Turn the ignition to “on” (do NOT start the car), now press the gas pedal in and out 5 times quickly. The check engine light will proceed to flash once to let you know it has initiated the stomp test, then it will display codes as a sequence of 4 numbers; for instance First number: flash, pause, Second number: flash flash, pause, third number: flash flash flash, pause, forth number: flash. Will mean 1231, if there is more then one code it will proceed to display the others, then when you notice it starting to display the same ones again you know that is all of them.

 

So you have your code, now what? Well take your number and compare to this list from e30world.com (but really from BMW themselves, they have been so kinda as to sort out the e30 relevant ones) to determine the problem:

 

Fault Code description

 

Motronic Fault Code

Malfunction

Error Description

1211

DME Control Unit

1211 – DME, Motronic computer, related fault – which may indicate problem with car computer itself. Delete any stored codes and perform following test: Start the car and let it run for 30 seconds; Turn off car and let it sit for another 30 seconds; Perform diagnostic test again; If the same flash code re-appears DME should be replaced

1215

Air Mass/Volume Sensor

1215 – Indicates problem relating to Air / Mass Flow Meter – AFM or MAF depending on your e30 model. Causes could be cable wire damage, short circuit in the unit, or air / vacuum leak (check air intake hose – big L-shaped one)

1216

Throttle Potentiometer

1216 – Designates error with potentiometer in Throttle Position sensor. Some later model cars have potentiometer, as opposed to switch (TPS) found on majority of e30 s. This code will be active if inappropriate sensor values are read by control unit, and although presence of this fault code may indicate bad potentiometer, wire harness connection at the sensor is common issue (corroded, loose connection, or broken).

1221

EGO Sensor #1

1221 – Fault related to Oxygen ( O2 ) sensor is present if the sensor is unplugged, bad / not-operational, or sensor values are out of range. Test the O2 sensor for proper operation, as well as check harness connections by the sensor and by the battery tray in the engine compartment.

1222

Lambda Control #1

1222 – Lambda control fault code is produced when Motronic system in Bosch control unit receives signal indicating that air/fuel mixture is either excessively rich or excessively lean for period of time loner then 10 seconds. Majority of the causes that affect drivability of the car can be responsible for DME flashing this error:

  • air leak
  • defective Air Flow Meter ( AFM)
  • bad engine temperature sensor
  • incorrect fuel pressure
  • problem with injector(s)
  • defective evaporation system
  • empty gas tank
  • issue with spark plugs
  • problem with valves
  • etc.

1223

Coolant Temp. Sensor

1223 – This fault code indicates problem relating to Coolant Temperature Sensor (CTS). Test the CTS sensor for proper functionality and check sensor wiring and connections.

1224

Intake Air Temp. Sensor

1224 – Fault with Air Temperature Sensor , which can indicate bad sensor, break or short in wires

1231

Battery Voltage / DME Main Relay

1231 – Battery Voltage / DME Main Relay error code can mean that battery voltage is out of range (either too high or too low), or that battery was disconnected. Test charging system and /or battery to find problem cause.

1232

Throttle Idle Switch

1232 – Error associated with “idle” portion of Throttle Position Switch. Test TPS for proper operation.

1233

Throttle WOT Switch

1233 – Error associated with “WOT” (Wide Open Throttle) portion of Throttle Position Switch. Test TPS for proper operation.

1251

Fuel Injectors (group #1)

1251 – Fuel Injectors (group #1) fault can indicate problem with either individual injector or first group of injectors. Solution is to check fuel injector connectors, wiring from DME to injectors, and to test injector(s) for proper spray pattern. Additionally, fault code 1283 could be set in conjunction with this one.

1252

Fuel Injectors (group #2)

1252 – Same as 1251

1261

Fuel Pump Relay Control

1261 – Fuel Pump Relay Control code indicates break or short circuit associated with fuel pump relay. Test for proper signal on number 3 pin on DME. It can also mean that output stage of DME is faulty (Motronic version 1.3 only)

1262

Idle Speed Actuator

1262 – Possible causes for Idle Speed Control fault are:

  • damaged wiring to the idle speed actuator
  • wire from DME is defective
  • output stage of DME is damaged

Also if engine stalls while it is above 600 RPM, code 1262 will be set

1263

Purge Valve

1263 – Purge Valve fault can indicate that Evaporative Control Valve is faulty, that wire from DME to the valve is damaged, or problem with output stage of DME (Motronic version 1.3 only)

1264

EGO Heater

1264 – EGO Heater error code is stored if there is fault with Oxygen Sensor Heather or it’s relay , Air Pump relay, supply wiring, or wire from DME

1444

No Failure

1444 – No errors

 

 

 

From <http://www.rtsauto.com/stomp-test-and-why-you-should-have-a-173-ecu-vs-153/>