How can this help me?
Interrogating the ECU will hopefully point you in the right direction for your fault. If not, at least you'll know what the ECU is doing and what IT thinks is wrong!
When should I do this?
How do I find out if I have any error codes?
Turn the ignition key so that the car doesn't start but powers up the instruments. On the right hand side in the engine bay is a connector marked "diagnostic". Open the protective flap. On the inside of the lid is a diagram showing the location of the pins and a letter identifying them e.g. OX - (Lambda sensor). Locate the TE1 and E1 terminals and connect these together with any old piece of wire or e.g. a paper clip.
Note that the ST165 designation is different, these 2 terminals are marked as "T and E1".
How do I interpret the error codes?
Once you have bridged the two terminals together look at the orange engine check light on the dashboard on the right hand side of the steering wheel. This light will flash to indicate any error codes. If this flashes regularly then everything is normal as far as the ECU is concerned. If there is a series of flashes or codes then interpret these as follows:
E.g. for code 54 - 5 flashes, small pause, 4 flashes, longer pause, then 5 flashes, small pause, 4 flashes- this repeats...
*.*.*.*.* | .. | *.*.*.* | ..... | *.*.*.*.* | .. | *.*.*.* | ..... |
5 | 4 | 5 | 4 |
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Click the above icon to download a video of a code 54, followed by a code 42 error. The video is from a 205, but the clip
is also applicable to the 165 and 185 The video is a *.mov file that can be played by a QuickTime Player. Click here to download the free QuickTime player |
Error code listing
Code | Description | What to do? |
12 - RPM | No G1, G2 or NE signal to ECU, open in G- circuit | Starting related, check distributor, starter, ECU. The dizzy is connected to the loom via a plug awkwardly placed under the dizzy - check this, and the dizzy wiring |
13 - RPM | No "NE" signal to ECU above 1000 rpm | Check distributor, ECU |
14 - IGN | No "IGF" signal to ECU 8 times | Check igniter, ignition coil, ECU and IGT wire to igniter. Can be caused by wire feed into the coil. The IGF signal is fed back to the ECU to inform the ECU that the igniter is "ok" |
16 - CPU | ECU duff | Repair or find a new ECU |
21 - O2 | Detection of oxygen sensor deterioration | Check oxygen sensor |
22 - WTR | Open or short in Water Temp Sensor | Check/test Water Temp Sensor and wiring |
23 - MAT | MAT Fault | Check intake air temp sensor connector and functioning correctly |
24 - AIR | Open or short circuit in Air Intake Temp Sensor | Check Air Temp Sensor within intake filter housing |
25 - O2 | Excessive Lean Air Fuel Ratio | Check O2 sensor, fuel system. Replace fuel filter. Check FPR connection and water temp sensor |
31 - PIM | Open circuit or short in MAP sensor | Test or replace MAP sensor |
34 - PIM | Fuel cut due to excessive turbo pressure | Check Wastegate, Wastegate actuator, Wastegate Hose, Turbo Pressure Sensor |
41 - TPS | Open or short circuit in VTA signal | Test Throttle Position Sensor - article |
42 - SPD | No "SPD" signal over 8 seconds driving | Check Vehicle Speed Sensor, SLD (if fitted) and wiring |
43 - STA | No starter signal over 800 RPM starting | Check Ignition Switch |
51 - A/C | Aircon malfunction | Check Throttle Position Sensor - article |
52 - KNK | Open or short circuit in Knock Sensor | Check for broken/brittle wire from KS to ECU, check sensor correctly torqued up, check sensor terminal not covered with oil/shorted out, replace sensor, shake sensor - it shouldn't rattle! There should be no continuity between the centre pin and the body of the KS |
53 - KNK | Knock control in ECU faulty | ECU |
54 - INT | Intercooler Coolant Low or Pump Failure | Top up IC fluid reservoir, test IC water level sensor, test IC water pump. Tip - run car with IC cap removed, blip throttle, watch water level drop, add fluid to max level, swiftly replace cap - this also indicates that the pump runs |
I have more than one error code! Help!
Multiple error codes will be shown as e.g. 54 then 21, and will then repeat 54 then 21... Some faults bring up more than one error code. Look at what faults are being shown and try to think how they are all connected. Normally only one device has failed/gone weird and that is the cause of the 2 or 3 fault codes.
Yeah okay I think I've fixed it - how do I make the stored fault go away?
Some codes are cleared when you switch the ignition off, others have to be cleared by removing the power to the ECU. This is done by either removing a lead from the battery, (pain in the arse), or simply pulling the 15A ECU fuse located in the engine bay fuse box for 10 seconds ish.
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Identify the engine bay fuse box... | ...remove the cover to the fuse box in the engine bay... | ...under the lid is the layout for the fuses... | ...remove the fuse to reset the ECU |