06 CRD wont crank on key but cranks bypassing starter relay

3barboost · **Joined:** Mon Mar 07, 2022 5:40 pm **Posts:** 2

Help please

06 CRD - first started out as an intermittent no start issue but now its a paperweight

Ok so heres what I can see / done and tearing hair out.......

1) Key on - everything normal - the red immo light goes on for about 2 seconds then goes off (same behaviour on both keys) red immo light doesnt flash or stay lit - if using the key - see point 8

2) trying to start - it doesnt crank, just a momentary click from the starter (very very short duration) - but its not a dead battery - battery voltage 12.9, on a charger / paralleled to another battery on the floor - if i keep the key turned to the start position, the click is every second (tonk - tonk - tonk) the radio goes off when doing this trying to start (to me that means the igntion key, key barrel, ignition switch itself is passing the "request" on)

3) if I short out the starter relay with needle nose pliers (pin 80 and 37) - the starter cranks the engine over perfectly- which is why this doesnt feel like a battery issue, and its not the wire from fise box to starter

4) starter has been pulled out and bench tested and it works perfectly

5) I have used an obd tool with a key programmer / reader addon, it verifies that both keys transponders are present and identifiable

6) the obd tool verifies that the coil around the ignition barrel is working and receiving the signal from the transponder in the key, when the tools own coil is placed around the ignition key

7) there are no codes in the SKIM / SKREEM module (there were from unplugging / re-plugging with power on, but those cleared) the only code is a known issue with right front abs sensor

ignition switch has been seperated from the key barrel so a screwdriver can actuate it - same result (the key is inserted into the SKIM antenna circle and the red immo light goes off after 2 seconds and doesnt flash / stay on - unless I force it to, by removing the key from the SKIM antenna and trying to start using the ignition switch with a screwdriver

9) the ignition key barrel rod etc - is 100% nothing broken - the behaviour on the screwdriver actuating it versus the key is 100% the same

10) Relays have been swapped over with other ones with matching part codes in the relay box - no change

So if its not the immobiliser, key switch mechanism, relays - what else is causing this ?

What wires etc could have "voltage drop" on them - seems to me the "relay" isnt being triggered hard enough by the key ?

is this a TIPM problem ?

is that possible ?

What all to check ?

open to any and all ideas on this

Thanks for reading

WWDiesel · **Posted:** Mon Jun 15, 2026 2:28 pm

Items you need to check/test:
1) terminal 86 at starter relay in the TIPM. Pull the relay and measure ohms at terminal 86 on the board when starter key switch is turned to the RUN
position.
ECM grounds this terminal to allow the starter relay to energize/engage when the ign. switch is turned to the START position. If this ground signal (ohms) is
fluctuating or weak, then the ECM is not providing a proper or continuous ground to allow the starter relay to fully engage.
2) test/read voltage at terminal 85 at the starter relay plugin on the TIPM board when the ign. switch is turned to the fully START position. You should have a 12v
steady voltage reading at this terminal when the ign. switch is turned to the fully start position to energize the starter relay. (12v coming from terminal 1/A106)

3) ASD relay, have you tried swapping it with another like size relay? It gets energized by the ECM when you turn the key to the run position if all the signals
from the items required to be able to start the engine. i.e. brake pedal switch, transmission in Park or Neutral etc...
4) You may have a bad ignition switch (electrical part)? When ign. switch is turned to the fully start position, use a voltmeter to read the voltage coming from
terminal no. 1 of the switch. This is A106 which is a DB/RD (dark blue/red) wire as shown in the enclosed diagram.
5) Clean battery cable connections at battery, check all grounds for good solid connections. A poor or weak ground can cause all kinds of weird problems.
**using a voltmeter/ohm meter, you should be able to determine where the problem is located....

3barboost · **Joined:** Mon Mar 07, 2022 5:40 pm **Posts:** 2

thank you, very very much - that diagram is legendary and super helpful as I have'nt found a diagram online for it - only dead links

Will report back on findings in a few days

06 CRD wont crank on key but cranks bypassing starter relay

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