ELECTRICAL SYSTEM AND TESTING
Troubleshooting
Page 11-22
2008-2011 IQ System Electric Vehicle Maintenance and Service Supplement
11
5. If the IQDM display screen begins to work after the vehicle has been driven, turn the key switch to the
OFF position and proceed to step 6; otherwise, perform the following procedure, Tow/Run Switch Test
without the IQDM Handset.
6. With the IQDM still connected to the vehicle, place the Tow/Run Switch in the TOW position and wait 90
seconds.
7. If the IQDM display screen goes blank after 90 seconds, the Tow/Run switch and connecting wires are
operating correctly.
8. If the IQDM display screen is still active after 90 seconds, the switch has failed closed. Replace the Tow/
Run switch.
See Tow/Run Switch Removal, Section 13, Page 13-5.
Tow/Run Switch Test without the IQDM Handset
1. Set a multimeter to 200 volts DC and with the batteries connected, connect the black (–) probe to the neg-
ative post of battery no. 6 and connect red (+) probe (with insulation-piercing probe) on the light green
wire close to the two-pin connector on the Tow/Run switch.
2. With the Tow/Run switch in the RUN position, the reading should be approximately 48-50 volts. With the
switch in the TOW position, the reading should be below approximately 5 volts.
3. If the reading is above 5 volts with the switch in the TOW position, replace the switch.
4. If the reading is below 5 volts with switch in the RUN position, check continuity of the two-pin connector
and the pink 18-gauge wire from the large post of the solenoid to the two-pin connector at the Tow/Run
switch.
5. If the two-pin connector and pink wire continuity readings are correct, replace the Tow/Run switch.
6. If replacement of the Tow/Run switch does not correct the problem, check the diode on Pin 9.
Procedure 9F – Pin 9 on page 11-32.
TEST PROCEDURE 7 – BATTERY PACK VOLTAGE (UNDER LOAD)
See General Warning, Section 10, Page 10-1.
1. Before proceeding with this test procedure, the batteries must be connected and fully charged. Connect
the positive (+) lead of a 36 to 48-volt battery discharge machine (CC P/N 101831901), to battery no. 1
positive post and connect the negative (–) lead to battery no. 6 negative post. Record the voltage reading
from discharge machine.
2. Turn the discharge machine on and record the voltage reading of battery pack while under load.
3. A fully charged set of batteries in good condition should read between 46-49 volts while under load.
4. A reading of 32-46 volts indicates discharged or failed batteries. Each battery should be checked with a
multimeter while under load.
5. A reading of 32 volts or less will not activate discharge machine. If the voltage of the batteries is below
32 volts, the batteries are deeply discharged or have failed.
6. Recording the battery pack voltage reading while under load provides a more accurate diagnosis of the
condition of the batteries. When the discharge machine is ON, it places the battery pack under load and
many times can help determine if one or more batteries in the set have failed. Testing battery voltage
while the batteries are not under load will not always indicate the true condition of the batteries. For more
information about the batteries, refer to Section 14 – Batteries.