944 Turbo KLR Bypass
Why Won’t My 944 Turbo Start?
Why Won’t My 944 Turbo Start?
If your Porsche 944 Turbo cranks but won’t start, one quick test is to bypass the KLR. On the 951, the ignition signal originates in the DME but is routed through the KLR before returning. If the KLR fails internally, that signal can die inside the KLR and never make it back to the DME. The result can be a crank-no-start condition with no ignition. This page shows how to bypass the KLR for testing by unplugging its 25-pin connector and installing a jumper between pins 9 and 16.
Important warning: This bypass is for troubleshooting only. Do not drive the car this way, and definitely do not drive it hard this way. With the KLR bypassed, you lose critical engine management funtions. If you drive the car hard or go into boost like this, engine damage is possible.
Important warning: This bypass is for troubleshooting only. Do not drive the car this way, and definitely do not drive it hard this way. With the KLR bypassed, you lose critical engine management funtions. If you drive the car hard or go into boost like this, engine damage is possible.
How to Bypass the KLR
Follow these steps to bypass the KLR and test a no-start problem on a 944 Turbo.
- Locate the KLR in the front passenger footwell.
- Remove the main 25-pin connector from the KLR.
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Make a short jumper wire using thin spade connectors and a short length of wire.
If the spade is a bit too wide to fit the connector pins, you may need to file the sides slightly until it fits. In a pinch, thick solid-core wire can be used instead. Just do not push stranded wire into the connector ports, as the risk of a signal strand shorting an adjacent pin is too high. An 18–20 gauge wire is sufficient for testing. Avoid accidental shorts to neighboring terminals.
- Identify pins 9 and 16 on the harness connector.
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Install the jumper between pins 9 and 16 of the disconnected KLR harness plug.
- Leave the KLR unplugged with the jumper installed and try to start the engine.
- Remove the jumper after testing and reconnect the KLR normally.
Assessing Results
Car starts with jumper: If your no-start 951 fires up with pins 9 and 16 jumpered, the KLR is likely faulty. Many failed KLR units can be revived by replacing the EPROM and/or reflowing cracked solder joints, so it may be worth trying those fixes before sending the KLR out for repair or replacing the unit outright.
Still no-start: If the engine still does not start with the jumper installed, something else is preventing the motor from starting. This does not prove the KLR is good necessarily, but does prove something else is preventing the car from starting.