to see if any changes occur. The car runs fine otherwise, but the P0148 code persists. I plan to visit the dealer this week for a proper inspection.