CODE 61 XX -- RETARDER OIL TEMPERATURE HOT

WTEC III ELECTRONIC CONTROLS TROUBLESHOOTING MANUAL

CODE 61 XX -- RETARDER OIL TEMPERATURE HOT

Main code 62 indicates the retarder temperature sensor or engine coolant sensor or circuitry is providing a signal

outside the usable range of the ECU. Main code 62 can be the result of a hardware failure or an actual extremely

high or low temperature condition.

Main

Code

Subcode

Meaning

Retarder temperature sensor failed low (45C; 49F)

Retarder temperature sensor failed high (178C; 352F)

Engine coolant sensor failed low

Engine coolant sensor failed high

Active Indicator Clearing Procedure:

Power down

Manual

Self-clearing

NOTE:

Before troubleshooting, read Paragraph 56. Also, check the transmission fluid level.

Troubleshooting:

NOTE:

A combination of codes 62 23, 33 23, and 21 23 indicates a problem with one of the branches of the

common ground wire (wire 135) between the throttle and temperature sensors.

NOTE:

Code 62 12 can be caused when the +5V power line (wire 124) is shorted to ground or open. Wire 124

also provides power for the OLS, TPS, RMR, sump temperature sensor, and shift selectors and is

present in all three ECU connectors.

1. Check the retarder temperature or engine coolant temperature with a DDR. If a DDR is not

available, use the shift selector display to determine if the code is active (cycle the ignition on and

off at least once since the code was logged to clear the code's active indicator). If a condition that

is unreasonable for the current conditions exists, go to Step (3).

2. If Step (1) reveals that the extreme temperature indication is no longer present, the temperature

limit could have been reached due to operational or ambient temperature extremes. Proceed

cautiously as it is unlikely there is a sensor hardware fault.

3. Remove the connector at the ECU. Measure resistance between harness terminals T25 and T28 or

between harness terminals V9 and V24. Compare resistance value to chart (see Figure 521) to see

if reading is within expected operating range.

4. Disconnect the sensor connector and remove the connector at the ECU. Check the sensor and the

ECU terminals for dirt, corrosion, and damage. Clean or replace as necessary.

5. Check the temperature sensor circuit for opens (code 62 23 or 62 33), shorts between wires, and

short-to-ground (code 62 12 or 62 32). If a wiring problem is found, isolate and repair.

6. If no wiring problem is found, replace the retarder or engine coolant temperature sensor.

7. If the problem recurs, use a spare wire, if available, or provide a new wire (St. Clair P/N 200153

may be used for this purpose) for the retarder or engine coolant temperature circuit.

0021 00111