DTC chart

[Lee S71]

Hope someone can help me track down some error code definitions???

I have an issue with my dual AC not blowing any heat on the drivers side. I have completed the INDICATOR CHECK / SENSOR CHECK / ACTUATOR CHECK which is accessed by pressing AC AUTO button and RECIRCULATE button simultaneously whilst turn the ignition from OFF to ON. The sensor check has returned error codes 21 and 24 - what these mean I have no idea.

The instructions I have say "refer to the DTC chart (see page AC-39)" but no link is supplied to the relevant DTC chart.

Does anybody out there have a link to the DTC chart, or can you supply a definition to these codes? It's a Sunday afternoon so I cant call my local dealer, and I would really like to get some idea how to fix it before I get up at 5am tomorrow morning and freeze my ***** off driving to work.

Hope someone out there can help

from "Frozen in Bedford"

[Lee S71]

I've been advised these codes refer to the solar sensor - The car was in the shade when I checked it, and no error codes displayed when the car was checked again in direct sunlight.

Does anybody have any experience of this or can advise how I can keep myself warm on the drive to/from work in these cold conditions?

[paul9]

If the heat still works on the passenger side, that would usually be a blend door problem. If both sides stay cold, then check the engine coolant levels. You may have a leak or a blockage which needs to be fixed. There were some AC diagnostic codes on the forum, but I couldn't point you to the post or guide they were in.

[paul9]

Try shutting off the driver side system and vents and hijack the passenger side system to point across to you as a possible workaround until you get to the cause of the problem, if the passenger side still blows hot.

[flash22]

What does the system do if you take it off dual mode ? There should be a PTC thermistor that detects the heat output

Some thermals and a hot water bottle should cure the freezing 😉

tbh its one of those issues you need to see in person or have the data from

The DTC's are

B1421/21

B1421/24

• Solar sensor
• Harness and connector between solar
sensor and air conditioning amplifier
• Air conditioning amplifier

These are likely a symptom and not the issue, If in doubt turn it off, and back on again......................................

I meant disconnect the Battery for 15-20 min's