Immobilizer-keyless Control Unit Input Test
WARNING: This page is about a different car, the 2009 Acura MDX, 2008 Acura MDX, and 2007 Acura MDX. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
Before testing the immobilizer-keyless control unit, troubleshoot the multiplex integrated control unit first, using B-CAN System Diagnosis Test Mode A (see
TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE A
) and check the No. 19 (20 A) and No. 7 (10 A) fuses in the under-dash fuse/relay box.
- Remove the steering column covers (see COLUMN COVER REMOVAL/INSTALLATION ).
- Disconnect the 7P connector (A) from the immobilizer-keyless control unit (B).
- Inspect the connector and socket terminals to be sure they are all making good contact.
- If the terminals are bent, loose or corroded, repair them as necessary, and recheck the system.
- If the terminals look OK, go to step 4.
- With the connector still disconnected, make these input tests at the connector.
- If any test indicates a problem, find and correct the cause, then recheck the system.
- If all the input tests prove OK, go to step 5.IMMOBILIZER-KEYLESS CONTROL UNIT INPUT
Cavity Wire Test condition Test: Desired result Possible cause if desired result is not obtained 3 LT GRN (IMOCD (S-NET)) Immobilizer-keyless control unit 7P connector, the PCM connector A (49P), and the under-dash fuse/ relay box connector Q (14P) disconnected. Check for continuity between the No. 3 terminal and the PCM connector A (49P) No. 46 terminal:
There should be continuity.An open in the wire Check for continuity between the No. 3 terminal and under-dash fuse/relay box connector Q (14P) No. 9 terminal:
There should be continuity.Check for continuity to body ground:
There should be no continuity.A short to ground in the wire 4 LT GRN (B-CAN) Immobilizer-keyless control unit 7P connector, the under-dash fuse/ relay box connector X(39P) disconnected. Check for continuity between the No. 4 terminal and under-dash fuse/relay box connector X (39P) No. 27 terminal:
There should be continuity.An open in the wire Check for continuity to body ground:
There should be no continuity.A short to ground in the wire 5 LT BLU (K-LINE) Immobilizer-keyless control unit 7P connector disconnected. Check for continuity between the No. 5 terminal and the data link connector (16P) Non terminal:
There should be continuity.An open in the wire Check for continuity to body ground:
There should be no continuity.A short to ground in the wire
- Reconnect the connector to the immobilizer-keyless control unit, and make these input tests at the connector.
- If any test indicates a problem, find and correct the cause, then recheck the system.
- If all the input tests prove OK, the immobilizer-keyless control unit must be faulty; replace it.IMMOBILIZER-KEYLESS CONTROL UNIT INPUT
Cavity Wire Test condition Test: Desired result Possible cause if desired result is not obtained 1 WHT (VBU) Under all conditions Measure the voltage to body ground:
There should be battery voltage.- Blown No. 7 (10 A) fuse in the under-dash fuse/relay box
- An open in the wire
2 BRN (IG1) Ignition switch ON (II) Measure the voltage to ground:
There should be battery voltage.- Blown No. 19 (20 A) fuse in the under-dash fuse/relay box
- An open in the wire
7 BRN (LG3) Under all conditions Measure the voltage to ground:
There should be less than 0.5 V.- Poor ground (G101)
- An open in the wire Faulty PCM
6 PNK (IG KEY SW) Ignition key inserted into the ignition switch Measure the voltage to ground:
There should be less than 0.5 V.- Poor ground (G601)
- Faulty ignition key switch
- An open in the wire